Tuesday, February 22, 2011

Weak current College】 【Green environmental protection activities in the cold room】.

<br> Under the Montreal Protocol, currently in the refrigeration system in the widespread use of freon refrigerants, due to the atmospheric ozone layer damage, will be banned. (For CFC refrigerants, 2010 deactivate, developed countries have in the end of 1995; .for HCFC refrigerants, developing the latest in 2040. Now the new active cold storage) system using new environmentally friendly refrigerant, launched the series green cold storage: <br style="mso-special-character: line-break"> <br style .= "mso-special-character: line-break"> <? xml: namespace prefix = "o" ns = "urn: schemas-microsoft-com: office: office"?> <o:p> </ o: p .> <b style="mso-bidi-font-weight: normal"> Environmental protection activities in addition to the smell of cold storage air purification: <b style="mso-bidi-font-weight: normal"> <br style .= "mso-special-character: line-break"> <br style="mso-special-character: line-break"> <o:p> </ o: p> Green environmental protection activities in addition to the use of .new electronic refrigerator smell unit, high pressure discharge air ozone generation so that it is in the unusual smell composition (sulphides) chemical reaction, the odor elimination, inhibit microbial growth within the library, and maintain inventory of food hygiene. The device in addition to .the smell of efficiency up to 95 percent, the need for manual operation and long life. <o:p> </ o: p> <o:p> </ o: p> Cold storage <b style = "mso-bidi .-font-weight: normal "> environmental activities: <o:p> </ o: p> supporting the diversification of <o:p> </ o: p> environmental activities select freezer insulation: thermal insulation core have diversity polyurethane and .polystyrene. Panel materials FRP, color-steel, stainless steel, embossed aluminum plate, etc.; the Green environmental protection activity diversification refrigeration host selection: you can choose to import or domestic refrigeration compressors of different brand; cold storage uses diverse: there are .temperature <? xml: namespace prefix = "st1" ns = "urn: schemas-microsoft-com: office: smarttags"?> 0 ° c to <st1: chmetcnv w: st = "on" tcsc = "0" numbertype = ."1" negative = "False" hasspace = "False" sourcevalue = "15" unitname = "℃"> 15 ° c </ st1: chmetcnv> preservation library, the low temperature cold (temperatures from <st1: chmetcnv w: st .= "on" tcsc = "0" numbertype = "1" negative = "True" hasspace = "False" sourcevalue = "28" unitname = "℃"> -28 ° c </ st1: chmetcnv> to <st1: chmetcnv .w: st = "on" tcsc = "0" numbertype = "1" negative = "True" hasspace = "False" sourcevalue = "18" unitname = "℃"> -18 ° c </ st1: chmetcnv>) or .with both temperature-one double warm cold storage. <br style="mso-special-character: line-break"> <br style="mso-special-character: line-break"> <o:p> </ o .: p> <b style="mso-bidi-font-weight: normal"> Environmental protection activities in the freezer for intelligent control system: <br style="mso-special-character: line-break"> <br style = ."mso-special-character: line-break"> <o:p> </ o: p> Active cold mcrocumputer automatic control cabinets, cold storage daily run of automatic control. <br style = "mso-special-character: line .-break "> <br style="mso-special-character: line-break"> <o:p> </ o: p> <b style="mso-bidi-font-weight: normal"> Environmental protection activities .in the cold store advanced optimization reasonable configuration system: <br style="mso-special-character: line-break"> <br style="mso-special-character: line-break"> <o:p> </ o .: p> Activities in the refrigeration systems of reasonable match, in the performance of the play a vital role to play. After years of engineering practice, using the best system matching the refrigeration equipment achieve the best cooling capacity and the best performance. <br .st> </ br st> </ b> </ b> </ b> </ b> </ b> yle = "mso-special-character: line-break"> <br style = "mso-special- .character: line-break "> <o:p> </ o: p> <b style="mso-bidi-font-weight: normal"> Compared with ordinary cold storage systems, green environmental protection activities in the cold store has .the following characteristics: <b style="mso-bidi-font-weight: normal"> <br> 1, environmental protection, in addition to smell antibacterial, energy saving, low operating cost; <br> 2. run a reliable, .no maintenance headaches, refrigeration and low noise; <br> 3. the use of high-efficiency air cooling or water-cooled condensers product; <br> 4, diversification of the radiator to choose from (with plate-fin type, etc. .); <br> 5, refrigerant, refrigerant selection diversity (ammonia, and freon, propane, etc .).</ b> </ b>.

【 Weak current College 】 combined refrigerator basic design requirements 】

Cold storage design step one: cold storage library site selection and prepared by using properties, cold storage room can be divided into distribution of cold storage, retail of cold storage, productive cold storage. Production of refrigerated warehouse built in sourcing more focused areas, but also the transportation is convenient, and market linkages, and other factors. Cold storage room to build in the absence of sunlight and shade on hot air frequent, small freezer best built indoors. Cold storage around the expected good drainage conditions, groundwater level to low, it is best to have cold storage underneath, and insulating layers remain a well-ventilated, dry on the cold store is important. Also in the cold store construction in accordance with the erection of power prior refrigerator appropriate capacity for three-phase electricity, if the freezer is a water cooler, water pipe laying a good, good cooling tower built. Cold storage design of the second step: cold storage warehouse capacity of cold storage size according to the perennial to storage of agricultural products of the highest amount to design. This capacity is based on the storage of products in the refrigerated warehouse stacked in occupies volume required, plus the Interlinear walkway, heap and walls, the space between the ceiling and the packaging that the gap between calculated and so on. Determine the capacity of cold storage, and then determine the length and height of the cold store. Cold storage design time to consider the necessary subsidiary buildings and facilities, such as workstations, packaging finishing room, tools, libraries and loading platform, etc. Cold storage design step 3: cold storage insulation material selection and installation of cold storage insulation material selection must be suited to local conditions, it is necessary to have good insulation properties, and also economical. A cold-insulation material is divided into several types, one is processed into a fixed shape and size of the plate, there is a fixed length, width and thickness, according to the needs of the library of the installation, select the appropriate size of the Library Board, high, medium-temperature refrigerated warehouse General selection 10 cm thick of Library Board, low temperature cold and freezing cold-like selection of 12 cm or 15 cm thick of library board; another cold storage can use polyurethane spray foam sprayed directly on the materials to the construction of brick or concrete cold storage warehouse, shaped and insulation after both moisture-proof. Thermal insulation with polyurethane and polystyrene resin, etc. Polyurethane non-absorbent, insulation of good, but cost more; polystyrene fat absorption, heat less, but is less expensive. The structure of modern cold storage to the assembled cold storage development, made of moisture-proof coating and included insulation layer of cold store Widget, do on-site Assembly, its advantages are easy, fast, and portable, but the cost is relatively high. Cold storage design step four: select freezer refrigerator cooling system of the cooling system of choice for mainly freezer compressor and evaporator selection. In General, a small selection of hermetic compressor refrigerator. As a result of hermetic compressor power small, relatively cheap; medium cold storage selection semi-enclosed compressor mainly in general; large selection semi-enclosed compressor refrigeration storage, use, or you can consider the ammonia refrigeration compressor, because ammonia refrigeration compressor power and multi-purpose a machine, but cold storage installation and management more cumbersome. Selection of the evaporator, the heat cold store to use air cooler for the evaporator, which is characterized by rapid cooling, but the readily lead to moisture loss of refrigerated product; selection of medium and low temperature cold produced by the evaporation of seamless tubes, its characteristics are constant temperature effects, and the timely cool.

Weak current College】 【white energy saving standards implemented two years results are obvious】.

Recently, the official statistics, household refrigerator and air conditioning energy efficiency labeling system from 1 March 2005, formally, the cumulative savings over our 37 billion kWh of electricity, which over the past two years has eliminated the air-conditioning market 31.4% of energy-consuming products. Standard of practice effectively contributed to industry technological progress as well as the industrial upgrading, also contributed to the community include business-to-energy-saving standard of unprecedented attention. "For the enterprise, standard, improving means of raising the threshold of industry, enterprises must take precautions, the product is to introduce more energy-efficient products. "Domestic air-conditioning company official said, but the people recognize the" domestic energy saving, in addition to removing various gags in the misconception, the key is to improve market acceptance. "Energy efficiency standards-intensive introduction of information display, refrigerators and air conditioning in consumption of and about our household electricity supply of 70%, is the large electricity, while at the same time means that the energy-saving potential is great. In June of this year, the State Council issued a comprehensive work-saving emission reduction programme (hereinafter referred to as "the programme") that: "the eleventh five-year plan" period unit GDP energy consumption reduction target of 20%, the programme explicitly required organization system (repair) for power transformers, Xerox, air-condition, commercial freezers, refrigerators etc terminal using products (devices) energy efficiency standards. The reporter was informed from the enterprise, in the national trend of strong energy conservation and emission reduction, air conditioning energy efficiency standards have been revised, 2009 entry level or to upgrade to an existing 2-level standard. Refrigerator new energy efficiency standards have been adopted the national energy Foundation and Management Standardization Technical Committee and in the near future will be reported to the national standardization Management Board, the new standard in freezer energy efficiency indicators have been nearing 1 level A + of + levels in the European Union. In addition to the standard upgrade, a series of new standard also have or will soon introduce. Air conditioning, domestic first inverter air conditioner efficiency standards mandatory local; in Shanghai on the water heater, the beginning of 2007 the residential gas water heater national energy efficiency standards promulgated formally and officially launched in July. For solar water heater, has recently released the Chinese State environmental protection administration also first environmental standards "solar". In addition the reporter was informed that the national standards for energy-efficient household electric oven, the new formulation of the standard will induction cooker product follow the thermal efficiency of divided into five levels. In addition, the national development and resource use and environmental protection, Deputy Director-what ping kwong previously indicated to the media, then there will be more integrated into the implementation of energy efficiency labeling system. Industrialization promotion as key it is understood that, since 1 March 2005 household refrigerator and air conditioning energy efficiency labeling system began operation, product energy efficiency standards have been significantly improved, at present, China's market in the energy-saving power than conventional refrigerators refrigerator 30%, energy-saving air conditioner than ordinary energy-saving 40%. However there are people in the industry told reporters that China's energy efficiency standards for fridges, and advance the work carried out so long, and international level difference is not very large but relatively speaking, the current implementation of air conditioning energy efficiency standards and industry energy efficiency levels remain to be improved. "Standards promulgated after industrialization road is still long. "With air conditioning, for example, the journalists visited stores found that market products sure to entry level four or five-level energy efficiency labeling for air conditioning, and in addition is the level of identity and the identity of third-level air conditioning is very rare. According to the selling field personnel, because the price difference, at thousands of consumers or to purchase four or five levels. To this end, a domestic air-conditioning enterprise that mainly costs, at present, most have air conditioning company that improve energy efficiency standards in 2009, is lower cost technology upgrades. Matsushita air-conditioner is Chinese area General Manager Yang said, "in fact, energy-saving emission reduction is not only to assume social responsibility also has become an enterprise economical support." It is reported that Panasonic has introduced a range of energy-efficient products, in particular the inverter air conditioner can save energy by more than 30%, but he also considered that, since the prices, domestic in inverter air conditioner on capacity remains limited.

【 Weak current College 】 bus non-contact IC card reader application design 】

Summary: use the PHILIPS Mifare card company for IC card, design by RF technology as the core, MCU controller IC card reader on the bus automatic toll collection system. Manufacture of IC card reader can implement system card, card, features such as automatic toll, with safe, practical, convenient, fast, high-reliability features of the urban public transport service is frequent and trivial fees and management issues that have broad application prospects. Keywords: SCM contactless smart card reader and smart card reader overview now often come into contact with IC card has two kinds: contact and contactless IC card. Contact-type IC card through mechanical contact from the reader Gets the energy and the exchange of data; a non-contact IC card through the Induction coil RF from the reader gets energy and Exchange data, also known as RF cards. Currently common in society is the contactless IC card.  It has a storage capacity (in megabytes), the privacy feature strong (there are multiple password settings and authentication functionality), you can implement smart card. However, this type of card read/write operation is slow, is also not convenient, per-read and write, you must put the card correctly inserted into the reader of the estuary trough to complete data exchange so that, in public transport, attendance, and so frequently read and write to the card of occasions is inconvenient, and reader-contact and card IC card touch foot exposed, easily damaged and get dirty and bad. Non-contact IC card is based on radio frequency electromagnetic induction principle. It reads or writes the card in the reader within a certain distance away near to implement data exchange, without any contact, use a very convenient, fast, and not easily damaged. Accordingly, in public transport, access control, campus, enterprises and institutions, such as personnel management, entertainment and other aspects of broad application prospects. At present, China's introduction of RF IC card hasthe PHILIPS corporate Mifare and ATMEL company of Temic card. Following to PHILIPS Mifare card-based company, introduces automatic ticketing urban public transport IC card reader implementation. Second, the principle of non-contact IC card reader/writer for radio frequency identification technology as the core, used primarily in Reader 1 tablet Mifare card dedicated read-write processing chip – MMM micro module. It is a small maximum operation distance up to 20 ~ 30mm of Mifare read/write device for the core components, its features include modulation, demodulate, produce RF signal, security management and collision avoidance system. Internal structure is divided into radio frequency area and interface: RF zone contains the modem and the power supply circuit, connected directly with the antenna; interface areas and MCU port connected with RF area linked to transmit/receive, 16-byte data buffer with, store, transmit key 64 on ROM, store, 3 sets of keys for a write-only memory and three confirmed and data encryption cipher machine, collision with anti-collision module and control unit. This is the RF card for wireless communication of core modules, and also the reader to read and write Mifare card key interface chips. Reader work, unceasingly to issue a set of fixed frequency of electromagnetic waves (13.6MHz), when the card close to the card with a LG series resonant circuit, their frequency and the reader of the same frequency, so that the electromagnetic wave excitation, LG resonant circuit produces resonance, so that there is a charge capacitor charging. At the other end the capacitances, a one-way conductive e pump, the capacitor within the charge to another within the storage capacitor. When the capacitor charging to 2V, this capacitor is used as power for a card for other circuits provide working voltage, the card data launches out or receive data and issued by the reader. III. hardware bus fare system structure more complex, link, public and non-contact IC card readers at least should include public transit vending machine, car and bus transit system card machine three reader. In addition to the vending machine requires keyboard, all hardware components in much the same. Figure 1 is a non-contact IC card and its reader hardware circuit schematics, mainly by MMM micro module, MCU, keyboard, display, memory, antenna and control circuit and PC communication TC232 serial communication interface circuit. (1) single-chip system SCM 89C52. It has within the Tablet 8 KB ROM, 256 bytes of RAM and 32 I/O port. P1 port and serial devices 24C64 and displays, alarm circuit connection; P0 port and MMM-module, used as a data cable; P2 estuary as a 4 × 4 keypad; P3 port is used to read and write control and interrupts. (2) keyboard circuit keyboard interface circuit with P2 port pick up into 4 × 4 structure, a total of 16 key.  Which digital key 10, 2 function keys, backspace and enter each one, there are 2 key temporarily not available.  Function keys with query and communication two keys. Query keys: sale of card member you can use this key query sale card amount and sales card records. Communication: the amount of storage as the reader is limited, so the reader card per sales for a period of time, the data in the reader through the RS-232 serial interface for communication with PC for playback and empty the reader. Data playback to a PC, through the analysis process, forming a variety of reports to bus companies grasp the card sale. (3) display circuit shows part of the digital display, use the serial input BCD code--decimal decoding driven display MC14499 to complete and display interface chip, to show the reader working state, entered data or read the remaining in the IC card as well as error messages, etc. This device mainly 1 20 and displacement-bit registers, 1 latch, 1 multiple output devices. Multi-channel output for output in BCD code decoding by segment decoder, replaced seven yards (abcdefg) and decimal DP to paragraph drive output. (4) memory reader designed storage. Memory selection 24CXX series serial E2PROM. Sales in the main storage card, card number, the sale of card member number, amount, sale sold card card date, sales amount and sales kazong kazong records; in a major repository of on-board machine IC card, passengers, drivers, and credit card number and other information. Displays MC14499 driving 4-Yin digital tube. Normally, each time you want to put the reader to the transit center will reader stored information playback to save PC. The reader can use in memory, its storage 24C64 as 8KB, if necessary you can also use larger memory such as 24C128 or 24C256, etc. (5) monitoring circuit monitoring circuit adopts DS1232L chip. It is a watch dog timer, its function is: when you power on and power-down RESET signal to produce 89C52; watchdog on the system for monitoring, prevention of panic. (6) the non-contact IC card contactless IC card Mifare card selection.  Its operating frequency as 13.6MHz, storage 1 KB-16 zones, each zone 2 set of password, each area of the storage area are independent of each other, so each zone can be used for a purpose (generally 0) for a smart card. Because of the Mifare card password authentication mechanism and strict, saved information relatively reliable security, can be erased tens of times. Mifare card 16 zones, each zone is divided into 4 blocks, each block of 16 bytes. In vending machines with 1 zone for users stored blocks consisting of 0 blocks hold identity number, 1-2 blocks stored value, 3 blocks kept two sets of 6 bytes of the password and a 4-byte read-write access.
IV. programming the following to sales card machine-based presentation software design method. Taking into account the amount of the security sold card management, public transport company prior to making a good two IC ticket: one user IC ticket, and a member of the ticket sale card IC card. The two cards you can use the same area code, password and access conditions completely different, without confusion. Sale of card member you want to sell card requires you to go through a public transport company IC card, ticket sale card. Ticketing IC card memory on the sale of card Member ID number, allows sales to the maximum amount of cards, two sets of 6 bytes of the password and a 4-byte read-write access. Sale of card member sales card, prepaid card must from their ticket sales of IC card card amount subtracted, the IC card added to the user. When selling tickets to minimize the amount of IC card, to zero bus company billing, and then on ticketing IC card prepaid billing. In this way, the bus company's sales card distribution more outlets without chaos, and convenient user charge plus card, you can effectively prevent the ticketing service accounts are not caused by the capital loss. Programs include IC card read-write operation, the keyboard, scanner, display, memory, reading, writing and communications programs. 1. main program master key to complete the system variables of the initialization, circular scanning keyboard detection operation IC card, will the operation result storage and display. In the vending machine uses 8 KB for memory, main 24C64 content stored are: vending machine number (1 byte), sale amount kazong (3 bytes) and total (2 bytes). Sold per card record includes: user card identification number (4 bytes), sale card date (2 bytes), plus card amount (1 byte) and sale of card numbers (1 byte). Therefore the maximum energy storage 1023 Zhang sale card records. The main process as shown in Figure 2, the reader on the IC card operation process as shown in Figure 3. 2. keyboard scanner keyboard scan uses the reverse method reading keys: from P2 port high 4-output zero level, from P2 port low 4 bits read keyboard status; then from the P2 port low 4 bits output zero level, from P2 port high 4-bit read keyboard status, will be the result of two times read together can get the current key signature (see the table in TABLE). This table can be programmed to be converted to order code. With the current read signatures to order look-up table, use a unit record lookups. When in a table to have the signature, it's location (i.e. lookups) is the corresponding sequence code. Corresponding keyboard check key programs are as follows: P2, KEY: MOV; use reverse # 0FH method checks key
MOV P2,#0F0H
RET; no key is pressed
KEY1: MOV A, B; a key is pressed, the key code
MOV R3, # 0FFH; save order code module initialization
CJNE A, B, KEY3; outsourcing key code, please order codes
MOV A, R3; if it finds a key code, order code
KEY3: CJNE A, # 0FFH, KEY2; whether you have contracted for enquiries
RET; also see the key code is not found, no press processing
TABLE: DB 77H, 7BH, 0BBH; press the signature table
DB 0E7H, 0C7H, 0FFH3. display program according to figure 1, in the show circuit, P1-3 root I/O port line (P1.0, P1.1, P1.2) provide clock (CLK), serial data (DA) and enable signal (EN). MC14499 each receive 20-bit serial input data, the first 4 bits for the control of the decimal point of display digital tube, after a 16-bit is 4 digital tube of BCD code input data. In each frame data transfer, you must reset the EN 0; then transfer 20-bit data, data transfer finished, then 1 EN reset. Display program: DISP: CLR P1.0; Qing CLK
CLR P1.2; Qing EN
MOV R2, # 04; reset routing digits
MOV A,# 00
LCALL W14499; count display transfer sent
MOV R1, @ A; read the number to be displayed
MOV R2, # 08; reset routing digits
LCALL W14499
MOV R2, # 08; reset routing digits
LCALL W14499
SETB P1.2; reset EN bit
W14499: SETB P1.0; Qing CLK
RLC A; prepare bitwise sent count displayr>MOV P1.1, C; few moved into DA
CLR P1.0; Qing CLK
DJNZ R2,W14499
RET4. serial E2PROM, reading and writing programs for I2C bus 24C64 E2PROM. SCL-400kHz clock line, SDA is bi-directional data cable, A2, A1, A0 three digits of the selected address, that is, sliced I2C buses up to parallel 8 serial E2PROM chip. On the operation method by E2PROM read/write control command Word decided, as shown in Figure 4. Where "1010" for 4-bit read/write control code, R/W = read/write control bit: "0" for the write operation, "1" for read operations. So combined with Figure 1 shows the A2H is write control command words, read control command A3H. On memory and writing, first of all, the microcontroller to a START command 24C64 fat, start conditions. Then, the write command control word (such as A2H).  When 24C64 received the order, enter a write cycle, and then send the stored by the microcontroller, which determines the address data written to memory in which address, subsequently, the SCM will be stored in data feeds to SDA data line. Write cycle ends, the microcontroller and then issued a stop bit (STOP). Read operations on memory, first of all, the microcontroller to a START command 24C64 fat, start conditions. And then the write command control word (such as A2H). When 24C64 received the order, enter a write cycle, and then send the stored by the SCM. Store addresses sent successfully, the microcontroller to a START command 24C64 fat, start condition, then sends a read command control word (A3H). When 24C64 received the order, enter a read cycle, single-chip from SDA data line reads the specified data is stored in the address. Read cycle ends, the microcontroller and then issued a stop bit (STOP). (A) it is important to note that the memory operation, each read-write a byte, single-chip must send a response bits (ACK) to release the SDA line so that memory can continue to receive data. 5. the communication program in the reader, chip and PC communication is accomplished primarily by TC232 TTL level (0 ~ 5V) and RS232 level (+ 10 ~-10V) conversion (circuit shown in Figure 1), to complete the sale card machine saved sale card record of delivery. Communication format as: serial works 1, baud rate 9600baud, 1 start bit, 8 data bits, 1 stop bit, and validation.  The reader, the MCU program may use the C programming language. C language has a rich library functions, operation speed, compile, high efficiency, portability, and a software readable, easy to improve and expand (program). To increase the adaptability of the transit system, including the user's special requirements, anti-interference, rugged, in addition to the hardware on the use of monitoring circuit, the software also adopted a directive redundant and software traps.

【 Weak current College 】 different working RFID frequency characteristics and typical applications Guide 】

A different band RFID products will have different characteristics of different standards, this article details the passive sensors in different frequency characteristics of the product, as well as the main application.

Currently define the operating frequency RFID products have low frequency, HF and VHF frequency range with different standards of different products and different band RFID products will have different characteristics. Which sensors are passive and active in two ways, the following details the passive sensors in different frequency characteristics of the product, as well as the main application.

First, the low-frequency (from 125KHz to 134KHz)

In fact, the low frequency RFID technology in a wide range of applications and promotion. The frequency is mainly through the inductively coupled manner, that is, the reader coil and sensor coils with transformer coupling. adoption of the reader role of alternating field in the sensor antenna induction voltage be rectifying that can be used for supply voltage magnetic field using. regions could very well be defined, but the intensity drop too fast.


1. work in low-frequency sensors of general operating frequency from 120KHz to 134KHz, TI 134.2KHz frequencies to. The band wavelength approximately 2500m.

2. Apart from the effect of metal materials, low frequency to pass through any material items without reducing its reading distance.

3. work in low frequency of readers in the world do not have any special license restrictions.

4. low frequency products have a different package. Good package is the price is too expensive, but there are more than 10 years of life.

5. Although the frequency of the magnetic field region declined quickly, but can be relative uniformity of reading and writing area.

6. with respect to the other band's RFID products, the band data transfer rate is slow.

7. sensors prices relative to other frequency bands.

Main application:

1. husbandry management system

2. car alarm and Keyless door system

3. marathon system application

4. automatic parking fees and vehicle management system

5. application of the automatic filling system

6. application of the hotel door lock system

7. access control and security management system

In line with international standards:

A) application of animal husbandry ISO11784RFID-coding structure

B) application of animal husbandry ISO11785RFID-technology theory

C) application of animal husbandry ISO14223-1RFID-air interface

D) application of animal husbandry ISO14223-2RFID-protocol definition

E) define the low-frequency ISO18000-2 physical layer, anti-collision and communication protocols

F) DIN30745 mainly European waste management application-defined criteria

Second, high-frequency (frequency for 13.56MHz)

In the frequency of the sensor no longer needs to be wound coil, can live through corrosion printing production of antennas. Inductor in General through the load modulation modes of work. It is through the sensors on the load resistance of connected and disconnected prompted the reader antenna's voltage changes, implement distance sensors on antenna voltage amplitude modulation. If people through data control load voltage is switched on and off, then these data will be transferred from the sensor to the reader.


1. the operating frequency is the frequency of 13.56MHz, about 22m wavelength.

2. in addition to the metal material, the frequency of wavelength can pass through most of the material, but often reduces the reading distance. The sensor requires some distance away from the metal.

3. the band in the world are recognized and no special restrictions.

4. the sensors are generally in the form of an electronic label.

5. Although the frequency of the magnetic field region declined quickly, but can be relative uniformity of reading and writing area.

6. the system with anti-collision feature, you can also read more tag.

7. you can put some data information is written to the tag.

8. data transmission rates faster than low frequency, price is not very expensive.

Main application:

1. application of bool management system

2. the management and application of gas cylinders

3. a garment production and logistics systems management and applications

4. three table prepayment system

5. Hotel door lock management and application

6. large conference staff channel system

7. fixed asset management system

8. medical logistics systems management and applications

9. smart shelf management

In line with international standards:

A) ISO/IEC14443 close coupling of IC card, maximum reading distance to 10cm.

B) ISO/IEC15693 sparse coupling IC card, maximum reading distance to 1m.

c)ISO/IEC18000-3 the standard defines the physical layer 13.56MHz system, anti-collision algorithm and communication protocols.

D) conform to the definition 13.56MHz 13.56MHzISMBandClass1 EPC interface definition.

Third, the very high frequency (frequency for 860MHz to 960MHz)

VHF system through the electric field to transfer the energy. Electric energy decline not quickly, but reading area is not very good. The band reading distance farther, passive to 10m. Mainly through capacitive coupling approach to implementation.


1. in the band, global definition is not very same-Europe and parts of Asia-defined frequency 868MHz, North America defined band to 902 to 905MHz, between the Japan proposed band to 950 to 956. The band of wavelengths around 30cm.

2. at present, the band power output current uniform definition (United States defined as 4W, Europe is defined as 500mW). May the European limit will increase to 2WEIRP.

3. VHF band radio controlled not by a lot of material, especially water, dust, mist, suspended particulate material. Relative to the high-frequency electronic label, the band of the electronic label does not require separate and metal.

4. RFID tag antennas are generally long and labels. Antenna are linear and circular polarized two designs to meet different application requirements.

5. the band have good reading distance, but is very difficult to read area defined.

6. has the very high data transfer rate, in a very short period of time to read large amounts of electronic labels.

Main application:

1. supply chain management and application

2. production line of automated management and application

3. air traffic management and application packages

4. a container management and application

5. railway package management and application

6. application of logistic management system

In line with international standards:

A) ISO/IEC18000-6 defines the physical layer and VHF communication protocol; air interface defines TypeA and TypeB two parts; support to read and write operations.

EPCglobal b) defines the structure of electronic goods coding and VHF air interfaces and communications protocols. For example: Class0, Class1, UHFGen2.

C) UbiquitousID Japan organization, define UID coding structure and traffic management protocols.

We have no doubt that in the future, VHF products will receive a large number of applications. Such as WalMart, Tesco, United States Department of Defense and Metro supermarkets are in their supply chain using RFID technology.

【 Weak current College 】 LED thermal solution analysis 】

Summary: LED circuit design in order to better address the thermal problem, LED and some high-power IC needs to aluminum base circuit.
LED aluminium baseboard design choices

LED circuit design in order to better address the thermal problem, LED and some high-power IC needs to aluminum base circuit.

Aluminum plate pcb by circuit layer (copper foil layer), thermal insulation and metal base. Circuit layer requires a lot of current-carrying capacity, which should use thicker copper foil, thickness 35 μ μ m m ~ 280; thermal insulation layer is the core technology of PCB aluminum plate, which is normally provided by special ceramic filled special polymer composition, thermal resistance is small, viscoelasticity fine, has the capacity of heat aging, able to withstand mechanical and thermal stress. IMS-H01, IMS-H02 and LED-0601, high-performance PCB aluminum plate heat insulating layer is precisely with this kind of technology that has very good thermal conductivity and high electrical insulation properties of strength; metal base is an aluminum plate of support structures that require a high thermal conductivity, typically aluminum or copper plate (which copper is able to provide better thermal conductivity), suitable for drilling, punching and cutting and other conventional machining. Technology requirements: gilt, gushes out the Tin, osp antioxidant, immersion gold, lead-free RoHS process, etc.

Base material: aluminium baseboard product features: small thin insulation, thermal resistance; no magnetic; heat; high mechanical strength product standard thickness: 0.8, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0mm copper foil thickness: 1.8um35um70um105um140um characteristics: high thermal resistance, electromagnetic shielding and high mechanical strength, excellent processing properties. Use: LED dedicated power hybrid IC (HIC).

Aluminum plate is the carry LED and thermal conduction, thermal devices or near the area, mainly concentrated heat conduction can choose high thermal conductivity of the material, such as the United States Bergquist plate; slow heat conduction or heat radiation General materials can be made. Price difference is large, Bergquist plates to produce finished products takes about 40 million square meters, General domestic materials to 1000 million square meters. LED General use voltage is not very high, select the thickness of the insulation voltage 1mil than 2000V.

Thermal reference design method:

Why thermal design?

High temperature on the impact of electronic products: insulation performance degradation; components damaged; materials for thermal aging; low melting point solder joint weld cracking and peeling.

Effect of temperature on components: in General, the lower the temperature resistance; high temperatures will reduce the service life of the capacitor; high temperature makes the transformer, choke coil insulation performance degradation, General transformer, choke coil allows the temperature is lower than 95C; temperature is too high it can cause changes in the structure of the solder alloy — IMC thickening, weld brittle, reduces mechanical strength; the rise in the junction temperature makes the transistor current amplification increases rapidly, resulting in an increase in the collecting electrode electric current, the junction temperature rise further, eventually leading to a component failure.

The purpose of thermal design

Control all electronic components within the product temperature, making it in the working environment conditions do not exceed the standards and norms of the maximum temperature. The maximum allowable temperature calculation should be based on the components of stress analysis, and product reliability requirements and are assigned to each of the components of the failure rate.

Thermal design is generally LED by fluid dynamics software simulation and do basic design.

Fluid flow resistance: due to the fluidviscosity and the influence of the solid border, make the fluid flow process subject to resistance, this resistance is called the flow resistance, can be divided into the frictional resistance and two local resistance.

Frictional resistance: in the border along the same region, fluid friction along the entire process of Sassafras resistance.

Local resistance: drastic changes in the boundaries of the region, such as section suddenly expanded or suddenly shrinks, elbow local location, is a fluid fluid state undergoing drastic changes and flow resistance.

Usually LED is the use of the natural thermal radiators, heat sink design for a three-step 1: design in accordance with the relevant constraints outline at. 2: according to the heatsink design standards on the radiator tooth thickness, tooth shape, tooth pitch, substrate thickness for optimization. 3: conduct check calculation.

Heat sink design method

Natural cooling heatsink design method

Considering the natural cooling temperature boundary layer thick, if tooth spacing is too small for two teeth of thermal boundary layer is easy to cross the influence of the tooth surface, convection, so in General, the recommended natural cooling heat sink teeth spacing greater than 12mm, if the heat sink teeth high below 10mm, tooth pitch ≥ 1.2 tooth height to determine heat sink teeth spacing.

Natural cooling radiator surface heat capacity is low, increase in heat-tooth surface corrugation does not have the effect of natural convection is too large, it is recommended that the heat surface of teeth without ripple teeth.

Natural convection radiator surface blackening treatment generally used to increase the cooling surface of the radiation factor, strengthening radiation heat.

Due to natural convection of heat balance reached for a longer time, so the natural convection radiator of substrate and tooth thickness should be sufficient to combat the impact of instantaneousheat load, recommends ¡ôduring above.

【 Weak current College 】 electrolytic capacitor of electrical parameters 】

Here the main means of electrolytic capacitors, Aluminum Electrolytic Capacitor, its basic electrical parameter includes the following five points:
1, capacitance value

Electrolytic Capacitor tolerance values, depending on the AC voltage work the impedance. Therefore capacity value, AC capacitor value, along with the working frequency, voltage, as well as the measurement method. The provisions in standard JISC5102: aluminum electrolytic capacitor capacitance measurement condition is in frequency as 120Hz, maximum AC voltage to voltage 0.5Vrms, DCbias 1.5 ~ 2.0V conditions. Can assert, aluminum electrolytic capacitor capacity increase of the frequency decreases.

2. loss angle tangent of δ T a n

The equivalent circuit in the capacitor, in tandem with the equivalent resistance ESR capacitance 1/C ratio called ω T a n δ, ESR is here at 120Hz calculated values obtained. Obviously, T a n δ with measuring frequency increases, the larger, with the measurement temperature decreases.

3, impedance Z

In the specific frequencies, impeding the AC current through a resistance which is the so-called impedance (Z). It and capacitance equivalent circuit of capacitance, inductance values are closely related, and are also related with ESR.


Type, XC = 1/ω C = 1/2 to π f C


Capacitor capacitance (XC) in the low frequency range as the frequency increases gradually to reduce the frequency, continue to increase reach medium frequency range reactance (XL) to ESR values. When the frequency reaches high frequency range inductive reactance (XL) becomes dominant, so the impedance is as the frequency increases.

4, leakage current

Capacitor's media on DC has great impediment. However, because the aluminum oxide film media soaked electrolyte, voltage, and fix again formation of oxide films will have a very small called leakage current of electricity. Generally, residual flows with temperature and voltage but increased.

5, ripple current and ripple voltage

In some of the information in both called "ripple currents" and the "ripple voltage" is actually ripplecurrent, ripplevoltage. Meaning is the capacitor can withstand ripple current/voltage values. They and the close relationship between ESR, you can use the following equation:


Type, Vrms said ripple voltage

Irms said ripple current

R represents a capacitor ESR

Top visible, when the ripple current increases, even in ESR remain unchanged, the ripple voltage will increase exponentially. In other words, when a ripple voltage increases, ripple current is increased, this is also called capacitor with lower ESR values. Fold to join the ripple current, because of the internal equivalent capacitance series resistance (ESR) cause the heat, thus affecting the life of the capacitor. General, ripple current proportional to the frequency, low frequency is also relatively low ripple current.

【 Weak current College 】 LED bar Panel Assembly method 】

1.LED article screen Overview:

LED screen, as new media, graphic, motion of light-emitting more easily attract people's attention, informative, at any time update, with a very good-; advertising and signage. LED screen easier than neon light, easy to install and use, effect change more, you can update the content at any time, is very good-; of indoor and outdoor, Visual media. LED screen is high-tech electronic products, the price is quite high, previously concentrated in Government and units. Technology-; progress, price decreasing, Assembly and maintenance easier. Mini led strip screen, because the price is cheap, easy to install and use, long been big-; accept, gradually went into the shop, the more the size of the applications, to gradually start universal popularity.

2. Article screen application:

2.1. advertising application---new media, new effects, new business

LED bar screen as new media, and also the type of decoration materials that can be embedded into many interior decoration, the decoration is more full of dynamic, continuously updated titles, you can notice board as new, promotional offers and promotional information, etc. Greatly improves the interior decoration of grades, and enjoys a good visual effects. Because the LED bar screen of the installation and use of certain technical content, constraints on the development of the advertising industry. Master LED technology, you can improve the interior decoration of technical content, expand their business. -;-;

2.2. system integration--2-dev

LED bar screen, a simple control, embedded into all kinds of the equipment for the mass. Fonts, full of dynamic, informative, suitable for long-distance watch broadcast to the public in a timely manner, to attract public attention. Widely applies to the queuing system, announce system, drinking fountains, etc. LED bar panel control card, features a simple, stable, and can be easily embedded into the system, as the Developer saves development LED display of cumbersome work, to focus more on the system's functionality and innovation. LED bar panel control card development kit, provides detailed examples of development, system integration and 2 development provides very good environment.

3. Assembly of significance

LED industry chain is very perfect, all parts can be easily bought on the Internet, LED by the technical parameters, the increasingly consolidated, industry standard basic formation, all spare parts are modular. For self Assembly LED screen. LED bar display, because the material cost is low, the retail price, when the batch to the LED screen suppliers, cost and price is not well controlled. End users are not familiar with the LED screen, need vendors provide installation and maintenance services, so self Assembly LED screen, local sales, you can get the maximum profits.

For example: assembled 1 128x16 point single red LED screen of indoor, by connecting PC serial update the contents of the screen;

3.1. screen composition

Let us look at LED article screen, unit Board, power supply, control card, line

3.1.1. the unit panels

Cell plate is led display, one of the core parts, modules or bad, directly affects the display effect. Cell plate by LED module, driver IC and PCB Board composition. LED module, in fact, is a much more LED light-emitting points with resin or plastic encapsulated dot matrix. Driver IC mainly 74HC59574HC245/24474HC1384953. Indoor article screen common cell plate specifications: parameters: D = 3.75; dots 4.75mm64 point wide x16 points high, 1/16 sweeps indoor brightness. Single-red/red-green two-color parameters explained: diameter: refers to the light-emitting points diameter D = distance 4.75mm 3.75mm luminous point--– depending on the viewer's distance, indoor unit panels generally select 4.75 size: 64x16---the most commonly used unit panels, the most easy to buy, the price is the cheapest.; 1/16 sweep: cell Board of control. Indoor brightness: refers to the brightness of the LED luminous point, indoor brightness for fluorescent lighting during the day and need to rely on the environment. Color: red, most popular, price is the cheapest. Two-color generally refers to the red and green, the price is high. If you want to be a point in screen 128x16, only require 2 units plate threaded together.

3.1.2. power supply

General use of a switching power supply, 220V input, 5V DC output. It should be noted that, because of the LED display screen is a precision electronic devices, so you want to use the switching power supply, you cannot use the transformer. For one single red indoor unit panels, 64x16 dawn, current of 2A. Reasoning out, full-color screen 128x16 light when current 8A. Should select 5V10A of switching power supply.

3.1.3. Control card

We recommend the use of low-cost bar screen control card, you can control the 1/16 the Sweeper bicolor 256x16 points, you can assemble the screen on the cost advantages of the LED screen. The control card belongs to asynchronous card, that is, the card can be powered off to save information, do not need to connect a PC can display the information stored in it. Procurement Unit panels, please ask the clear parameter, 100% compatible cell Board are:

08 interface 4.75mm point distance 64 points wide x16 points high, 1/16 sweeps indoor brightness. Single-red/red-green two-color;

08 interface 7.62mm point distance 64 points wide x16 points high, 1/16 sweeps indoor brightness. Single-red/red-green two-color

08 interface 7.62mm point distance 64 points wide x16 points high, 1/16 the brightness sweep semi-outdoor. Single-red/red-green two-color

3.1.4. on 16PIN08 interface-; because of the cell boards and control card manufacturers, so the unit panels interface style, in the Assembly LED screen, you must first determine the add-inMouth consistency, is easy to assemble. Here only themost commonly used LED interface: LED industry number: 16PIN08 interface: he explained: the order of the interfaces to ABCD rows selected signal, STB (LT) for latch signal CLK (CK) is a clock signal, R2, R1, G1, G2 to display data that is displayed enabling EN, n is the ground (GND). Confirm unit panels and control card interfaces, you can connect directly. If you do not agree, you need to make a conversion (conversion at line order

3.1.5. wiring

Divided into data lines, transmission lines and power cables. Data cable for connecting the control card and LED unit panels of wire, transmission line to connect the control card and computer. Power cable, is used to connect the power supply and control cards, power supplies and LED modules. Connect the power cable from the unit Board of copper conductor diameter is not less than 1mm (mm)

3.2. accessories production

3.2.1. the cable (cable) production

Wire and computer cables inside the chassis is similar, except that the width of the line is a little different. You can buy at computer city to related materials. Making row line, you need a tool that is special pliers (picture), you can greatly improve work efficiency and yield. Production of wire materials: wire, thread, wire Cap. Here it is necessary to pay attention to it, if you make 16PIN (16 line) of the wire, you will need to purchase the line and the corresponding 16PIN size emission caps and hats. Production steps, the head and use scissors to cut flat, and then on the front row head, (Note line and head of the balance), and then into the central pressure of pliers, hard pressed and then put the lines round, the installation of a drain line cap. Drain CAP is important, you can effectively protect the wire, wire more sturdy, not provincial.

3.2.2. the power cord manufacture

Power supply is divided into 220V power and 5V power supply line. 220V power cable for connection to mains switching power supply, preferably with a 3-pin plug, you can buy at the hardware store. Here focuses on 5V DC power cord, 5V current is relatively large, it is best to use copper conductor diameter more than red black 1mm on line (be sure to red and black). The best conditions, at the ends of the line fitted with metal pieces-;-;

3.2.3.RS232 line production

RS232 cable for the connection of computer and control cards, data update screen. Here you need the DB9 's head and a network cable (you can buy at computer City). Carefully observed DB9 head, digital, 5 3 connecting Palm, will connect brown white. Will Web Clip, installed in the DB9. (This is very important, be sure to clamp to pull a few myself to see if a pull-off). Then use multimeter measuring it, whether on-. Here it should be noted that the head of the DB9 male and female Division head. Computer mother, later belonged to, so you want to buy a plug to correspond. If you do not understand please take a closer look at your PC. Now no serial port of a notebook, please purchase a USB to RS232 serial line

3.3. wiring Guide

First time installation, please follow the steps to operation, reducing the error occurred.

Step 1: check the power supply voltage, positive and negative connection out DC switching power supply, connect the power cable 220V switching power supply, (confirm connection correctly, the connection to the AC or NL terminals) and then plugged in. Will find power supply has a bright light, and then use the multimeter, DC shift measurements V + and V-voltage between, ensure that the voltage between the 4.8V-5.1V, side have the knobs to adjust the voltage of a Phillips screwdriver. In order to reduce screen fever extend life, less demanding in the brightness of the occasion, you can put between the voltage regulator to 4.5V-4.8. Confirm that the voltage is no problem, disconnect the power and continue to build other parts.

Step 2: turn off the power. The V + connect red line, V-connection to connect the black wire, riser and LED unit panels, the black line received control card and power supply GND. Red line connection control card + 5V and cell Board of VCC. Each cell Board 1 wire. When you are finished, check that the connections are correct.

Step 3: connecting the control and the unit Board, use the cable, the connection. Note the direction cannot be reversed. Please note that cell Board 2 x 16PIN connector, 1 is input, 1 output, near 74HC245/244 is input, the control card is connected to the input. Output connection to next module input.

Step 4: connect the RS232 cable that will connect the data cable to a PC serial port DB9, the other side of the connection control card of 5 pin DB9 (Brown) to connect to the control card of GND, 3 feet of the DB9 (Brown and white) to connect to the control card of RS232-RX. If your PC has no serial port, you can buy a computer city USB to RS232 serial port for converting line.

Step 5: check again whether the correct line, black lines connect-V and GND. The Red wire is connected to VCC + v, and + 5V.

Step 6: connect 220V, normally, the power light on the control card, the screen is displayed. If you are not working properly, please check the wiring. Or view the error and repair.
If the screen has two unit panels display the same content, please use the software to set the screen size is 8 characters.

Weak current College】 【ups professional vocabulary analysis】.

<br> Ups: ups (uninterruptiblepowersupply) literal translation for uninterruptible power supply systems. As computer systems, in particular the protection devices on the network, which mainly serve two purposes: one is to provide backup power for computer system, in order to prevent .sudden power off power supply to damage the computer system; the second is the Elimination of power supply "pollution" (including the surge, volatility, pulse, noise, etc.), so that the computer's electronic components against destructive damage. <br> .Online UPS: online (online) UPS features can power up to "purify" role, and overload protection function and strong anti-interference ability, the quality of its power output than the backup type, also known as offline (offline) UPS is much .higher. Holdover time is longer, it is one of its advantages. In accordance with its history and can be broken down into serial UPS and line interactive ups two categories. <br> Serial-ups-ups: concatenation is currently the most commonly used .a ups, it and off line ups maximum difference between AC power supply, it is also normal. Because good stability and security, and therefore better suited to a variety of large-scale applications, the drawback is the circuit design of complex structures, maintenance .is difficult, a higher price. <br> Line interactive ups: line interactive ups is in serial-ups developed on the basis of a new technology. It in precision regulator, running stability, intelligence, security, and so does have characterised. Especially .on more than 3000 Watt, bulk in ups, taking into account how users of large computer systems and network servers, so the voltage on the higher requirements, and security protection is necessary should be. As a new product it is steadily enters the UPS market ., is affected by the cost of production, within a short period of time, it is still difficult to replace the serial type. <br> Ups output wave form: according to their works, ups has squarewave, stepwave, sinewave three output waveforms. .It is now widely used is the sinewave. <br> Ups load power: the UPS load power refers to ups do power supply that can support the sum of the power of the device. Only the sum of the device power is less than the ups .load power ups to ensure long-term and stable work. <br> Ups power factor: UPS power factor including input power factor and output power factor in two parts. The former is the ups do load from power gets effective power; the latter is .the ups do power supply power to the other load output power. Not provide the power, the greater the UPS output power factor. <br> Ups: ups efficiency of absorption from external power and to load the output power is the ratio between is ups .efficiency. Efficiency can only show that the consumption of power ups in itself, and does not reflect the level of the power factor. <br> Ups battery pack: ups delay length depends to a large extent on the capacity of the battery pack. Especially .large capacity battery pack, it almost to account for the overall price of ups 1 / 4 or so. The battery itself, its failure causes the ups is not working in high percentage, while maintaining the degree of difficulty, the loss should not be underestimated .. <br> Ethernet: General LAN often use this standard to be connected to the computer. <br> Three-phase: standard power system is a three-phase power supply, for each phase are sine wave and the difference of 120 degrees phase .and single phase of only one of three-phase phase only. <br> Synchronization: ups output produced by the sine wave power and input AC power is a sine wave, and they are required to maintain the frequency and phase. This is synchronized. .<br> Synchronous converters (SYCHRONOUS): is between two power supplies and loads a converter between. <br> Not synchronous converters (ASYCHRONOUS): cannot be a number between two power supplies and loads a converter between. <br> Continuous electrical power .systems ups: (UninterruptiblePowerSystem (orSupply)). Its function is to protect your valuable equipment, extension of the emergency escape apparatus of power, avoid power outage or electrical instability phenomena reducing device of life, to prevent power high surge harm and damage to equipment ., etc. <br> Water lines: single-phase power system, the water line of the function for the conduction current feedback, and the socket-to-ground allocation in the same area. But in the Taiwan region, only the water line .and the line of fire. <br> Power factor: this value is typically a value between 0 and 1, and its value must not be greater than 1, it is W (full power) and VA (virtual power) values than the number .and proportion of high and low, the proportion is higher then the electrical efficiency of the better, rather than the lower the number, it means that the appliance itself consumes energy increases, the more power. <br> Distortion: distortion into wave distortion, .voltage distortion, current distortion ... And so, no matter what kind of distortion, both as a percentage to calculate the size of its distortion and harmonic, voltage, current, and power factor. (Refer to the HARMONIC chapters) <br> .City: that is our common names of alternating current (AC), AC components include: voltage, current, frequency, the frequency of three can be divided into 50HZ (in Hertz) and 60HZ (in Hertz), voltage distribution, 100V ~ 240V .. In Taiwan using 60HZ/110V AC. Normal AC waveform for a sine wave, but also useful step wave composition similar sine wave, the wave is not applicable to the motor or inductive load equipment. <br> Handshake: in computer communications, the .two devices before beginning to communication, you must understand each other's status, as well as the method you use, if both of the situation, the computer will inform the consumer related information. <br> Common mode: refers to the circulation path interference noise .in a wayThe power that comes from the line of fire (Hot) or water (Neutral) and through the ground noise, as returned by the EMI. <br> Online-power system: ie to ONLINEups, its main circuit structure: surge absorption .filter circuit converts direct current circuit, alternating current (AC / DC) converts AC circuits, direct current (DC / AC), microprocessor control circuit, bypass, five. The action mode: normal in AC, AC surge absorption filter circuit via → AC .conversion converts direct current circuit ¡ .ú DC and AC circuits → convert AC output supply load, and charge the battery at the same time; once the microprocessor control circuit detection to the mains, immediately by the battery discharge → AC DC conversion circuit → and convert AC output supply load use. .If the microprocessor control circuit detect ups fault, ups will take the relay (Relay) skip to bypass (Bypass), from the mains power supply load and beep to inform users. <br> Valid values: Root-Mean-Square (RMS) .(or root-mean-square value). In alternating current or voltage sine wave, the valid values are 0.707, this data is based on a sine wave voltage and current in 1 cycle the conversion of energy peak. Bit: the computer data, .it is the smallest, only 0 and 1. Byte: a byte, a total of 8 Bits (bit). Serial port: used to transmit the signal connectors. (Refer to RS-232, Transfer (Asynchronous)) <br> Silicon .base is increasing to Silicon diode: (SILICON) is the main material of the design of diode, Diode Silicon base increase and General diodes different places is that when the voltage exceeds the rated voltage of the design, the diode will produce additional barriers effects ( .AvalancheEffect) and conduction, silicon base increase diode common do Zener diode. <br> Ann hours (AH): reflects the size of the battery capacity, its one of the indicators defined by the current discharge time. The same as the voltage of the .battery, the number of large capacity; the same number of batteries when Ontario, voltage high capacity. Usually when a voltage and indicates the number of common, such as the battery capacity 12V/7AH, 12V24AH, 12V/100AH 12V 65AH, /. .<br> Arrester for Lightning wave absorption device, works by lightning produces instant high voltage into the circuit, causing the lightning current arrester breakover absorption, circuit voltage clamp in the safe range. Surge arrester fittings can be used as a variety of components, such .as pressure sensitive resistor, discharge pipe, etc. Note: Thunder voltage is between the atmosphere and the Earth, so the high-voltage spark arrester to have a good grounding to work. <br> FUSE: a fuse-overheat of small devices, .overloading or load short-circuit current Assembly caused by blowing a fuse to protect electronic devices is not supported by overcurrent damage, also avoids electronic equipment because of internal troubles caused serious harm. Therefore, each fuse rated specifications on both, when current exceeds the rated .specifications fuse will fuse. Note: If you are not using the original factory with the specifications of the fuse might result in machine failure, or fire damage caused by the line, its own security. It is best to use the original factory with the specifications .of the fuse to protect the device can also be protected to ensure the security of the person. <br> Transformers: the use of electromagnetic induction principle, from the core and coil form, can be divided into one side of the coil and the secondary .winding of two parts, one side of the input voltage, secondary side have induced voltage output, for power delivery. Secondary side can provide a wide range of voltage output, step-up, step-down, transformer circuits can meet a variety of different .voltage power demand. <br> Voltage accuracy: means the output voltage of the amount of relative change, as a percentage, as small as possible. When the input voltage or load changes, the UPS output voltage will be raised or lowered, change the .smaller description higher voltage stabilizing precision. <br> Reactive power: unit is the VA, it is not absorbed by the load, so called reactive power, which make up the apparent power of the other part. Reduce reactive power increase network utilization. < .br> Line voltage: current after line will result because the line impedance, forming line pressure loss. Line voltage drop and proportional to the length of the lines, and lines of cross-sectional area inversely. <br> Backup power system: the original .main means diesel generators, gasoline generator, and so on, these ups does not appear in the early days, when the mains power equipment as a standby. But there, since ups ups has the added benefit of allowing you to respond quickly to dynamic, .adjustable output more stable, eliminating absorption power external adverse impact protection of electrical equipment. Thus, contemporary standby power ups in occupies more gradually. <br> MCU: using computer hardware and software technology for micro-control unit. <br> Charger for charging .the battery, to fill a charge energy device. Note: 1. the battery capacity, the greater the larger the charge current, otherwise the long charging time. 2. Select a suitable charging model makes protection battery and charging efficiency. 3. long delay .UPS battery charger cannot use standard machine charger replacement. 4. the charger's damage is likely to lead to a failure of the entire set of batteries. <br> Conducted interference (EMI): spread through the power line EMI noise. <br> RS485 .interface: enables multiple-station Internet and remote transmission of computer and other equipment for differential mode serial asynchronous transfer data signal standard interfaces. RS485 generally two data lines, the transmission distance of up to 1000 meters above the sea level. <br> Unit: .usually refers to diesel or gasoline generator. <br> Noise: used to describe the human sound quantitative sensory physical quantities, general use dB noise, ups generally 40-80dB. Active power: W is the unit is to load the real transformation of energy .absorption, it formed a part of the apparent power. <br> Differential mode EMI interference / (DifferentialMode): means interference noise flow paths. Those coming from the power supply line (HOT) and through the zero line (NEUTRAL) noise called differential .mode noise. Those coming from the power supply line (HOT) or zero line (NEUTRAL) and through the noise of the ground wire, called common mode noise. The General noise is not a common mode of constituencies path is the differential mode paths for .different paths of noise using different processing, by filtering, shield, and other means to eliminate. <br> IGBT: there are three levels, usually G, E, C, G, E-plus control signal can vary between E, C and .due to conduction.-For voltage IGBT, MOSFET driver with high-speed switching characteristics and low on-resistance of transistors. <br> Varistor: is the power input of a protective device, can absorb the input voltage, electrical devices plugged into the .wrong power or power surge is too large, all cause it damage. Device varistor role: to protect the internal electronic components and electrical appliances <br> MOSFET: there are three feet, usually G, D, S, G, S between control signal .can vary between D and S and due to conduction. MOSFET for voltage drive parts. <br> Zener diode: reverse current is large enough, the device's reverse voltage stable in nominal values are the same as the properties and diodes. <br> Reboot .: means an uninterruptible power supply is restored in the city. It can be manually restarted or predetermined by the software, the ups protection after reboot to reset. <br> Conducted interference (EMI): spread through the power line EMI noise. <br .> Charger for charging the battery, to fill a charge energy device. <br> Note: <br> 1. battery capacity, the greater the larger the charge current, otherwise the long charging time. <br> 2. Select a suitable charging .model makes protection battery and charging efficiency. <br> 3. long delay UPS battery charger cannot use standard machine charger replacement. <br> 4. the charger's damage is likely to lead to a failure of the entire set of batteries. <br> .Battery / battery: the battery ups are usually sealed maintenance-free lead-acid batteries. This type of battery of physical and chemical properties make it in the charge and discharge process almost no moisture loss, does not need to add water, place the sealed .structure to arbitrary, no corrosive gases, without maintenance. <br> Standard battery voltage is 2V, 4V, 6V, 12V, ups the most commonly used is 12V. A battery voltage is not enough, it use only with multiple-line form the .battery pack. Note: maintenance free sealed lead-acid battery life in fact, and how to use and is closely linked with the environment, you should note the following: <br> 1. does long-term storage is not used, this battery .will lose its activity, leading to an eventual failure. <br> 2. battery suitable environment temperature is 20 degrees, higher than 40 ° life will shorten, less than zero is a valid capacity decrease. <br> 3. depth of discharge in .the future you want to use in a timely manner, often deep discharge is not conducive to battery life. <br> 4. discharge (discharge below the battery rated lower voltage) damage to the battery. <br> 5. charger reliability and proper .charging capability is essential to life. Power adjustment rate: input change output voltage accuracy. Communication protocol: Internet device for data exchange between the common rules. <br> SNMP: Simple Network Management Protocol's initials, mainly used for monitoring, troubleshooting and control TCP ./ IP network, providing user data programming of simple network management protocol. <br> Input frequency range: standard frequency is in China power grid, power ups allows 50Hz frequencies have a certain range, in this context, ups power supply frequency synchronous tracking, .beyond the native frequency output. <br> Current peak factor (CF): the current peak factor refers to the current waveform peak and RMS. Because the computer load accepts its sine wave voltage is not necessarily the energy absorbed by the sine law, results .in a higher peak current (between 2.4-2.6 times current), therefore, ups design should provide CF value is greater than 3 current to meet computer load applications. <br> Battery in series / parallel connection: more performance capacity the same battery according .to certain polarity serial connection overlay is the concatenation, the formation of the battery pack; multiple voltage is the same battery or battery in the end, by the same polarity connections to form parallel output is parallel. <br> Battery management system, used for .protection of ups batteries and extend its life, the best charging effects. Battery management system includes software and hardware, including battery charging characteristics judgment, mode of automatic selection, automatic alarm and special battery charging and many other technologies. <br> <br> .<br> <br>.

Weak current College】 【LCD TV bad points and detecting methods】.

Today's big-screen TV at the hottest products, especially in the new House of friends also can't wait to buy one ideal liquid crystal. But when the LCD TV sent home after you have noted the existence of a pixel? what is a bad point, its use of the LCD TV has much influence, how to detect bad points and avoid the bad points of the LCD TV?
LCD TV with pixel and LCD monitors, mobile phones and other products using the LCD Panel, because the control a pixel brightness change the effectiveness of the transistor. We know that LCD Panel works by semiconductor transistor control applied to voltage, liquid crystal lens to let the liquid crystal molecules are arranged by state changes, the implementation of each pixel shading. When control liquid crystal molecules rotating transistor failure, bad points. Transistor failure has two consequences, one is always powered up, one is always closed, so LCD pixel there bright and dark spots. As long as the post, bad point is always displays a color. Relative, bright images of dark far dark screen highlights to conspicuous, so highlight is our particular attention. It is also for comparison and annoying bright spots, but also manufacturers through technical means will highlight off, launched guarantee zero bright slogan, but this does not mean that there is no bad points, but it makes a bad point is not so easy to find.
Testing the LCD Panel of bad point is a test of patience and eyesight, because each pixel LCD Panel divided into red, green, blue three subpixel, so we just need to let the LCD TV show black, white, red, green, blue three colors screen, you can let bad point no undetected.
Method 1: on the TV set at home, use a computer and LCD TV is connected to is display a variety of solid colors screen, this is the best way and the steps of selecting the LCD monitor. Of course, the computer graphics and the TV is connected first of all to consider both have a common interface, such as the most universal VGA interface, if the TV has a VGA connector, simply prepared a VGA cable, turn on the TV and choose PC (VGA) input signal source, follow the instructions that are described in the television supports resolution settings, if your TV only support up to 1024 x 768 for 4: 3 signals, the screen will only appear in the middle area, we can adjust the screen ratio to expand to full screen. After like TFTtest, checkscreen, DisplayMate, solid color images in the software to display the desired picture. You can also select computer desktop properties where the corresponding color of the desktop to detect, and purchase the LCD monitor when detection methods.
Method 2: many computers also support read CF/SD memory cards, USB flash drive to appear in the picture, so we can also use these attachments to show these solid color screen. First brush, making these tools phptoshop JPG format of solid color picture, and then, in the resolution to 1280x720 card or Flash drive and use the TV as much as possible full-screen display these pictures.
Method 3: If you happen to have such a test disc HiVicast or DVD machine to act as a signal source, select the required test screen sections. If you do not have such a test drive, you can also select other DVD discs near we want solid color images of fragment, for example at the beginning of the copyright warning screens, menus, subtitles, and so on, at the end of the moratorium on display to detect.
If the above condition is met, we had to connect the cable TV, a television program is relatively suitable for screen, through TV static like function to detect.
Not all LCD TV has a bad point, all the manufacturers are the number of bad point in how much scope remains normal, there are three or less, while others are 5 or 8 or less, and the different levels and Panel and respective manufacturers for quality control of demanding level. Of course, as consumers must not willing to spend big money to the LCD TV and bad points, but the current LCD TV sales are in the marketplace money order, then by the manufacturers charge, therefore prior to consultations with vendors clearly how much a bad point you can return to the TV to check as soon as possible after, so that time too long, been for depreciation or refuse a purchase.
A LCD Panel has no bad point, manufacturers are know, there are no bad point is the decision of the LCD Panel grade and an important factor in the price, so when we select LCD TV, you should try to avoid those super low price of the product, and select high-profile brand. Of course, even if there are a couple of bad points, but also not depressed because the LCD TV viewing distances under normal viewing distance, and not easy to find, especially in the side position, almost difficult to detect, more impact only derived from the psychological level.

Monday, February 14, 2011

【 Weak current College 】 Hitachi high speed refrigerated centrifuge 】

Trouble phenomenon: Hitachi 20PR-52D high-speed refrigerated centrifuge refrigerator with red LED light

Fault analysis and repair of aircraft used: freon refrigerant, R505 as compressors for closed 1100W, and general stand-alone refrigeration systems, different places are: the compressor pipeline another after another pipeline, central control by a solenoid valve, pipe plug access evaporator import pipeline. Aim when defrosting system, you can automatically open solenoid valve automatic defrost quickly, and can automatically adjust the temperature of the cavity stable centrifugal.
When it finds a refrigerator light, freezer stopped. First, check whether the bottom of the compressor temperature above 70 ° c, while at the same time check the supply voltage is 220 ¡à 20V. If none of the above normal, then view the compressor side at 220V. If you check the overload protection. When you view the overload protection role, the compressor failure, check the compressor end line and shell resistance value, close to zero, the coil of compressor or short-circuit to ground the end line. This fault has obvious phenomenon as an out-of-the-stop the compressor.
First of all to replace a compressor, the first open air pipe, the freon fact, with the compressor pipeline welding and gas welding opened, remove the compressor, install a new compressor, access line, open the leak detection, leak-free via check, vacuum, and fluoride, commissioning normal seal inflatable tubes.

【 Weak current College 】 cold storage capacity is determined by the method 】

A, cold storage tonnage: active cold tonnage = refrigerated between internal × volume utilization coefficient × food unit weight

Activities in the cold store refrigeration rooms of internal = library, length × width × high (cubic)

Cold storage capacity utilization coefficient:
500 ~ 1000 cubic meters = 0.40
1001-2000 cubic = 0.50
2001 ~ 10000 cubic = 0.55
10001 ~ 15000 cubic = 0.60

Second, the activities of the cold storage of food unit weight:
Frozen meat = 0.40 tonnes/cubic
Frozen fish = 0.47 tonnes/cubic
Fresh fruits and vegetables = 0.23 tonnes/cubic
Mechanism of ice = 0.75 tonnes/cubic
Frozen sheep cavity = 0.25 tonnes/cubic
Boneless meat by-products or segmentation = 0.60 tonnes/cubic
Tank frozen poultry = 0.55 tonnes/cubic III activities cold storage warehousing capacity calculation method: 1 in the warehouse, the maximum storage capacity of the formula:
Effective internal volume (m3) = total internal volume (m3) X0.9
Maximum storage capacity (ton) = total internal volume (m3)/ 2.5m3

2 activities of cold store actual maximum storage capacity
Effective internal volume (m3) = total internal volume (m3) X0.9
Maximum storage capacity (ton) = total internal volume (m3) X (0.4-0.6)/2.5m3
0.4-0.6 is cold
storage size and stock. (This form is for reference only)

Ordinal 1 2 3 4 5 6 7
Food category meat frozen fish fresh eggs, fresh vegetables and fresh fruit ice ice egg mechanism
Severe 400 kg/m3 470 260 230 230 600 750

3 the actual amount of storage used
In the absence of a special occasion, you specify the actual amount of storage used in accordance with the maximum amount of storage (tons) of 15%
Or 30% (100m3 generally less than by 30%).

Weak current College】 【switching power supply design knowledge describes】.

<br> <br> 1 introduction of electronic products, especially military power supply design is a systematic project, not only to consider the power supply design parameters, but also the electromagnetic compatibility of electrical design, design, thermal design, security, design, .and three prevention design. Because any aspect of even the most minor negligence, this can cause the collapse of the entire power, so we should be fully aware of the power of the importance of product reliability design. <br> 2 switching power supply design .electrical reliability power supply mode select 2.1 centralized power supply system all output deviation as well as the transmission distance of different pressure difference resulting from reduced supply quality and application of a single power supply, power supply failure may cause system crashes. Distributed power supply system for .power supply unit closer to the load and improve the dynamic response characteristics, power quality, transmission loss is small, efficient, energy saving, high reliability, easy form N + 1 redundant power supply system, extended power is also relatively easy. So the use .of distributed power supply system can meet the requirements of high reliability of the device. 2.2 circuit topology selection switch power generally use the converter, Flyback, double transistor Flyback, dual converter, double forward-style, push-pull, half bridge, full bridge .eight topology. Converter, Flyback, double <br> Converter, push-pull switching pipe pressure at two times the input voltage above, if the 60% Derating, you make the switch easy selection of pipe. In push-pull and full-bridge .topology might appear one-way biasing saturated, so switching valve damage, and half-bridge circuit since have auto-resistance unbalance capacity, so this problem does not occur. Double transistor Flyback and half-bridge circuit switching valve's confined only to the power of .maximum input voltage, even by 60 per cent for use, select switch tube also easier. In high-reliability engineering general use both types of circuit topologies. 2.3 control strategy choice in small and medium-sized power supply, current-mode PWM control is .a large number of methods used, it is a voltage control type has the following advantages:-by-cycle current limit, voltage-mode control faster, from overcurrent, switching valve damage, significantly reduce overload and short circuit protection; excellent voltage regulation; .fast-transient-response; loop stability, easy compensation; ripple voltage control type. Production practice indicates that the current control-50W switching power supply's output ripple around the 25mV, over voltage control type. Hard switching technology due to the switching loss limit, .the switching frequency is generally 350kHz following, soft-switching technology is applied, the resonant principle at zero voltage switching components or zero current state on / off, switching loss is zero, thus increasing the switching frequency to megahertz level, the application of soft- .switch technology converter integrated PWM converter and resonant converter both advantages, close to the ideal characteristics such as low switching losses, constant frequency control, appropriate storage component size, wide control range and load range, but this technology mainly used for high-power power, .small and medium-sized power supply is still dominated by PWM technology. 2.4 components selection because components directly determine the reliability of the power supply, the components of the selection is very important. Components of the failure is mainly concentrated in the following four aspects: .(1) the quality of manufacturing quality problems caused by failure of work stress. Quality is not qualified to be through strict examination, when the application should use fixed-point production factory and mature product, does not allow the use of certified products. ( .2) components reliability issues components reliability issues that the basic problem of failure rate, this is a random nature of the failure, and the quality difference is that the components of the failure rate depends on work stress levels. To a certain level of stress, .the components of the failure rate is significantly reduced. Culling does not meet the requirements of the use of components, including electrical parameters not qualified, the sealing property is not qualified, the appearance is not eligible, poor stability, early failure, etc., .should be screening test, this is a non-destructive testing. By filtering allows components to reduce failure rate 1 ~ 2 orders of magnitude, of course, screening cost (time and cost) are large, but comprehensive maintenance, logistics support, the entire .frame with the discussion, or cost-effective development cycle, will not be extended. Power device main components of the screening test General requirements: ① resistance at room temperature according to the technical conditions for 100% test, excluding the non-conforming product. .② normal capacitor at room temperature according to the technical conditions for 100% test, excluding the non-conforming product. ③ connectors according to technical conditions of the various parameters of the sampling inspection. ④ semiconductor device filter in the following programs: eye checked → .epicenters → high temperature storage → high-temperature impact → power aging → high-temperature test → low temperature test → at room temperature after the end of the test screening should be calculated excluding the rate QQ = (n / N) × 100% type .: N - the total number of samples; n - the number of samples taken out; if Q over standard prescribed limit value, the number of components not hands-on, and all relevant provisions. In line with standard requirements, you will filter the .qualified components make paint dot callout, and then into the private storeroom for machine use. (3) design issues first is properly selected appropriate components: ① selection Silicon semiconductor devices as possible, less or no germanium semiconductor devices. ② the use of integrated circuit .and reduce the number of discrete devices. ③ switching valve selection MOSFET simplifies driver circuit, reduce losses. ④ output rectifiers as far as possible with soft recovery diode characteristics. ⑤ should choose metal packaging, ceramic packaging, glass encapsulation of devices. Prohibition of the .use of plastic packaging. ⑥ integrated circuit must be a class of goods or is compatible with standard B-1 MIL-S-19500 MIL-M-38510, more quality levels of the military. ⑦ design-time use relay, warranted should use .sealed relay contact good. ⑧ principle, selection of potentiometer, must be kept on the casting processing should be carried out. ⑨ absorption capacitors and transistors and output rectifiers distance should be very close, high frequency for flowedCurrent, it is easy to heat up, .so ask these capacitors with high frequency and low loss and high temperature characteristics. In humidity and salt spray, Aluminum Electrolytic Capacitor shell corrosion occurs, the capacity of drift, the leakage current increases, so the ship and humid environment, it is best not to .use Aluminum Electrolytic Capacitor. Due to the space particle bombardment, electrolyte will explode, Aluminum Electrolytic Capacitor also does not apply to aerospace electronics devices. Tantalum Electrolytic Capacitor temperature and frequency characteristics of a good, high and low temperature resistance, long storage time, performance .stable reliable, but tantalum Electrolytic Capacitor heavier, volume ratio low, not high pressure and high pressure varieties (> 125V) less, which is very expensive. About Derating design: electronic components of basic failure rate depends on work stress (including electrical, .temperature, vibration, shock, frequency, speed, crash, etc.). In addition to individual low stress failure of components, the other is expressed as the higher the stress of work, the higher failure rate. In order to reduce the failure rate .of components, so the circuit design is Derating design. Derating, in addition to reliability, regardless of size, weight, cost and other factors. Different devices have different Derating standard <br> The practice shows that most of the electronic components of basic failure .rate depends on electrical stress and temperature, thus reducing the amount also largely control both stress that the following is a common component of switch power Derating factor: ① resistance power Derating factor in 0.1 ~ 0.5. ② diode power Derating factor in 0.4 following, reverse .voltage in 0.5 ③ LEDs below..

【 Weak current College 】 refrigeration oil selection and cautions 】

1. refrigeration oil selection principles 1, depending on the compression type to choose the compressor lubricating oil freezer has a piston, screw and centrifugal three types, the first two lubricating oils and compressed refrigerant direct exposure, taking into account the lubricant and the interplay between the refrigerant. Centrifugal oil used is used to lubricate the rotor bearings, according to the size of the load and speed or selection N32. turbine oil N46 2, according to the type of refrigerant selection of lubricating oil and lubricant for refrigerant direct contacts, to consider the interplay between the two. As a class of freon refrigerant can be dissolved in mineral oil, thus chosen lubricant viscosity grade, should be better than using insoluble high a level of refrigerant to prevent oil is diluted does not guarantee that the lubrication. Also note that mixed with a small amount of oil in the refrigerant will not affect the work of the refrigeration system. Refrigeration oil of freezing point is to check the oil in the refrigerant is mixed on whether the precipitation of wax crystals jams refrigeration system quality indicators. 3, according to the choice of refrigerant evaporating temperature lubricating oil in General, the refrigerant evaporating temperature low freezer should use solidifying point lower refrigeration oil, lest the refrigerant in the refrigeration system with a lubricant condensation in the throttle and the evaporator, the impact of refrigeration efficiency. Use ammonia as a refrigerant in the refrigeration, freezing of the lubricant should be lower evaporation temperature. Made with freon refrigerants, lubricants of freezing point may be slightly higher than the evaporation temperature. 4, the working conditions under refrigeration lubricant selection of large and medium-sized multi cylinder, high-speed (piston average speed 3m/s and over), load a large freezer should use viscosity larger VG46 or VG68 or VG100 refrigeration oil. Exhaust gas temperature at 145 ° c or higher load freezer use VG68 or VG100 refrigeration oil. Small, micro-or low-speed (piston average speed not higher than 2m/s) freezer available VG22 or VG32 refrigeration oil. 2. refrigeration oil usage considerations 1. selected oils, lubricating oils, flash point than the freezer of the exhaust gas temperature high 25 ~ 30 ℃. 2. refrigeration oil shall not be mixed in the animal and vegetable oils. As a result of animal and vegetable oil and coolant generates sediment, clogging recycling line. 3. use, when refrigeration oil viscosity decrease 15%, a significant change in the color should be replaced in a timely manner. Or to work time and acid value change to limits: General compressors or freezer bearing lubrication system, the year 1000 ~ 2000 hour oil change, oil change values for the limits to the acidic 0.3 ~ 0.45 mg KOH/g. 4. before changing the new oil, lubricating oil drop in old, carefully clear set net tank of oil and impurities, clean, and then join the new oil

【 Weak current College 】 permeated, leaching welding low foaming, Peel strength and countermeasures 】

Rigid circuit board PCB and FPC flexible circuit board production process are often encounter the following issues:

A, line section appear dry or wet processed there in etching line, the lateral erosion corrosion, causing sunken line width or line unevenness. the reason for no and dry and wet film material choice inappropriate, improper, exposure parameters exposure machine performance side. sprayer developer, etching segment, related parameters adjustable unreasonable, inappropriate drug concentration range, transmission speed of improper series may be causing the problem, however we often found after checking the above parameters and related equipment performance is not an exception, however doing Board still appear line too erosion, corrosion, and other issues. alcove what?

Second, in making PCB pattern plating, PCB, FPC Terminal surface treatment such as immersion gold, gold, Tin, Tin of electro-technology, such as when we processed often found out of plates in the dry and wet film edge or solder mask layer edges appear permeated phenomenon, or the majority of the Board, or some part of the Board, in either case will cause unnecessary scrap or bad for the back section processing unnecessary trouble, and eventually scrapped, distressing! the reason analysis we usually think of is the dry and wet film parameters, material performance problems; solder mask as hard Board ink, soft Board covering film, or in print, press, curing, section problems. Indeed, where each may cause this problem to occur, then we also confused by checking the above procedure did not question or problem is solved, but it still appears that permeated. whether there is any reason didn't look it up?

Third, the circuit board in the shipment of Tin on do before trial, the customer, of course, in use at the Tin soldering components. possible two stages will occur, or in a certain stage occurs when the wicking or solder, solder blistering and peeling substrate. do tapetest ink peeling strength, tensile Tester soft plate cover film peeling strength when it appears clear ink can be split or overlay membrane Peel strength is insufficient or no problem. this kind of problem clients especially do precision SMT customer is absolutely unacceptable. solder mask layer once encountered the bubble welding peeling will cause you to lose precision placement primitives. caused a significant loss of client components and tardy. circuit board factory at the same time will face deduction, feeding, and even the loss of customers, and other great damage then we usually encountered such problems will begin in a few aspects? we usually go to analysis is not solder mask (inks, mulching) material; it is not the screen printing, laminating, curing stage; is it a problem of electroplating solution?, and so on ... so we usually order the engineers make sure these section a a find, and we will also improve the thought is not the cause of the recent weather?, humid? sheet moisture (substrate and solder mask are susceptible to moisture) after a bitter, how many can reap some effectiveness issues was temporarily under the surface of the solution, so inadvertently such problems took place, what causes the problem that can happen? ' section obviously has been checked in the improvement is what is not. Note?

For PCB, FPC above belong to a wide range of industry challenges we confused a lot of testing and research, finally found produces line, alloying, tiered, blistering, peeling strength shortage was an important reason is that the former treatment section. includes dry-wet membrane pre-treatment, solder plating before processing, such as section prior to the treatment of partial. here, perhaps, many people cannot help but to laugh industry. pre-treatment is the simplest, acid cleaning, degreasing, micro-etch. which drops, as before, parameters, and performance, the industry's many technicians are clearly. circuit board production process involves a large number of complex surface treatment solution, such as heavy electrical copper, electric power, Tin, gold, sink, OSP, etching, etc. these complex processes in most cases, the process engineer can choose to go in-depth research, analysis, and strive to master these techniques as upgrading their technological capacity breakthrough. While most factories also to pay standard as an engineer, performance assessment and treatment before the PCT standard piece basically little engineer staff to carefully study the. either directly from the vendor to purchase the finished product, except the oil, acid wash their own inhibitor with dilute sulfuric acid as pickling. and even many plant micro-etch also own distribution, either with a sodium, ammonium system (formula became known), or purchase a hydrogen peroxide stabilizers themselves with hydrogen peroxide-sulfuric acid system. except oil through the purchase of vendor products except purchasing oil or oil powder dilution. According to our survey found that many manufacturers do not know from the root up pretreatment of the liquid in the subtle effects, or is it a key role, focused only on the surface look if oil segment, you may have always thought that the plate surface grease, finger print can be dropped, invisible for degreasing OK, everyone knows except oil technology on board, not only will have on the copper surface depths with oil peeling, while more important drug to be split down to the molecular decomposition of oil so that parties can fall. on Board did not form a second pollution. market now for sale except oil, oil meal, usually only contain ingredients except oil, rust, and other components such as photoresist, surfactants, emulsifiers, and other important groups are divided into lower costs did not increase; even the vendors of prescription purchase from elsewhere, are not understanding the role of each component, let alone study, or in combination with the actual process of circuit board needs leveling joinedthe effective component. This effectively many PCB factory uses degreasing agent is not applicable to the printed circuit board industry-specific, and degreasing agents are generic to the hardware, the traditional mineral processing industry, except oil. how to achieve this product good oil effects, the pan with the naked eye watching degreasing effect is good, actually? we power microscope or oil film test can find a large number of small oil molecules attached to the plate surface. how effective such treatment cannot be guaranteed follow-up production corrosion layer, solder mask layer, Terminal surface treatment, good adhesion, Peel strength, solderability, etc. must be performance of efficacy and stability it is particularly serious. is our micro-etch this piece of PCB industry awareness. micro-etch technique actually remove copper 1.Surface rust, oxidation layer, and other foreign bodies; 2. uniform coarsening copper surface, the formation of micro-bump, the macro-level coarsening layer. achieve rate stable coarsening effect .3. activating the copper surface, and have a short period of resistance to corrosion in gas and liquid, ensure follow-up surface processing of operability .4, low peroxide and sulfuric acid content, prevent liquid Flash-boiling and forming polymer organic residues Board., actual production, that mixes or purchased most of the micro-etching fluid as the micro-etch Etchant. considers that only the Board surface rust stain removal of foreign bodies, revealing new copper surface is achieved the effect of micro-etch. fact? our micro-etch that mixes in peroxide as hydrogen peroxide, sodium persulfate, ammonium, strong acids such as sulphuric acid to achieve the effect of the content is high, such as peroxide content reaches 120 and 150 grams/liter, sulfuric acid content of more than 5 per cent, such high concentration is the micro-etch into a substantial copper etching, bite inhibition, and because no regulators, bite inhibition is not a superficial depth, the caused the plate surface treatment results are inconsistent, to the second rework that cause serious bite copper layer etching, after section processing cannot be done, resulting in scrap. many with hydrogen peroxide systems also make that added hydrogen peroxide stabilizers can achieve uniform-inhibition of common misconceptions. hydrogen peroxide stabilizers for Suppression of hydrogen peroxide decomposes into too quickly, and will not be able to play the role of uniformity are not actually used for circuit board £ ® professional micro-inhibitor it should with low foam surfactant, wetting agents, organic complexing agents, micro-set Agent to resist and so on many kinds of additives, thereby enabling peroxides, sulfuric acid, biting rate too high, the reaction products of higher primary components in minimizing, and make the liquid more stable, in addition to the more basic features of rust and can even stable coarsening of copper surface, forming a flat and smooth surface of macroscopic (favor Terminal surface appearance), no color difference, peculiar zone or point; at the same time, the micro to achieve uniform and consistent punch and coarsening layer (conducive to subsequent corrosion wet film, solder mask layer processing), actually rely on antioxidants and strong acids and cannot increase the ideals of copper surface roughening area, to be joined to the active agent, wetting agent, etc to achieve a good depth coarsening effect, increase the copper surface roughening area, after upgrading from surface processing of adhesion and peeling strength £ ® after perfecting and improving the circuit dedicated micro-etch liquid whole should achieve: liquid without Flash-boiling, the formation of by-products without polymer, good rust contamination, good appearance uniform flat, depth coarsening of copper surface, corrosion of copper in small plate surface appearance. achieve smooth solder or when combined with strong coating processing, etc.

With the circuit board to the ultra-thin copper type conversion, we increasingly need a corrosion of copper in smaller micro-etch liquid (while keeping the rust and coarsening effect).

With the circuit board line accuracy requirements are getting higher and higher, we increasingly need a pretreatment effect better oil, slightly altered fluid. to ensure that the corrosion layer (dry film) resistance to penetration.

As PCB Terminal surface treatment looks increasingly high demands, we need to introduce high-quality pretreatment.

As the surface welding to lead-free transition, circuit board need to withstand welding temperature higher and higher, on the surface of the solder mask layer of thermal shock capacity increasingly demanding, on Terminal surface treatment and solder mask layer (inks, film), Peel strength, and substrate binding force requirements of copper is getting higher and higher, we need a better effect of pretreatment for protection.

With the circuit board industry competition becoming increasingly fierce, we need to improve our processes so that product yield increase, in order to obtain profit growth point. quality of medicine will no doubt be low-cost help us a lot.

Printed circuit board industry front such as the United States, Japan, Korea, Taiwan has long been valued and enable next-generation pretreatment. make the products more competitive, performance stability brought up by small, formerly set out to ensure that the overall process for handling stability.