Saturday, January 29, 2011

【School】 combination of weak cold storage in the course of security issues】.

<br> cold meat is meat production, processing, storage, transportation and sale of an important link in the cold chain, cold storage of meat in recent years, however, frequently dangerous situations. .Reporter learned from the China Meat Association latest cold storage, only the last 6 years, cold meat made a dozen main serious injury accidents, 20 from the cold fire. .<BR> According to the China Meat Association statistics, nearly twenty thousand of existing cold storage, refrigerated cold storage volume of about 8.8 million tons, of which the cooling material about 140 million tons refrigerated cold storage, refrigerated cold storage, freezing things about 7.4 million .tons. .China Meat Association executive vice president Deng Fujiang analysis, the former state-owned enterprises accounted for the capacity of cold storage refrigeration capacity of 2 / 3; the former state-owned and non-state cold delicate  throat several Kum? 0%, agricultural products, aquatic products processing more .developed provinces of the township, 100 tons of up and down the small refrigerator is widely distributed. .Age of these cold storage library more in 10 - 30 years or so, there are safety problems. .Reporter learned that the current cold storage fire safety accidents and cooling systems for the accident. .China's meat industry, cold storage refrigeration system using ammonia as a refrigerant most. .Ammonia is in our national standard level 4 mild toxic hazard, when the volume fraction of ammonia in the air 16% - 25%, the case of fire can cause an explosion. .According to Deng Fujiang <BR> introduced in the 20th century, 90 years, commonly used in polyurethane cold insulation works, which lead to security issues affecting both the quality of the project, but also shorten the life of cold storage, could easily lead to broken, damaged, collapsed, one of the most .is a fatal fire. .Refrigeration system in recent years, accidents have occurred: compressor damage, refrigeration equipment, accidents, escape of refrigerant, cooling system pipe cracking, valve damage, failure of such safety devices are on the rise. .Why risk frequent cold conditions? .Deng Fujiang analysis that originated from six major hazards: <BR> <BR> First cold storage management disorder. .China is not yet clear which government department is responsible for cold storage security management. .<BR> <BR> Second induction operating without a license. .Cold storage is not currently in many parts of the implementation of the provisions of refrigeration system certificates. .Particular county, township, town and rural areas were not nearly cold storage holder production operators, either did not receive pre-job related training, but the lack of emergency treatment and safe operation of the daily education. .Cold storage ammonia refrigeration system in case of leakage accident, front-line operatives basic perplexed. .The third is sick refrigeration system operation. .According to statistics, built in the 20th century, 80 years before cold storage cold storage capacity is currently about half of the country, most of the library more than 30 years old. .And many enterprises have failed to provide full and on time to stay cold repair funds, causing many dilapidated refrigerator, the cold storage refrigeration system ammonia refrigerant run, run, leakage is serious. .<BR> <BR> Fourth, the lack of protective equipment of ammonia refrigerant. .Such as personal protective clothing, oxygen breathing apparatus, protective gloves and protective footwear, eye and body spray washing, etc., can not do the time for rescue, in place. .Fifth, many companies cut back on cold storage ammonia refrigeration compressor operating operating personnel, the upper management of scarce professional and technical personnel in the refrigeration, cold storage refrigeration system in automatic control technology is generally not the case, once the exception, the entire refrigeration system will .unsupervised in the state. .<BR> <BR> Sixth, cold storage design, construction and installation market confusion, undocumented design, installation of undocumented, unlicensed construction is widespread. .Because of the cold storage of insulation materials, cooling systems and pipe the reliability of the selected container, structural configuration, scientific processes such as the formation of large hidden faults, some cold storage refrigeration system with a congenital defect, security can not be guaranteed. .The current lack of cold storage safety management how to reverse the situation? .Deng Fujiang make the following observations: First Amendment promulgated by the former Bureau of Internal Trade, "cold storage building construction and acceptance norms" and the former Department of Commerce issued the "cold storage management practices" and other relevant administrative regulations. .<BR> <BR> Second is recommended that the Government authorities to allocate more public safety fund, financed and commissioned by industry associations or the cold storage business to undertake the use of the relevant countries or involving public safety industry standard preparation. .Third, require enterprises to put on cold storage security agenda, to carry out self-test self-examination, to take remedial measures against potential accidents. .Establish a standard of management and emergency management and reporting system. .Companies develop safety standards, accountability to the people. .Within the enterprise to conduct regular safety checks, there must be plans for handling accidents and the corresponding equipment. .Fourth, to strengthen the retirement of the related refrigeration pressure vessels, pressure piping pipe recovery supervision. .Must not be allowed to re-pipe waste refrigeration equipment and cold storage and cold storage to flow back to the construction site to ensure the safetyof cold storage refrigeration system of qualified materials. .Five is to ask around to do with the ammonia pressure in the pipeline register, find out the real situation, know what to do supervision on the ammonia refrigeration equipment and piping for regular inspection, and make its security evaluation. .Six is to require all companies and departments in the engineering project, bidding, design, and construction process, the strict eligibility of the involved units, to eliminate "Executive Project," "human engineering" to eliminate "edge design, the construction side, while .production "and" self-design, self-installation, self-construction ", with particular attention to the construction unit of the qualification examination of polyurethane to enhance the project site management. .<BR> <BR> Seven is to ask the associations around the meat cold storage technology and safety management training, cold storage safe each examination. .<BR>.

【School】 VOD system weak Introduction】..

<br> VOD system introduced <BR> VOD VOD: VOD (Video on Demand) video on demand, also known as interactive television on-demand system.. The traditional one-way television system information is sent, the user can only .passively receive.. The VOD is a "choice of control in the user" in the new concept of two-way video and audio based information system to achieve video and audio playback according to user needs the ideal program.. VOD is the future .information superhighway, an important part of architecture is the future of information services in the broadband services of the soul.. This technology is computer technology, network communication technology, multimedia technology, television and digital compression technology and other subjects in various fields, the product .of fusion cross * combination.. Through the VOD system can be video programs on demand, live real-time broadcasting (live online on the network), distance learning systems, remote video conferencing, remote monitoring and many other work.. Currently VOD VOD .system has been in the military, government, schools, intelligent community, hotels and other fields has been widely used.. <BR> System features: the system of the current popular use of Web browser technology, reduce, simplify the application client to .enhance the stability of the system operation, reducing the workload of system maintenance; system, the use of international and domestic standard protocol. technology, such as: network use IP, streaming video playback using advanced media player application framework using Web technology; same side .of the system used in the program memory database technology to simplify, facilitate program management.. Therefore, "ETRADE Ka Wah VOD video on demand system" is a mature real video server to the client-based, streaming video transmission using the VOD video .on demand system.. <BR> The VOD video on demand system is divided into: server management system and user-demand system.. <BR> The system is fully Web-based development, can be Internet / Intranet for seamless integration .with the following characteristics: <BR> Road, minimum performance requirements of servers: <BR> The system adopts the package of the most popular streaming media production, publishing and playback. technology to maximize the intrinsic performance of the hardware system, therefore, .production, publishing and playback software does not require additional purchase, the maximum reduction of server requirements and costs.. <BR> Road Optimal utilization of network bandwidth resources: <BR> video streaming solution of the system in the Microsoft Windows platform is .optimal, production-side with the player's video and audio quality are excellent and easy to use.. The use of the stream, each client receives the content through the network at the same time you can enjoy the show without having to first download the content .greatly reduces the wait time on the client and storage needs, but it also allows an unlimited length of the Demo, and live. broadcast.. <BR> Road Open video streaming network protocols: <BR> without special equipment or special set .of router, you can remote VOD VOD.. <BR> Road Fast video-on-demand Response: <BR> read the playback screen smooth and clear.. Support the industry's most advanced MPEG4 standard, while fully compatible with MPEG1, .MPEG2 video files and other standards may be minimal in the case of system resources to achieve DVD-level playback, true high-definition playback.. <BR> Road Video content editing simple and easy: <BR> simple, easy to use ., provides features such as pre-production, a powerful tool for video and audio editing system.. <BR> Road Any video content stored in the backup: <BR> the content of any video format, in accordance with AS easily backup ., so that use of renewable resources.. <BR> Road Zero maintenance clients: <BR> VOD system is completely Web-based development, the client can be realized using the IE browser on demand, without having to install any other software ., so that the client's zero maintenance.. <BR> Road Client terminal operation simple and easy: <BR> simply login through a browser in the terminal web server, the server will automatically log the video to achieve on-demand; in .the on-demand process, the easy free-motion video stream interception of the network,. Drag around the play, stop, fast forward, rewind, left and right channels.. <BR> Road Demand occurs during the terminal interrupted in demand .at the point of interruption when rapid recovery: <BR> remain as long as the video server to provide video services, two seconds, the terminal troubleshooting, on-demand can be interrupted at the rapid recovery.. <BR> Road And .convenient system maintenance and back office management settings: <BR> administrator can be any system maintenance and back office management settings.. <BR> Road Compatible with many media formats: <BR> encoded files can be adapted to a variety of .broadband streaming media formats, create wmv or asf files to implement on-demand.. <BR> Network environment: * HTTP-based network transport protocols and MMS video service system.. * Use of switched Ethernet (Switched Ethernet), asynchronous transfer .mode network (ATM) or Fiber Distributed Data Interface (FDDI) and other network technologies.. * Video Server via twisted pair, coaxial cable or fiber access networks, user terminals to access the LAN via twisted pair.. Broadband access and transmission networks: .10M, 100M switched Ethernet or 1000M.. * User terminal access speed: 10M or higher video server access speed: 100M, 155M or 1000M LAN <BR>..

【 Weak current College 】 DVI signal transmission in multimedia solution application 】

<br> <BR> one. using DVI signal strengths: <BR> 1. provides the best image quality.. <BR> Signal in VGA display, the notebook is the highest image quality.. CPU data to be .displayed to the graphics card to be processed to form a graphics display signal (digital signal), this digital signal directly drive LCD screen, the formation of the notebook display signal, which is the most "original" signal, not. by any treatment ., and losses.. The graphics signal (digital) through the D / A conversion, the formation of RGBHV signals, transmitted to the display device subject to approval by A / D process, to re-generate the digital signal to drive LCD and other .equipment, then the signal through the D / A,. D / A conversion, resulting in bandwidth, signal to noise ratio and other losses, such as: according to Nyquist sampling theory, the maximum analog bandwidth is only half the sample clock, and .56dB signal to noise ratio is only about (quantified by 8bit) ... However, if the graphics signal (digital) through and / serial conversion, the formation of DVI output, and then transmitted through the DVI to the display device and then only .after a serial / parallel conversion, you can directly drive LCD and other equipment, this process has not been A. / D, D / A conversion, will not cause signal loss.. <BR> 2. To reduce the signal loss during .transmission.. <BR> Analog signal transmission, because of the amplitude-frequency transmission system support and support group delay, high frequency interference, power ground interference and reflection effects of severe signal loss, works to solve the above problems and the difficulty of .dealing with. large, some even can not be solved.. But not when the digital signal transmission of these problems, the biggest advantage of digital transmission and anti-interference ability can be re-regeneration, Simply put, that is, as long as .the transfer process to ensure that "0", "1" Discrimination is not an error. receiving end of the signal is correct and non-destructive, and analog transmission in the difficult problem in the digital transfer process does not exist, this .is a fundamental solution to the problem, ensure that to the display device of the signal and laptop displays the signal as. give full play to the advantages of the display device, significantly improving the overall system display.. <BR> II. DVI .signal characteristics <BR> DVI signal theory, is the graphics to be displayed in the processed digital signal and HV RGB signal combination, according to the smallest non-zero coding, each pixel by 10hit the. → serial digital signals and convert the digital .stream encoded RG.B 4 groups with the pixel clock signal in accordance with the TMDS transmission mode, the flow rate of each channel of the original code 10 times the pixel clock to 1024 × 768 × .70 resolution, for example, pixel clock is .75MHz, the clock stream is 75MHz × 10, as 0.75GHz.. DVI-general in the 0.24GHz to 1.65GHz stream between.. <BR> DVI interface definition as shown below: <BR> <BR> DVI has .DVI1.0 and DVI2.0 two standards, which DVI1.0 of which only a group of signal transmission channel (data0-data2), transmission. The maximum pixel clock image 165M, the maximum signal transmission channel stream to 1.65GHz, the highest .resolution up to 1600 × 1200 × 60.. The DVI2.0 the two groups with all the signal transmission channel (data0-data5), transfer images to a maximum pixel clock 330M, can support 1920 × 1280 resolution, support for HDMI formats, .each channel's maximum signal transmission code. flow for 1.65GHz.. There is no DVI2.0 application, so all means are talking DVI1.0 DVI standards.. <BR> DVI defined DVI-I (Integrated) and DVI-D ( .Digital) two interfaces, can be seen from the interface definition, DVI-I DVI-D is in fact an increase on the basis of analog interface.. One view is that DVI-I is only a transitional interface will eventually develop into a DVI .-D and VGA were present situation, where we do not make improper evaluation.. We introduce DVI-D interface.. <BR> Three. DVI signal transmission problems <BR> DVI signal transmission has its particularity, that is too fast .because the data stream, making the transmission distance is limited to 1600 × 1200 × 60, for example, stipulated that can be transmitted .5 meters, in the current practice, to be completed by about 7 meters to 1280 × 1024 × 70, for .example, transfer of 10 meters is feasible.. Of course, use good cables, 1024 × 768 × 75 can be spread to 13-14 meters.. In the case of single-stage transmission, the primary problem is the problem drive capability, .that solve the "walk out" of the problem, but at the same time, even the digital signal, there are also long-distance transmission signal waveform distortion deformation, namely. After transmission by increasing the drive capability, the signal waveform to a .larger distortion of the signal received by the receiving end in "0" and "1" discrimination on the error, from the display point of view, there has been "wrong point", "wrong. point" when the .show will fail too, that no longer appear.. In fact, DVI signals over long distances, as the distance increases, the display can be observed are: good wrong point → point → → more wrong to fail.. Failure may be the signal ."walk," and can not get to the monitor, it may be "can walk", but "wrong point of" too much and failed.. <BR> Therefore DVI signal cable transmission is concerned, there are .different applications.. 1, Adepter, only the drive capability to solve the problem.. Signal input through the high-frequency amplifier, the drive to ensure that their may be some distance ahead, but is not responsible for signal shaping, can be cascaded ., it is suggested no more than three MS; 2, Repeater, when the signal input. be carried out and and and → string → string conversion, the signal will be re-shaping, and then drive through the drive circuit, which is a .forward concept.. As long as the signal does not come before the distortion level to determine the error, which produces the "wrong spot" level, then the signal sent back to class and just come out the same graphics card is the right signal .to send is at 7 meters distance. (1600 × 1200), can be cascaded, and the limited number of cascade.. 3, Line Driver, the DVI signal through a balanced approach, and after Repeater plastic handle which allows it to substantially increase .the transmission distance, an optional Line Driver 35 meters transmission distance of about (1600 × 1200), if it is 1024 × 768,. up to 45 meters, and can be infinite cascade, especially the Line Driver signals back-end applications, there .is no relay power supply problems.. <BR> DVI signals can also have other means of transmission, such as cable and optical fiber, cable ways have been discussed in the article, here only cable transmission.. The current data and practice, .through the network cable, the DVI signal means in accordance with Gigabit Net newsletter to sort and transport, 1280 × 1024 × 60 50 m can be transmitted in theory, if we can use the existing transmission cable. prospects very attractive, but inside there are .several problems, one can use Gigabit Ethernet to 1280 × 1024 × 60, resolution is not high, the actual use of this can be tolerated.. However, only one channel communication signal transmission, and DVI is also passed four signals, and signals on .the bit demanding, so cable must be specific (experiment if an ordinary network cable, can only transfer 1 - .2 m), which a lot of inconvenience for practical use, can not use existing network wire DVI signals, and then taking into account .the special converter cable prices and the price, it seems not a good choice but so suitable for general. cable look after the equipment out.. <BR> Four. DVI signal transmission performance / cost evaluation <BR> DVI signal transmission distance .according to different devices should be used in different, first cable, the cable has been able to find the current point of view, generally about 7 m to transfer (1600. × 1200), then I am afraid, something never done a long, .1280 × 1024 × 60 to to 10 meters, 1024 × 768 to go to 12-13 meters, the price of 20-40 yuan / m, other, DVI connector in the system. When demanding to do the same when the cable connector in .the technology and materials to do different, and the effect of transmission distance is different, so the price of finished product lines will be quite different.. <BR> Generally not recommended in the project Adepter, because there may be "wrong point" .;, but also in the design will not advance to consider what went wrong, especially in multi-path of the occasion, as with the Repeater, simple one, and. cost is not very different.. When the distance is more than " .a standard length "when the (1600 × 1200,7 meters), can be decided according to the distance Repeater or Line Driver, the difference is that the transmission distance of a Line Driver Repeater much larger than one, but the cost difference between a .. times.. Quo's Repeater in 1800RMB, while the Line Driver in 3400RMB or so.. $ 199 international Adepter around, Repeater $ 399 or so in the current Line Driver not found a similar product.. When the distance of 100 meters, because .the cable and the Line Driver taking into account the cost of equipment is recommended to use optical transmission, especially in certain special circumstances and occasions, on the optical transmission done before the introduction of a separate later.. But with the cable and lower the cost .of forwarding devices, optical transmission will be mainly used in ultra-long haul of the occasion.. <BR> Low cost DVI DVI transmission and the emergence of switch matrix, for paving the way for the application of DVI.. <BR> .;..

【 Weak current College 】 network video conferencing system 】

Video conference system is able to support for remote real-time information exchange and to undertake cooperative work of application systems. Video conferencing system for real-time transmission of audio and video information, so that members can tele-collaboration to make real, intuitive audio communication. On the other hand, the use of multimedia technology support, video conference system helps users work in a variety of information, such as shared data, share applications, so as to construct a lot of people shared virtual work space.
Video conference system is a modern office systems, video conference communication networks of two or more locations for multimedia conferencing Terminal, in the meantime transfer all kinds of image, voice and data signals, allowing the meeting to have on-site. Video conference system in Government Executive, commercial areas, emergency relief, disaster-proof dangers, banking systems, telemedicine, distance education, security, military operations, as well as office automation industries and areas that have a large space for development. With the social development, video conferencing application of more and more widely, both on its video and audio quality, usability, ease of use, safety and appearance of the increasingly high demands
With the development of computer networks, network video conferencing system is widely used in various industries, its high-quality audio effects, low cost, easy installation and maintenance methods, by the majority of users. The system features a comprehensive solution
1. network
You can share via ADSL, broadband, wireless, WIFI, network, support intranet through gateways, proxies, NAT, routers, Internet network environment
You need at least 1 MCU. Multiple MCU can ability with cross interconnect support traffic load balanced to reduce backbone bandwidth
A single MCU can support to 50-100 venue for meeting
MCU with support for network fault line fault tolerance technology resume,
3, Terminal
Can use notebook, PC, phone, Terminal Conference
Support for standard series Terminal H323 calling and communication
4. main attachment: echo canceller

System characteristics: reliable MCU deployment

System characteristics: high-quality audio effects
A variety of video encoding protocol embedded
1. system built-in: H.263, H.264, H.263 +
2, the video resolution (with digital zoom): 160 * 120, 176 * 144, 176, 240 * 320 * 240, 352 * 288, 480 * 352, 640 * 480, 702 * 576
Multiple audio encoding protocol embedded
1. system built-in: GSM, G.711, G.723, G.726, MP3, etc.
2. automatic noise reduction and echo cancellation system features: advanced data conferencing solutions
Industry-leading data conferencing technology: dual stream technology
Features include:-screen video, digital white board, file transfer, text-chat

System characteristics: practicality, rich with features

System characteristics: convenient, fast way

System characteristics: reliable and effective management strategy management functions: hierarchical management —--structure is clear, the responsibility to the people
Structural unity-user account management, unified authentication

System characteristics: strong and reliable system security
First, the MCU system security policy
1. WEB page data encryption algorithms.
SSL (SecureSocketLayer) Secure Sockets Layer Protocol
DES digital encryption
2, Visual, audio, data, etc. for the MD5 128-bit encryption.
3. it supports through a third-party cryptographic algorithms for encryption, such as hardware encryption machine.
Second, terminal security policy
1, when a user logs on to the system, all your account's password through 128-bit encryption algorithms for encryption, and transport, this ensures that even if someone eavesdropping on the network data and cannot know the exact password in the database, all of the user account password is also stored encrypted.
2, network video system using double privilege authentication management, ensure that the information does not leak, for non-compliance disciplined personnel, you can immediately put him out of the Conference room. System features: from the desktop to the Conference Room of the complete application

System summary
1, it is a set of larger scale deployment, reliable applications.
2, it takes full advantage of your existing equipment is a high performance application system.
3, it not only applies to meeting and also with the daily Office, business training.
4, support standard telephony gateway that enables mobile users to join the meeting, the Conference application is not restricted.
5, can be used with standard 323 interconnection equipment, so that the original investment is protected.
6. use of the powerful, convenient and concise.
7. system security. System model: the main meeting room application
Sub main conference room and meeting room mode mode, support for multiple layout template
Advanced control features and multiple host tile painting mode.

System model: meeting room application

System mode: remote discussions and training
Primary classroom projector a primary classroom teacher image: student image projector II
You can continue to increase the projector to show more of the video. You can adjust the image number. System model: desktop-application

Move the user's mode

Deploying 1

Deployment 2
1, video conference system core configuration
In the Network Center and a number of places specified by the County Council, secondary MCU device comprised of MCU clusters. To achieve load balancing, and disaster redundant aims to maximize the use of reliability guaranteed.
2, 12-room systemBR > in urban centres and 5 counties, three meeting rooms, all of the stations equipped with a private conference room, computer, and the other with a SONY camera EVID100 meeting room and conference dedicated MIC. Easy organization of multiple participants of conferences;
3, 110 enforcement Office desktop applications
A total of 110 meters, convenient base enforcement Office at any time, and the competent unit instant task orders and work exchanges.
4, system expansion
If you need to increase the number of terminals, you can use the server's capacity to implement, without prejudice to the existing system. Deploy 3
1, computer: P4 2.4G 512M 40G 64M GF2
2. camera gun: SONY D100 or D70
3, display equipment: projection or plasma
4. video capture card: BT878
5, Echo Canceller: AVEC2000WB
6, Room MIC: AV709
7, conference rooms and audio equipment, etc.

Conference room equipment configuration deployment 4

【 Weak current College 】 MCU hardware design experience 】

(1) in the components of the layout should be interrelated components to put close to some, for example, clock generator, crystal oscillator, CPU clock input noise is easy to produce, in place of time should bring them nearer. For those who are easy to produce noise of devices, low-current circuit, high-current circuit-switching circuits, etc., should, as far as possible away from the microprocessor logic control circuitry and memory (ROM, RAM), if possible, can be made of the circuit in addition to facilitate anti-interference circuit board, improve the reliability of the circuit.

(2) as far as key components, such as ROM, RAM and other chip decoupling capacitor is installed next. In fact, PCB wiring, wiring and connector pin and so may contain large inductive effect. Large inductance might Vcc alignment caused serious switching noise spikes. Prevent the Vcc alignment on switching noise Spike's unique approach, is in the VCC and power between the places a 0.1uF e decoupling capacitor. If the circuit board using surface mount components, you can use the sheet capacitance directly next to a symbol, fixed in the VCC PIN. It is best to use ceramic capacitors, this is because such capacitors with low electrostatic dissipation (ESL) and high-frequency impedance, this capacitor temperature and time media stability is also very good. Try not to use tantalum capacitor, because in the high frequency of impedance under it.

Seated decoupling capacitor, take note of the following:

· In printed circuit boards of power input crossover 100uF of electrolytic capacitors, if volume allows, electrical capacity larger is better.

· In principle each IC chip are placed next to one of the ceramic capacitor 0.01uF, if the Board of the gap is too small and placement, the can around every 10 chips, place a 1-10 of tantalum capacitor.

· For a antijamming ability weak, turn-off time current change large components and RAM, ROM, and other storage components, should be in the power cable (Vcc) and ground between access decoupling capacitor.

· Capacitor leads not too long, especially high-frequency bypass capacitor cannot lead.

(3) in the microcomputer control system, the ground of many kinds, systematically, shield and, logically, analog, and whether the layout is reasonable, the ground will determine PCB anti-interference ability. In the design of the ground and pick up spot, you should consider the following issues:

· Logic and analog to separate wiring, can not be combined, will their ground with appropriate power ground wire. At design time, simulation of the ground should be bold, and try to increase the leadout area of the grounding. In General, for input and output of analog signals, and microcontroller circuit between the best isolation through optical coupling.

· In the design of logic circuits for printed circuit board, its ground-loop form should constitute, improve circuit anti-interference ability.

· Ground should be as rough. If the ground is very thin, ground resistance will be larger, ground potential with current changes, causing the signal level instability, leading to the descent of anti-interference ability. In the wiring space permitting, to ensure that the main ground of the width of at least 2 ~ 3mm above symbol pin grounded around the 1.5mm.

· It is necessary to pay attention to the choice of receiving stations. When the signal frequency is lower than on the Board, because of the wiring 1MHz and components between electromagnetic induction to low impact, and earthing circuit formation in circulating on the interference of the larger, so you want to use a little grounding, so it does not form a loop. When the signal frequency is higher than on the Board, because of the wiring 10MHz inductance effect obvious, ground impedance becomes very large, ground circuit formation of circulation is no longer a major problem. So should adopt more grounded, minimize ground impedance.

· Power cable in addition to the layout according to the current size as far as possible, bold line width, the wiring, the power cable and the ground of alignment direction and data line alignment to the parties as agreed at the layout of the final, with ground wire to the back of the circuit board without alignment of fill, these methods will help to strengthen the capacity of anti-interference circuit.

· Data line width and wide as possible, to reduce resistance. Data line width at least not less than 0.3mm (12mil), if you use 0.46 ~ 0.5mm (18mil ~ 20mil) is more ideal.

· Due to circuit board of a through-hole will create about 10pF of capacitive effect, high frequency circuit, will introduce too much interference, wiring, you should minimize the number of the hole. Again, too many hole also reduces the mechanical strength of the Board.

A microcontroller hardware circuit design contains two parts: one is a system extension that SCM internal functional unit, such as RAM, ROM, I/O, timer/counter, interrupt system does not meet the requirements of the application system must be extended outside the movie, select the appropriate devices, appropriate circuit design. Second, the system's configuration, that is, in accordance with the system functional requirements configured peripherals such as keyboards, monitors, printers, A/D and D/A converters, etc., to design the appropriate interface circuit.

System extensions and configuration should observe the following principles:

1. Select a typical circuit as possible, and in accordance with the MCU general usage. For hardware system of standardization, and modularization and lay a good foundation.

2, system expansion and peripheral configuration level should fully meet the functional requirements of the application system, and have a proper room for secondary development.

3. hardware structure should be considered in conjunction with application software programmes. Hardware and software solutions will produce mutual influence, considering the principle is: the software can achieve the functions of the software as much as possible, the real threat to simplify hardware structure. But it is important to note that the software and hardware featuresThe general response time than hardware implementation is long, and CPU time.

4. the system of related devices to ensure performance to match. If you choose CMOS chip MCU low power systems, system all chip should as far as possible, choose a low-power products.

5, reliability, and anti-jamming design is an essential part of the hardware design, including chips, device choice, decoupling filter, PCB wiring, channel isolation, etc.

6, microcontroller peripheral circuits are more, you must consider its drive capability. Drive capacity is low, the system is not reliable, can be enhanced through the addition of line drive driving capability or reduce the power consumption to reduce bus load.

7. as far as possible towards the "monolithic" direction design hardware system. System device, the device also mutual interference between the stronger, the power consumption increases, also inevitably reduce the system's stability. With the single-chip integrated functionality more and more strong, a real on-chip SoC can implement the system, such as the newly launched ST company μ P S D 32 ¡á ¡á series product in a chip integrates 80C32 nuclear and large-capacity FLASH memory, SRAM, A/D, I/O, two serial ports, watchdog, power-on reset circuit and so on.

SCM system hardware commonly used method of practice in anti-jamming

Affect the safe operation of the single-chip system reliable factors comes mainly from the system of internal and external electrical interference and protected by the system structure and design, component selection, installation, the manufacturing process. These constitute the single-chip system, often causing interferenceSCM system disorders, ranging from affecting product quality and yield, to cause accidents that result in major economic loss.

Form the basic elements of disturbance are three: (1) the source of interference. Means of interfering components, equipment, or a signal, using a mathematical language description: du/dt and di/dt Grand place is the source of interference. For example: Thunder and lightning, relays, SCR, motor, high-frequency clock, etc can become the source of interference. (2) propagation path. Means interference from sources of interference to access sensitive devices or media. Typical interference propagation path through the wires of conduction and radiation in space. (3) sensitive devices. Means easily interfere with objects. Example: A/D and D/A Converters Microcontroller and digital ICS, weak signal amplifiers, etc. Interference category 1 interference category interference category has a good variety, can often be the cause of the noise, transmission mode, waveform characteristics etc for different categories. The causes can be divided into the discharge: noise, high frequency oscillation noise, surge noise. By the way: transmission can be divided into common mode noise and noise series mould. By: waveform can be divided into continuous sine wave, pulse voltage and pulse sequences, and so on. 2 interference of coupling interference interference signal is coupled through a certain channel is an impact on measurement and control system. Therefore, I have the need to look at the source of interference and noise passed between objects. Interference of coupling mode, simply through the conductor, space, public line and so on, broken down, there are the following: (1) direct coupling: this is the most direct way is also the most widely present in the system. Such as the interfering signal through the power line breaking into a system. (2) public impedance coupled: this is a common way of coupling, it often occurs in two circuit current common pathway. In order to prevent this kind of coupling, usually in circuit design to consider. The source of interference and tampering with no common impedance between objects. (3) capacitance coupling: also known as electric coupling or electrostatic discharge coupling. Because of the existence of the distribution capacity of the coupling. (4) electromagnetic coupling: also known as magnetic coupling. Is due to the distribution of coupling of electromagnetic induction. (5) leakage coupling: This coupling is purely resistive, insulation is not good when it happens.

Common hardware anti-interference technology for forming the three elements of disturbance, interference of the following methods. 1 interference suppression of interference is possible to reduce the interference source du/dt and di/dt. This is a antijamming design of the highest priority and the most important principle, often has a multiplier effect. Reduce interference sources du/dt, mainly through the interference source to achieve parallel capacitance at both ends. Reduce the interference of the di/dt is interference source loop inductance or resistance and increase continued flow diode. Suppression of interference sources of common measures are as follows: (1) relay coil increase continued flow diode, eliminating broken coil of back-EMF. Only with continued flow diode will enable relay disconnect time lag, increase the Zener diode rear relay in unit time action more often. (2) the ends of the relay contacts and add spark suppression circuit (typically RC series circuit, general elections a few K resistor to dozens of K, capacitors selected 0.01uF), decrease the EDM. (3) to the motor and filter circuit, capacitors, inductors leads to short. (4) the Board each IC to and received a 0.01 μ F ~ than 0 μ F high-frequency capacitors to reduce the effect of the power supply IC. Note the high-frequency capacitance of wiring, wiring should be close to the power supply side and short thick as possible, otherwise, equal to increase the capacitance of the equivalent series resistance, affect the filter effect. (5) wiring avoid 90 ° bend, reduce the high frequency noise emission. (6) thyristor suppression received on both sides and RC circuits, reduce the noise generated by Silicon controlled rectifier (this noise serious may be SCR breakdown). 2 cut off interference propagation path by interference propagation path can be divided into conducted interference and radiated interference. The so-called conducted interference is defined through the wire to sensitive devices. High-frequency interference noise and useful signal frequency bands, can lead to increase filter method for cutting high-frequency interference noise transmission, sometimes can also be combined with optical coupling isolation. Power noise hazards maximum, paying special attention to the process. The so-called radiated interference is propagated through space radiation sensitive devices. The general solution is to increase the interference sources and sensitive devices distance ground their isolation and in sensitive devices on the short hood. Cut the noise propagation path of common measures are as follows: (1) take full account of the power on microprocessor shadowRing. The power to do well, the entire circuit interference most of the settlement. Many of the microcontroller is sensitive to the power supply noise, to give single-chip power plus filter circuit or regulators to reduce power noise interference on the microcontroller. For example, you can use beads and capacitance constituted π-shaped filter circuit, course conditions requirements is also available in 100 Ω resistor substitute beads. (2) if the microcontroller I/O port used to control the motor noise, and the i/o port should be added between the noise source isolation (increase the π-filter). (3) Note Crystal wiring. Crystal oscillator and a microcomputer PIN as close as possible to that ground the clock district isolation, Crystal shell grounding and fixed. (4) reasonable partition, such as circuit boards, weak signal, digital and analog signals. As far as possible sources of interference (e.g. motors, relays) and sensitive components (such as SCM) away. (5) with a ground to digital and analog in isolation. Digital and analog to detach, point final in received power. A/D and D/A chip wiring also this principle. (6) MCU and high-power devices ground to separate ground to reduce interference. High-power devices in the circuit board edge as possible. (7) on-chip I/O port, power cables, printed circuit board connectors, and other key parts of the anti-jamming components such as beads, steepness, power filter, shielding enclosures, can significantly improve the performance of the circuit. 3 improve sensitive devices of anti-interference performance sensitive devices of anti-interference performance is from the sensitive devices here consider minimizing interference noise pickup, and never a normal status as soon as possible. Improve sensitive devices anti-interference performance of common measures are as follows: (1) wiring to minimize the loop area, central to reduce induced noise. (2) wiring, power and ground to rough. In addition to reduce pressure drop, and more importantly reduce coupling noise. (3) in the case of single-chip I/O port are idle, not vacant, to ground or power supply. Other IC free-without altering the system logic ground or power supply. (4) on-chip power monitoring and watchdog circuit, such as: IMP809, IMP706, IMP813, X5043, X5045, can greatly improve the performance of the entire circuit. (5) in speed to meet the requirements, minimize the use of Crystal and low-speed digital circuits. (6) IC devices try to direct welding at the Board, the use of IC socket. 4 other common anti-jamming measure AC side inductance capacitor filter: removes the high frequency pulse-frequency interference. Transformer-isolated measures: transformer primary input thread capacitance, primary and secondary coils shield and the primary contact between the capacitor Centre, secondary external geodetic shield received printed circuit board, this is a hardware key anti-jamming. Secondary plus low-pass filter: absorption of surge voltage transformer. Integrated DC regulated power supply: because of the over-current, over-voltage and over-temperature protection. I/O port using opto-electronic, magnetic, relays, while eliminating common ground. Communication wires twisted pair: exclude parallel mutual inductance. Lightning most effective with optical isolation. A/D conversion with isolation amplifier or on-site conversion: reducing errors. Shell geodetic: solve personal safety and prevention of external electromagnetic interference. Added reset voltage detecting circuit. Prevent reset is not sufficient, the CPU is working, in particular with EEPROM device, reset not fully will change the contents of the EEPROM. Printed circuit board Technics anti-interference: ① power cord bold, reasonable alignment, grounding, three bus separately to reduce mutual inductance oscillation. ② C P U, RAM, ROM, and so the main chip, between VCC and GND and received Electrolytic Capacitor ceramic capacitors, high-frequency interference removal. ③ independent system structure, reducing connector and wiring, increase reliability, reduce the failure rate. ④ manifold and socket access reliable, socket, it is best to use a closely integrated block direct welding in printed circuit board, prevent devices access to undesirable fault. ⑤ conditional using four layers above PCB, the middle two layers for power and ground.

Weak current College】 【video related terminology list (2)】.

A more detailed explanation: suppose we have 10 seconds to 10 seconds of video and audio fragments. Each second of video audio with V said, with A representation that if your interlaced set to 10 seconds, a file on disk will be VVVVVVVVVVAAAAAAAAAA forms. If alternate is set to 1 second here is: VAVAVAVAVAVAVAVAVA.


Telecine for reverse engineering. This process will be the ones to 29.97fps original 24fps.

Keyframe keyframes

A full frame (frame), but this frame is compressed as possible.


The two terms were as MPEG-1 and MPEG-2 video data extensions (only video that does not contain any audio).


MPEG is a dynamic image experts group (MotionPictureExpertGroup), usually it is the source of the video format. This expert group explains digital video standards (or standard), including MPEG1 (VCD), MPEG2 standard (for DVD and SVCD), MPEG4 standard as well as several audio standards including MP3 and AAC. Use MPEG-1 or MPEG-2 standard video usually to .mpg or .mpeg as the extension.


MPEG4 is MPEG expert group (MPEGGroup) identified a series of standards (or standard), it will become the next digital video standards (mainly used for video telephony and streaming media on the Internet and more). MPEG4 allow using various encoding, such as a key frame can use ICT or Wavelet to get different output quality.


MPEG MPG can be thought of as an abbreviation, or as MPEG-1 and MPEG-2 video data extension.


MultipleMPEG4: different bitrate encoding file combination. for example, you can put 2000kbit/s and 910kbit/s encoded files are combined, using the bitrate lower file, replace the file as and 2000kbit/s part of too much and cause serious distortion of the picture here can also be two DIVX encoding combination: you may leave the lower MOTION and high MOTION files together (here you can also use a different bit rate).

Multipassencoding multi-channel coding

Before you read: current real multi-pathing encoding only exist WM8 and MPEG-2 (SCVD and miniDVD). M4C is not a true multi-channel encoding (read M4C Guide to find it actually is and how to work). A support channel encoding will be the first pathway analysis will be encoded video flow and put it face down anything. Suppose we have a dialogue scene started small fragments, which has very little cut and remain stationary cameras. And then it becomes a fight to defeat hand road, there are plenty of fast cutting and action (people flying in the sky, kick, punch, and so on). In normal CBR encoding per second will be approximately the same bitrate (hard to maintain 100% of the CBR but that is minor) but in multi-pathing VBR mode encoding will be based on a video stream of information to use the appropriate bit rate, that means the dialogue parts receive enough bitrate and the fighting part for higher bit rate. Access more bitrate, the more detailed the allocation. In a single pass VBR encoding must only in accordance with its earlier coding things knowledge to decide how many bit rates.

Wavelength division Multiplexing

Usually the video and audio is encoded separately. Then you must put them together in order to become you can play movies (of course you can in two player to play audio and video, respectively, but synchronization will become very difficult). In the reuse of audio and video tracks synthesis into an audio/video stream. Audio and video streaming seems intertwined, and include navigation information, so that the player can withdraw in fast forward/fast sampling in AV sync.

Normalizing standardization

Standardization include finding a track of peak capacity, and then increase the track to the same level of the rest. This is usually done in WAV level, that means all of the variables are integers so accurate than DRC. So in the standardization of DRC more loved.


OGM, OGg Media that was made for Oggcontainer TobiasWaldvogel additions, OGM can be seen as another AVIcontainer, it can contain OggVorbis, MP3, AC3 audio, all kinds of video format, paragraphs, and subtitles.


PGC ProGramChain said. It is a DVD compilation of frequently used terms, is basically a simultaneous playback. For example, film major part has its own PGC, DVD every trailer usually have their own PGC. When you play a disc when Studio logo has its own PGC, and so on. SmartRipper movie mode and DVDDecrypter in IFO mode will show you on a DVDAll of the PFC. For additional information about PGC & # 39 see MPUCoder; sDVDinformationsite website.

Progressive progressive scan

And interlaced (interlaced). A only includes full frame (frames) of the video stream is considered to be in. de-interlace progressive/interlaced videobasics knowledge as described.

Quantizer quantization factor

To truly understand this term you must learn signal processing courses. In general terms it means that the compression factor. The higher the value, an image is compressed, the more (and therefore high quantization factor means low image quality and small footprint and low quantization factor means that high image quality and space).

Rff/tff mark

RFF said repeatfirstframe (repeat first frame), it is used to convert the source to record 24 frames per second movie conversion as needed per second 29.97 frame technology. Using rff tag encoding movies-tag tells the player repeats. Tff represents the first is on top of the field and is used to achieve the telecine to 24fps 29.97fps film making for.


In this regard there is a lot of confusion. Basically, ripping the DVD movie copy that into your hard disk. This includes the DVD drive of the authentication (authentication) process (trying to copy from DVD to the next file, you will see a message: If your drive has not been proven that the operation is not supported) and a real CSS decoding (Descrambling) process. CSS (ContentatedScramblingSystem data interference system) is designed to prevent unauthorized copies of copy DVD movie, although many people argued that it is designed to control the DVD movie you can play, because there is no CSS license to play the DVD movie you essentially have to crack the encryption off-I very much agree with this. Ripping this word is often used (even this site) describes the entire process of decoding a DVD, and then put the audio and video conversion is called another-less-format.


SmartBitrateControl smart bit rate control. A novel called the DivX encoder Nandub in the compresses the dynamic modification during many internal parameters, give you a better quality and more control of the encoding. More information you can see Guidelines section of DivX SBC guidelines.

Streamlist stream directory

Stream directory is a path name and file name of your VOB files ASCII test, row a file. Here is a small example:

Save the file as streamlist.txt or streamlist.lst. Make sure that you save as format of ASCII text, I suggest you use Notepad to edit your current directory, because Notepad will not be saved into another format. MPeg2avi request stream directory extension is lst, however in other programs using the stream directory when you are free to choose any extension. But the GUI in the select input file name/extension is restricted, therefore if the stream directory is not in the file selection dialog box appears, then you must rename your current directory.


Put the ones into 24fps 29.97fps or 29.97x2 interlaced fields per second.


Variable-rate. Connect the audio and video are in VBR mode encoding is possible throughout the file bit rate is not fixed (as in fixed in CBR), video/audio in more complex sections will use a higher bit rate to get a better feel of the Visual/auditory, while other parts you get less bitrate.


Variable key frame interval. That basically means that the need for keyframes where no longer as usual DivX codec does follow a fixed interval insertion. There are two ways to achieve the VKI method: the first method is to unpack the compressed frames of the encoder, the comparison with the original, if the quality difference is greater than a set limit value is re-encoded. This encoding method is only applicable to a specific program: M4C. There is a command line version and one donor AviUtl plug-in (the latter in AviUtl is described in detail in the Wizard). If the limit values set too high then you will get a number of key frame of the second approach, its mainly in scene change when inserting keyframes. To this end coding programs or codecs will detect where there is a so-called "cut" (like film producers are using) exists and that the new scene the first frame of a keyframe. This can be done using mpeg2aviAr (AviRevolution part), or by installing DivXVK m4cI codec. If you use the latter don't have to worry about the encoder. Each can be DivX encoding programs can make the files in a scene change. When the VKI is reasonably used (only applies to the first method) that can help you increase or decrease in the number of key frames, so get higher quality again, this is because especially in the low bit-rate, too many keyframes will bring worse quality.


VKI + MM4 + VBRMP3 abbreviation


VOBID used to be a PGC DVD Cell within the group.


All DVD movies are stored in the vob file. Vob files usually contain mixed in Dolby Digital audio and MPEG2 format video. Vob files are named as follows: vts_XX_y.vob where XX represents the title of the heading Y represents a part of. In total there are 99 titles and 10 parts, although vts_XX_0.vob never include any video, usually just menu or navigation information. There are two ways to find out which file contains the body of the film:

Method 1: use the DVD player to play the movie, and observe the LEDs single machine or software player's status window.

Method 2: the movie's main digital continuous vob file in the digital Max. For example, have vts_05_1.vob;

Vts_05_2.vob ... vts_05_8.vob (I've never seen a partial file contains 9 movies, but that doesn't mean that does not exist).


VTS is the short name of the video title set, i.e. is a VOB file and the corresponding IFO and BUP files collection. For example, VTS2 will contain VTS_02_0.VOB (contains menu), VTS_02_1.VOB, VTS_02_2.VOB, etc., as well as VTS_02_0.IFO and VTS_02_0.BUP, etc. files. VTS is used to move the video material as well as its subsidiary files grouped together. For example, a VTS normally used for the main movie (and sometimes also including trailer and some movie company logo), other VTS for tidbits.


Microsoft copyright PC audio and video systems-it is based on a series of codes, these codes are used to play any WindowsMediaPlayer its supported format files-the latest version of the WindowsMediaPlayer is 7.0 .WindowsMedia7.0 offers a range of new code, including a fully compatible with ISO MPEG4 encoding (called WindowsVideoV1), one of the named MSVideoV7 improves MPEG-4 encoding (although I did not find it and compared based on DivX MSWindowsVideoV3 of any improvements), this kind of encoding support Deinterlacing and InverseTelecine.


EXtendedCD is an upcoming (can be translated as the next generation? feel less suitable) CD format, which allows the use of mode2 form the second way to burn your CD, this basically means that it contains fewer check code, so you can single CD store more data. XCD allows you in a plain 700MBCD store 800MB data. As I have said so, since only less check code, XCD is not very reliable, it is recommended that you only put the container with additional checking of data (such as OGM) on this CD.


XviD is a word game. Turn it upside down to read, and you'll see a familiar words. XviD is an open source MPEG-4 codec, which you can get the best DivX codec better results. XviD's home page can be seen here.

【 Weak current College 】 what is ESD (electrostatic discharge) 】

Electrostatic discharge (ESD, electrostaticdischarge) is in the electronic Assembly and component damage in circuit board of a familiar but underestimated origins. It affects every manufacturer, no allowed size. Although many people think they are in ESD-safe environment, the production of the product, but in fact, ESD-related damage to continue to the world of electronics manufacturing industry billions of dollars each year.

ESD? electrostatic discharge (ESD) is defined as, to or from the original already have static (fixed) charge (e or surplus) discharge (electron flow). Electric charge in two condition is stable:

When it "in" electrical insulation; electrical conductivity; but, such as objects, there is a metal with plastic handle with a screwdriver.

When it stay in insulated surface (e.g. plastic), cannot flow above.

However, if the charge with a sufficiently high electrical insulation conductor (screwdriver), close to the contrary potential of integrated circuit (IC), charge the "crossover", caused by electrostatic discharge (ESD).

ESD to extremely high strength occurs very quickly, usually will generate enough heat to melt the internal circuit semiconductor chips, in electron micrograph outer appearance to blow out of small bullet holes, causing instant and irreversible damage.

More seriously, this kind of harm only one tenth of the bad to cause in the final testing of the entire component failure. The other 90%, ESD damage caused only part of the demotion-means that the damaged components can be silently through the last test, but is shipped to the customer after the premature failure of the site. The result is the loss of reputation, for a manufacturer to correct any manufacturing defect where most pay.

However, the main difficulties in ESD control is that it is not visible, but you can achieve the damage electronic components. Audible "ticking" a sound of discharge requires the accumulation of approximately 2000 volts rather larger charge and 3000 volts can feel small electric shock, 5000-Volt can see sparks.

For example, such as complementary metal oxide semiconductor (CMOS, complementarymetaloxidesemiconductor) or electrical programmable read only memory (EPROM, electricallprogrammableread-onlymemory) these common elements, were only 250 v and 100 v ESD electric potential difference is destroyed, but more and more sensitive of modern components, including the Pentium processor, as long as 5 volt can be destroyed.

The problem is caused by damage in a day of activities combined together. For example, from vinyl factory floor walk the floor surface and rubbing between shoes. The result is pure charge of objects, cumulative reach 3 to 2000 Volt charge, depending on local air humidity of equivalent.

Even workers in the stage of the natural movement of the friction can produce 400 ~ 6000 volts. If the voiding or packing foam cartridge or bubble bag of PCB, the worker has processed insulator, the workers body surface accumulated net charge up to around 26000 volts.

Therefore, as the main source of ESD damage, all entered the ESD protection zone (EPA, electrostaticprotectedarea) of staff must be grounded to prevent any charge accumulation, and all the surface should be ground to keep everything the same electric potential, prevent ESD occurs.

To prevent ESD's main product is a bowl of belt (wristband), kinky corduroy and dissipative surface or bedding-both of which must be properly grounded. Additional AIDS such as dissipative footwear or heel belt and suitable clothing, are designed to prevent personnel in ESD protection zone (EPA) cumulative and maintain when you move the net charge.

During and after the Assembly, PCB should prevent from internal and surface transport in ESD. There are a number of circuit board packaging products can be used for this connection, including shielding bags, shipping boxes and removable trolley. Although the correct use of these devices will prevent 90 percent of ESD-related issues, but for the last 10% takes another kind of protection: ionization.

And those who can produce the electrostatic charge of Assembly equipment and surfaces the most effective method is to use the ion generator (ionizer)-a device blowing out ionization air flow in the work area, and accumulated in the insulation of any charge.

A common fallacy is that because the workstation with the bowl with the insulator in the region, such as polystyrene Cup or cardboard boxes, the charge will be safely dissipated. By definition, an insulator is not electrically conductive, except through ionization cannot discharge.

If a charge of insulators remain in EPA, it will radiate an electrostatic field, raises net charge to any nearby object, thereby increasing the damage to the product of ESD. Although many manufacturers attempt to ban from the EPA, but the insulating material is very difficult to implement. Insulating material is daily life too much part-from the operator is located and comfortable foam pad, that some of the plastic cover.

As a result of the use of ion generator, manufacturers can accept some insulation material in the EPA in fact. Because ion system continuously and may occur in any charge above insulator, so for any of the ESD programme, they are a reasonable investment.

Standard electronic assembly equipment, ion occurs in two basic forms:

Desktop (a single fan)

Over the top of the device (in a single over the top of the unit, there is a series of fan)

There are indoor ion generator, but it is mainly used for clean room environment.

> Select the need to protect the area. Desktop ion generator will override the single work surface, and over the top-ion generator will cover two or three. Another advantage is the ion generator also prevent dust and electrostatic attached to product may give rise to an appearance of degraded.

However, without the validity of the ESD equipment and monitoring of normal testing, then none of the protection scheme is perfect. First-class ESD control and ionization expert reports on the use of (and therefore useless) ESD equipment and do not know the manufacturer of its failure.

In order to prevent this situation, in addition to the standard equipment of ESD, ESD vendors also provide constant monitor, if a performance is out of the automatic alarm. Monitor can be used as a stand-alone unit or in network connections. Also has automatic data acquisition of network software, real-time display of the relevant operator and workstation system performance.

The Profiler can eliminate many daily tasks to simplify the ESD programme, such as ensuring proper measurements per day with a bowl, ion generator of balance and the correct maintenance, no damage to Earth point of table.

Conclusions of the

Prevent ESD of the first step is to evaluate if neglected, how small details may result in irreparable damage. An effective scheme requires not only use effective ESD protection devices, and rigorous operational procedures to ensure that all factory ground personnel are ESD safe.

Although many manufacturers use automatic bowls with tester, but often you can see the operator because the bowl with a too loose, or by testing or failure. Many operator tries to use the other hand simple hold Tester close to their wrists to the test.

ESD protection circuit design

Electrostatic discharge (ESD) will give electronics fatal hazards, it not only reduces the reliability of the product, increased maintenance cost and is not in line with the European Community provides industry standard EN61000-4-2, the product cannot be sold in Europe. Therefore, electronic equipment manufacturers often at circuit design of the early consideration of ESD protection. This article will discuss the ESD protection circuit in several ways.


ESD is basically divided into three types, a variety of machines due to ESD, furniture move or move equipment, three due to ESD is human contact or equipment caused by ESD movement. These various ESD for semiconductor production and production of electronic products are very important. Electronic products in use are the most vulnerable third ESD damage, portable electronic products are particularly vulnerable to human contact damage of ESD. In normal circumstances ESD damage connected to interface devices, another case was subjected to ESD shock after the device may not be damaged, but the performance degradation cause products to fail prematurely.

When the integrated circuit (IC) to withstand ESD, discharge circuit resistance is usually very small, cannot limit the discharge current. For example, the static electricity cable plugged into a circuit interface, discharge circuit resistance almost zero, resulting in up to 10 amps peak instantaneous discharge current, flows into the IC PIN. The instantaneous current would seriously damage IC, local heating of heat even melt silicon chips. ESD damage to IC also includes internal metal connection was blowing, passivation layer, transistor unit is burned. ESD will cause the deadlock IC (LATCHUP). This effect and CMOS device internal structure similar to the thyristor unit is activated. High voltage to activate these structure, formation and high current channels, usually from VCC to land. Serial interface device deadlock currents up to 1A. Deadlock will remain current until the device is powered off. But by that time, the IC is usually already hot and burnt. ESD shock may exist two is not easy to be found, the average user and IEC test institutions use the traditional method of "feedback loop" and "Insert method" for testing, you typically cannot detect.

One problem is the RS-232 interface circuit sink on transmitter produces cross-talk. Products of the same RS-232 interface circuit ESD protection structure may be on a wave of ESD ESD or a failure, after impulse voltage ESD shock after input of the receiver and the transmitter output between the access road, causing the receiver to the transmitter produce pay increase (Figure 1). If RS-232 interface circuits for off road, then turn off period after ESD shock after more easily generate alternating current. Produced by alternating will lead to a communication failure and even shut off the status of the transmitter still have output, resulting in failure to turn off each other in the receiving State RS-232.

Another problem is the RS-232 interface circuits for power generation reverse driver. Some RS-232 interface circuit ESD protection structure through ESD shock may result in input and VCC power supply between the current path (Figure 2), on the reverse driver power supply. If the power supply does not have the ability to breathe in-current (typically power output circuit has a forward diode), which will cause the power supply voltage VCC rise, resulting in damage to the RS-232 interface circuits and other circuit within the system. Because the RS-232 interface circuit input voltage is 5V to 25V, between VCC is likely higher than the supply voltage 9V, exceeds the maximum area burned circuit. ESD protection circuit is the most effective protection measures is medium isolation: dielectric to internal circuit and isolated from the outside world. 1mm thick of ordinary plastic PVC, polyester or ABS 8KV protection ESD. But the actual media without gaps and joints, so materials creep and clearance distance is very important. LCD display screen, touch screen, has a very thick corners (12mm) isolation internal circuits.

ESD protection for the second method is a shield to prevent large ESD to storm the internal circuit. ESD shock metal shielding enclosures, initiallyA few milliseconds rather than protective ground voltage higher than many, shielding enclosures voltage ESD charge as the decline of the transfer, so the first few milliseconds on internal circuits secondary ESD shock, so only use external shield is not enough, the internal circuits and shielding enclosures must be shared, or the internal circuit for medium isolation. Electrical isolation also inhibits the ESD shock of an effective method, PCB mounting optical coupler or transformer, although it is not possible to completely eliminate the impact of the ESD, but combined with medium isolation and shielding can be very good on EDS, optical coupler and the transformer is particularly suitable for the power part. Signaling the best isolation is fibre, wireless, and infrared.

In the signal path on the use of another kind of protection is in each signal line plus RC components. Series resistor to limit the rush current, parallel to the sides of the capacitor can limit instantaneous peak voltage. This low cost, but limited defensive capabilities. ESD damage to a certain degree of restraint, but still exist. Since RC-component and cannot reduce peak voltage peak value, simply reduce the slope of the voltage to rise. But RC components also causes a distortion that limits the length of the communications cable and communication speed. External resistor/capacitor has also increased the circuit board area. Another popular method is applied voltage transient suppressor or TransZorb diode. This protection is very effective. There are some disadvantages: plus devices will increase the circuit board area; protective device capacitance effects will increase the signal line equivalent capacitance; cost is relatively high. Adopt internal integrated ESD protection function of serial interface device is an effective way. This type of diodes than ordinary non-protection function of the device's price is higher, but additional costs compared to the cost of additional protection against diodes. Internal ESD protection circuit integrated will not increase any input and output pins of equivalent capacitance, saving boardspace. Maxim company in recent years the development of an integrated ESD protection technology that provides a full range of ESD protection devices, including serial interface and the standard device is fully compatible with the product. Maxim also apply the same technology applied to the emulation switch and switch to shake the product. All of these devices of ESD protection ability meet ± 15kVIEC1000-4-2 (air gap discharge), ± 8kVIEC1000-4-2 (contact discharge), ± 15kV human body model (HBM) test standards.

Maxim's ESD protection of the European Community as provided for in the ESD protection have rigorous testing standards: ± 15kVESD human body model tests; ± 8kVESDIEC1000-4-2 contact discharge mode testing standards; ± 15kVESDIEC1000-4-2 air gap discharge mode testing standards; ± 4kVESDIEC1000-4-4 electrical fast transient/burst mode test standards. Of these, IEC1000-4-2 and ± 15kV human body model test standard primary difference between peak current; the same voltage IEC1000-4-2 shock absorption and current than the human body model, delivering up to five times more. ± 4kVESDIEC1000-4-4 electrical fast transient/burst mode test standard is simulating switch and relay the results of arc discharge. MAXIM devices can provide protection: ± 4kV twice IEC1000-4-4 standard ± 2kV pointer.

Because each device ESD threshold is different, each device in the normal working condition, off-State and powered by ESD threshold, so the Maxim we strictly follow the following steps to test:
1. starting from ± 200V, every increase in the 500V on each device that the impact of different polarity of the voltage and. 2, each time after impact, check the supply current to ensure that the devices have no atresia, check the transmitter and receiver is working properly;
3. repeat the above steps, until the device is damaged or meet ESD testers restrictions;
4. use the human body, IEC1000-4-2 contact discharge, IEC1000-4-2 air-gap discharge and IEC1000-4-4 fast/transient/pulse repeat these steps;
5, respectively, in the normal working condition, off-State and powered by repeating the test. Assurance reaching ESD protection testing standards, and not occurring by alternating and reverse driver problems.

Weak current College】 【soldering of basic skills and tutorial】.

<br> <br> Soldering iron temperature reference: 20W460 <br> 35W560 <br> 50W580 <br> 80W650 <br> (For room temperature maximum temperature) <br> Another constant or constant temperature soldering iron maximum temperature generally set value lower .than conventional soldering iron. <br> <br> Electric iron is electronic circuit welding tool most commonly used to convert the energy of heat energy to carry out the welding point position, whether it is heated by soldering a large part of success is to look .for it in # how are controlled, so in some ways, the use of electric iron on a tactic. <br> In General, electric iron, the greater the power, the greater the heat soldering iron temperature is higher. General transistors, integrated .circuits, electronic components soldered to choose inner heat-20W soldering sufficient power for over-size easily burn component, because the diode, triode junction temperature exceeds 200 ℃ will burn out. But to scaffolding welding-danji production, electric iron power to bigger, .you can choose the 35W-45W even greater. <br> It is worth noting that line welding, time not too long or too short, too long or easily damaged, and the time too short solder cannot fully melted, resulting in a smooth and .firm solder joints are not, you may generate virtual welding, generally the most appropriate time must be completed within a 1.5s ~ 4s. <br> Solder is a fusible metal, most commonly used are generally the solder wire. Solder's role is to make .the symbol pin and printed circuit board connection points to connect with the solder on the welding quality is greatly affected. Now the most commonly used generally contain Rosin solder wire, but it also has broken down, which really is not mixed with water containing silver solder .wire of course are commodities. <br> Also worth mentioning is the absorption, it is very useful for novice, first use the solder soldering always easy to get all that absorb that it can help you put on the Board to dispose of excess solder. .In addition, absorb for removed many feet in the circuit is very effective and useful, it can be all suck off the solder joints, and be familiar with the use of a soldering iron is completely unnecessary, using soldering iron completely replace its functionality, the .solder joint melted away you can easily remove the component. <br> Before welding, symbol pin or circuit board welding parts for welding pre-treatment. <br> Clear the welded joints of oxide layers - available broken saw blade into the knife, .scrape the surface of metallic lead oxide layer, so that the PIN reveal metallic luster. Printed circuit board available spinning paper after the Polish copper foil, apply a layer of rosin alcohol solution. <br> Symbol Tin ---- blowing NET on tinned .wire. May lead to dip the Rosin alcohol solution will bring the Hot Tin soldering iron pressure in inlet and turn the leader. You can make the leader evenly coated with a layer is a thin layer of Tin. Welding wire, insulated before peeling off, .and then after the above two processing, welding can be formal. If stranded wire wire, backlit after you screwed together, then Tin. <br> Good welding pre-treatment, you can carry out welding: <br> (1) right hand .holding the electric iron. Left hand with a sharp nose pliers or tweezers clamping components or wires. Welding, soldering to preheat. Tip-Edge surface to eat Tin, with a certain amount of solder. <br> (2) the occurrence of the .blade surface close to the spot. Electric iron and the horizontal angle of 60 ° c for approximately 10%. For molten Tin solder from the occurrence of the upper class to. Tip in the solder joint Department stays control in 2 to 3 seconds. < .br> (3) carrying out soldering iron. Left hand is still holding symbol is not moving. Question of Tin solder joint office cooling and solidification before releasing the left hand. <br> (4) with tweezers, turning the leader, and then .verify that no loose available side cutting pliers to cut off excess wire. <br> Welding quality-welding, to ensure that each firm, contact welding good. To ensure that the welding quality typical characteristics is the point of light, sleek Tin without burrs ., Tin content is acceptable. Tin and was welded from integration firm, should not have the virtual welding and pseudo welding. <br> Virtual welding is solder joint Department of the small amount of soldering, resulting in poor contact, when broken when you pass .. Fake welding refers to the surface like welding, but there is no welding, sometimes a drawing by hand, lead to unplug from the solder joint. <br> Welding circuit board, be sure to control time. Too long, the Board will be .burned, or cause a copper abscission. Remove from the circuit board components, electric iron head attached to solder, Tin solder stay melting on the component. <br> How to remove the heat exchanger components ------ Mtbr component and then .actually simple, using suction welding is very easily accomplished, a component pins on solder all suck off, tell everyone a little know-how, now most of the fine workmanship of circuit boards, the solder used rarely, it is difficult to melt away, .so we can add some solder on the PIN to use suction welding is much easier. <br> Another method that is mentioned earlier, the direct use of electric iron melting away the solder, but this is no small danger exists, it is necessary to .carefully solder joint didn't completely melted away, but fear of contact for too long or else the component. Commonly used method is to use heating when pulling pliers component, when the temperature is reached, the component will be pulled out, but keep in .mind that not too hard, otherwise broken solder PIN is in trouble. <br> Of course, to be on the safe side, combining the two methods is to use couldn't have been better, because sometimes due to component jacks is too small ., suction welding are hard to clean, remove absorption absorption will stick welding apparatus, electric iron heating can be used to remove. <br> Welding does not so terrible, perhaps to the uninitiated, the initial comparison difficult to grasp, but much also practiced .naturally skilled. In short, for the enthusiasts enjoy hands-on, as long as you practice more then grasp the trick is sooner or later. <br> <br> <br> <br> <br> <br> <br>.

Weak current College】 【Electrolytic Capacitor filter method】.

Electrolytic Capacitor is one of the electronic industry is more difficult to control the quality of components, caused by the electrolytic capacitor products quality problem, many manufacturers do not know how to check the quality of the electrolytic capacitors, had to buy name brand electrolytic capacitors, which would raise a lot of costs. I go through exploration and practice, take out of a set of efficient non-conventional screening methods and homemade clamp introduced to everyone, regardless of brand, brand or counterfeit, a discussion will know the quality is good or bad. Conventional test methods regular e-book has to repeat instructions in this article. In addition, I am proud that I used in electrolytic capacitor vendors also asks me to do a few set for their own products and competitor comparison of product quality.

Principle: electronic ballasts used in electrolytic capacitor main question is when the work is not enough pressure values or poor temperature coefficient, resulting in electrolytic capacitor is damaged. This method is the ultimate in electrolytic capacitor of work pressure, through the charging and discharging to detect Electrolytic Capacitor quality, if conditions at high temperatures to do filtering. If not enough performance Electrolytic Capacitor, a little leakage, other electrolytic capacitors stored charge will be through emitting the capacitance, the results will be poorly capacitive blow up. Performance of electrolytic capacitor intact

The main components are selected: T1 with 0-250V/1KW of Lotus root pressure regulator, T2 need customized parameters is 500W, 220/380V bootstrap isolation transformer. 1000V DC voltmeter with quanta. S1 and S2 switch with linkage, it is best to choose the machine's emergency brake switch instead. Bulb lamps with ordinary Dahurian angelica. Fuse with a fuse of delay on TV.

Production method: first make a fixture, you can put many test. Electrolytic Capacitor pin fixation and reliable electrical connections. Then use a box, all the things installed in the trunk, voltage meter, light bulbs, switches, and regulating the handle mounted on the outer surface of the box, plug in the electrical circuit to a Electrolytic Capacitor filter.

Equipment debugging method: first, in accordance with the requirements of the electrolytic capacitor tuned operating voltage, Electrolytic Capacitor mounted fixture clamp, close the lid of the box, press the power switch, the lamp lights up, while the pointer is on the rise voltmeter, indicating circuit giving Electrolytic Capacitor charging to the voltage, the lamp is off. Then the rotary switch to switch jumps when the light bulb lights up, indicating that the electrolytic capacitors in discharge and voltmeter pointer in decline. This indicates that the apparatus is working properly.

Rated working voltage selection method: in General, the rated operating voltage selection for Electrolytic Capacitor ID voltage of 110-120%, such as identity voltage 400V, then the voltage selected as 440-480V. If the instrument in high temperature conditions on selected as 440V, in low temperature conditions on selected as 480V.
Filter action: under the identity of the electrolytic capacitor tuned operating voltage, the turn off the power switch on the electrolytic capacitors, clamping, covered with lid. Turn on the power switch is turned off, repeated three times, then turn the power switch, maintaining a half an hour, then repeated three times, and finally switch off the power switch, remove the electrolytic capacitors, this step filtering work is complete.

Note: If during the testing process of the bombing, rupture, leakage of electrolytic capacitors are unqualified, the other can be used as qualified for use.
Comprehensive screening method also contains the capacitance, leakage currents and loss angle detection.

Weak current College】 【interpretation of Chinese flat panel TV energy efficiency standard】.

<br> <br> Recently, confirmed our flat-panel TV energy efficiency standard will be December 2010 officially implemented on January 1, this means that there will be the subject of energy efficiency has not been affixed flat-panel TV will be listed. .In order to let users have on the imminent implementation of energy efficiency standards have a clue, I am happy today, it is a simple resolution. <br> <br> · China's latest release of the flat panel television limited values of energy efficiency rating .of standard <br> <br> China's latest GB24850-2010 the flat panel television limited values of energy efficiency rating for the part of the terms of the mandatory national standards, national development and Reform Commission resource conservation and environmental protection division and the standards Council .of proposing an industrial standard, the national energy Foundation and centralized management Standardization Technical Committee, the main leading, National Institute of standardization production enterprises and institutions to participate in the formulation. <br> <br> The flat panel television limited values of energy efficiency .rating of standard was completed in June 2009, the approval form for approval of the draft 2009-the end of the WTO website publicity. <br> <br> 2010 Jan release, 1 December took effect. <br> <br> China flat .panel TV energy efficiency labeling <br> <br> Flat panel TV energy efficiency standard status <br> <br> In the global market, in addition to China will soon implement energy efficiency standards for flat-panel TV also has four energy-saving .specification, namely the United States of the EU's EnergyStar, EuP directive, Japan and Australia for TopRunner energy-efficient labelling MEPS. <br> <br> 1, United States of EnergyStar <br> <br> <br> United States of " .Energy Star "<br> <br> ENERGYSTAR logo believe many of my friends have seen, it is the United States environmental protection agency-initiated an energy savings plan. ENERGYSTAR since 1992, is aimed at reducing energy consumption through energy-saving products to .help people save money and protect the Earth's atmosphere, in the United States and Canada on many household appliances are stuck to it. Internally it is translated as "Energy Star". <br> <br> 2 EUP directive, European Union <br> .<br> The EU environmental directive EUP is the WEEE and RoHS directives, the EU is another major barrier for energy technology - directive "energy products" eco-design of the framework directive (EUP directive). <br> <br> For the .first time, the directive will introduce a product life cycle concept design, to its source, in product design, manufacture, use, maintenance, recovery, post-processing this cycle, on energy products to the requirements of environmental protection, Omni-directional monitoring .products on the environment, reduction of environmental damage. <br> <br> 3, Japan's TopRunner <br> <br> Japan's TopRunner (leader) system is based on energy efficiency best product of the values for the basic goals of the standard values ., you must achieve the same objective standard value of the product is divided into the same class, and according to product and technological progress constantly revised standard values. According to the energy conservation law, the manufacturer must comply with the standards, or be affected warnings ., notices, orders and fines (100 million yen), and other penalties. <br> <br> 4. energy saving label MEPS Australia <br> <br> 1999 Australia implementation of the national energy efficiency labeling system. In addition, in .Australia market belongs to the energy efficiency of products in the control directory, apart from the need to add energy efficiency labeling, some products also have to meet stringent performance criteria for minimum efficiency (MEPS). <br> <br> · China flat panel .TV energy efficiency standards of the 4 major features <br> <br> Standard feature: brightness and power consumption trade-off between <br> <br> Proposed include brightness and power factors of "energy efficiency index" as the evaluation parameters, to .visually reflect the flat TV electro-optical conversion efficiency. Select the brightness parameter and the balance between power consumption, more conducive to the promotion of energy-saving technology and universal, thereby promoting a smooth flat TV industry in China, health development. <br .> <br> Standard features of different products with independent evaluation system <br> <br> Standard product range includes both the LCD and plasma flat panel TV display mode. Standard fully into LCD TV and plasma TV to their technical characteristics, the differential treatment .of two completely different technology system, in a spirit of respect for differences, the principle of fair treatment in the unified testing method, namely evaluation LCD TV and plasma TV energy efficiency index. <br> <br> Standard evaluation method of evolution: < .br> <br> Consumed power → energy efficiency (Eff) → energy efficiency index (EEI) → EEI (LCD) <br> → EEI (PPD) <br> <br> Standard feature: test prototype work state expressly provided <br .> <br> Work status of the current industry-wide application of flat-panel TV test standard SJ/T11348 the digital TV flat panel display measurements ". By adjusting the brightness and contrast, adjust the display to be accurate performance-enhanced levels of .status (and that this State is relatively unique), that is, the normal working condition. The setting and our flat-panel TV industry standards to ensure that energy efficiency test and performance test status are the same, without loss of performance on the basis .of the principle of improving energy efficiency. At the same time, the test status clearly can ensure that each of the same type of flat-panel TV product energy efficiency index is placed in an open and fair platform compared to visually reflect the product at the .level of energy-saving aspects of technology. <br> <br> Standard features four: explicitly set on the measurement status output luminance limitation <br> <br> In order to prevent the use of excessive increase brightness to enhance the energy efficiency index .of standards with the introduction of the brightness parameterNumber at the same time, explicitly set the brightness of the measurement status output, so that test status of brightness is not higher than 350cd/m2. Brightness limits can boot industry in ensuring reasonable brightness output, lower .power consumption, improve energy utilization. <br> <br> · China flat panel TV energy efficiency standards for content <br> <br> 1. terms and definitions <br> <br> 1. flat-panel TV energy efficiency index < .br> <br> The provisions of this standard measurement method, flat-panel TV energy efficiency measurement and reference value. "Energy efficiency index. <br> <br> Energy efficiency: <br> <br> This standard specifies test procedures, .flat TV screen's luminous intensity and flat-panel TV energy consumption (power-on status and signal processing power of the poor) ratio, and the candela per watt (CD / W). "Energy efficiency" physical meaning refers to the screen by up .unit solid angle of the light flux and the ratio of energy consumption, ie flat panel TV per watt electric energy is converted to normal luminous flux of efficiency. <br> <br> 2. passive standby power <br> <br> The provisions .of this standard measurement method, flat-panel TV in passive standby measured active power, expressed in Watts (W). <br> <br> 3. turn on power <br> <br> The provisions of this standard measurement method, flat .-panel TV at power-on State measure active power, expressed in Watts (W). <br> <br> 4, the minimum allowable values of flat panel TV <br> <br> The provisions of this standard measurement method, flat .-panel TV the allowed minimum efficiency index and maximum passive standby power. <br> <br> 5. evaluating values of energy conservation of flat panel TV <br> <br> The provisions of this standard method of measurement, energy-saving flat .panel TV the allowed minimum efficiency index and maximum passive standby power <br> Rate. <br> <br> Second, flat-panel TV energy efficiency ratings <br> <br> Flat panel television energy efficiency rankings level 3, one of the .highest level of energy efficiency. Energy efficiency index of all levels flat panel TV should follow GB/T8170 related provisions for rounding off two significant digits, this rounding off values should not be less than provided for in table 1. <br> <br> .<br> <br> · The minimum allowable values of flat panel TV <br> <br> Flat panel TV minimum allowable values of the required minimum efficiency index for energy efficiency rating of level 3. <br> <br> Use external power .supply of flat panel TV, external power supply used should be consistent with the minimum allowable values in GB20943. <br> <br> · Evaluating values of energy conservation of flat panel TV <br> <br> Flat panel TV evaluating values of energy .conservation for the required minimum efficiency index for the level 2 energy efficiency rating. <br> <br> Use external power supply of flat panel TV, external power supply used should be consistent with GB20943 in evaluating values of energy conservation. <br> < .br> · Flat-panel TV passive standby power limit value <br> <br> Flat panel TV passive standby power shall be measured as per GB/T8170 related provisions for rounding off two significant digits, rounding off values should correspond to the following table .. <br> <br> <br> 3. flat panel TV calculation of the energy efficiency index <br> <br> · LCD television energy efficiency index is calculated as below: <br> <br> <br> <br> .Type: <br> <br> Eff - flat-panel TV energy efficiency unit candela per watt (cd / W); <br> <br> L - the average brightness of the screen, expressed in candelas per square meter (cd / .m2); <br> <br> S-effective light-emitting screen area, in square metres (m2); <br> <br> Pk-power-power, expressed in Watts (W); <br> <br> .PS-signal processing power, expressed in Watts (W). Use the YPBPR component interface input PS from 6W; use analog RF interface input PS from 10W; use digital RF interface input, PS for 17W. <br> <br> · LCD .television energy efficiency index according to the below formula: <br> <br> <br> <br> Type: <br> <br> EEILCD-LCD television energy efficiency index, dimensionless; <br> <br> EffLCD, ref: .LCD television energy efficiency reference value, equal to 1.10cd / W. <br> <br> · Plasma TV energy efficiency indices are calculated below <br> <br> <br> <br> Type: <br> <br> EEIPDP .-plasma TV energy efficiency index, dimensionless; <br> <br> EffPDP, ref-plasma TV energy efficiency reference values, the values in the table below: <br> <br> <br> <br> Currently, consumers buy flat .-panel TV in asking energy, health, environmental protection and other aspects, a significant increase in the proportion of, energy saving and environmental protection has become flat panel TV and buy one of important indicators. China flat panel TV after the implementation of energy efficiency .standards, consumers can purchase refrigerators, air conditioning and, through the post of energy-efficiency standards can be compared easily at a glance of the purchase of high-efficiency flat panel TV. <br> <br> <br> <br> < .br> <br>.

Wednesday, January 26, 2011

【 Weak current College 】 compressor maintenance system 】

Summary: on a Web-based remote maintenance service of the compressor and explains the current situation; in the compressor maintenance involves various links study established a system of operating modes; combined with the actual project to research and design of the compressor remote maintenance service of software and hardware, in Assembly language and C language to establish mixed programming scene online signal Gets a compressor system and LabVIEW in, offline signal analysis and processing virtual instrument system; the use of TCP and UDP protocols to Winsock programming establish internal maintenance decision support system server; use Interact resources to remote compressor producers side-b/s model remote service system; research proves that the system has good usability;

Keywords: compressors, compressor maintenance; repair; networks; along with the development of industrial technology, large compressor large, automation, information technology and electrical system integration direction. To do this on the compressor for management, maintenance and troubleshooting proposed update higher requirements. Compressor structure and fault complexity is a business-to-repair by intelligent, scientific basis. And good maintenance to ensure the safe operation of the compressor. Network-based remote medical diagnosis system for the last few years developing very fast ¨ J. The device troubleshooting and network together is remote diagnosis, research in this field is attracting more attention, such as the United States of Westinghouse, Bentley, and Stanford University, Massachusetts Institute of technology, research and development of a network-based remote diagnostic system. Domestic universities and research institutions in carrying out this research, the development of the system's purpose is to complete the device field data and all relevant departments, by joining the network more synchronization troubleshooting.
Network technology development to the compressor provides remote maintenance service. Compressor "remote maintenance service" is a Web-based, remote diagnosis, maintenance plan, maintenance management and decision-making, production and management of spare parts, maintenance, repair, inspection and other related support technology. Through computer networks will reflect the compressor site health data, design, manufacturing and processing of the original data, information, scientific research departments and institutions of the theoretical and experimental research, installation companies and similar compressor in the different units of the use of information and other information in combination with the high efficiency, quick launch and maintenance of a maintenance mode. Let the different regions, different departments of the "experts" through the network and remote data for device management, truly "movement" is the data rather than people. Let compressor maintenance first in virtual environments, to shorten the repair time, reduce costs, increase productivity, improve design, manufacture, installation, use of technology and technological level has crucial value. Let the production equipment is also an experimental research, "" device. Is to achieve "green maintenance" of an important means. Future maintenance will not only is the enterprise's internal affairs, but is more departments involved in the production activities is maintenance of socialization and networking; with the help of specialized "maintenance service Web site," will be the enterprises to develop effective ways of maintenance. Web-based maintenance management system and other MIS integration, intelligent decision support systems will be a maintenance service system development direction.
1 network-based compressor maintenance service system mode compressor design, production, installation and use of each link data and information are in repair, and may be used to play an important role. If to set up remote repair service network, the system is very complex, it requires that each link is necessary to establish appropriate information acquisition and processing system, in fact compressor production mode is set to a certain links to complete. The simplest is integrated by Figure 1 a typical pattern. Integrated streamlined form a product of producers and users. This makes maintenance service system to simplify, we only need to establish a producer and user of the online service system. In this model, users establish equipment data collection, information processing systems and maintenance service internal decision-making system, the device's operating data (run the dynamic parameter value and related chart) according to the specification for storage,
Compressed data transfer over the network to the producers ' side. Producer-need to establish a maintenance service system, to provide relevant information for the user to browse and access to technical support. Producer-in access to client data after the data into the
Line processing, transformation, recognition. Make diagnosis conclusions and maintenance service responses, such as through the data to determine the status of the device, if any exception or failure to make the cause of the failure, the nature, location, and the possible consequences of remaining life, maintenance and technical support to decision-making. And the results back to the client access to and use of this information, to share information Internet interaction. Further agreement with the user arrange spare parts production, can also be virtual environment simulation service. At the same time producers-end use of the data and information, in turn, guide product development, design, production, and further improve the level of service in the future.
2 user-end online monitoring system
Compressor run data acquisition and real time processing system: the user has established in order to run parameters, such as flow rate, pressure, temperature, speed, vibration displacement, velocity, acceleration, stator current, voltage, and oil, and other multi-channel signal acquisition and processing system, the current number of existing equipment on reconstruction, development should be conducted by the product development department comprehensive consideration in the design and highly integrated, modular and reliability. (Figure 2) is an enterprise through the transformation of on-line monitoring system block diagram. The entire equipment distribution in more recent location, shielded cable transmission, the use of fieldbus RS232 signal acquisition system; used with multi-channel interface screen composition data mining
Set network. Complete real-time monitoring, overrun alarm, online diagnosis and offline analysis and corresponding data management. The system can be extended to more than one device monitoring, control and diagnosis.
3. the user-end compressor maintenance management services system for users in the maintenance process, the first is to use its own rapid reaction informationProcessing and decision-making system. Mobile Office Device Management Center for this purpose the establishment of first-level management and decision-making functions, to engineering
College Station, as shown in Figure 3. Systems and services to the distance between objects in a few km range, the establishment of IOM/IOOM Ethemet and hubs (Hub) to establish a network connection to the scene. Use of field data, manage records, information, maintenance recommendations, spare parts etc. make diagnosis and maintenance decisions. And according to the production plan, approved by the competent Director for maintenance planning and execution. Client Management Centre engineers stand for: server, complete the listening clients (client-side) of the connection request, the client connection requests to establish Socket queue processing client data sent to and send a response. To TCP and UDP protocols through Winsock programming build server; the use of two-way connection of the TCP protocol to create a server, setting up two Winsock controls, one uses the TCP protocol to listen in order to build a browser on the client's connection and transfer HTML pages and another uses the UDP protocol is used to keep the client connection transfer real-time monitoring data compressor. Client: complete and close the connection to the server, sending data to and receive data from the server, you will receive the data on your own database for the relevant personnel (sector) to access, view. Related departments through IE browser to access the compressor site HTI'P agreement, compressor site will send the HTML page through the server to the visitor, and browser clients stay connected, you can observe the compressor running time.
Browser client can remotely view stored in the monitoring system database host parameters, and the server connection is established, the browser client can use different means such as data tables, trend graphs, spectrum graph, see running cited.
4 Web-based remote diagnosis and maintenance service support system compressor producers-the user-supplied data, you must respond and concluding observations. Producer-end should be established its internal information processing network. Figure 4-compressor producers remotely repair services to support the decision-making system. The system involves user distance may very far, so you can only use Internet resources or wide area network. Producers from the various user-side access to data and information usage and maintenance. Combined with producers in the design, development, production, processing, and other aspects of the experience and lessons learned, while leveraging other research results or seek the advice of "experts" in the field of the user-side maintenance decision made by reassessed. This system has 3 modes of operation, 1) using Synchronization Network Conference: according to a user's request, the system get sixty experts from various sectors, onthe collected data for consultation-solution. 2) "letter Exchange mode": the client through the Internet send requests to a remote server, and will be issued along with the related data; the associated system reacts in a different time, then use the same letter the conclusions to the requester. 3) direct user login server, use Dialogic expert system for remote diagnosis and maintenance services. Network-based distributed applications can be as simple and effective implementation of off-site remote multi-user service, system development environment and application isolation environment, and development process and application process can be relatively independent asynchronous, the browser as a public uniform standards for common user interface (CUI) environment for easy system management and upgrades. Network programming using b/s structure, the benefit is that the browser client only needs standard configuration of the operating system, without having to install any software and other applications, saving both the browser client system resources, enhances network openness and compatibility, also facilitates management's use. Based on b/s system can be easily integrated with many additional features, such as E-mail, BBS, Net chat, etc. So you can easily construct a offsite remote consultation and collaboration between man and machine working environment, in the device's remote maintenance service better application.
5. concluding remarks
Research has shown that for like compressor such large equipment for remote maintenance service system is necessary also is possible; the device running the underlying field data and various functional departments within the enterprise, complete network-based data acquisition and processing and realization of internal maintenance service for decision support; with the help of the Internet, each with enterprise data, decision making and design, manufacture, installation, and the "third-party expert" into the
Line connection,remote diagnosis and maintenance decision support services, these system and function implementation is an important area of Web application. Network application will run through the enterprise production, network access to maintenance is also an inevitable trend. Currently, the enterprise has launched a Web-based service, but less functionality, integration and interactivity, the effect is not evident. Network-based remote diagnosis and maintenance decision support system is a network technology and modern diagnostic technology and repair techniques, combined with the inevitable outcome of a future device management objectives pursued by; Web-based remote maintenance decision support system will become an enterprise device management modernization
Key technologies.