Sunday, March 27, 2011

【 Weak current College 】 freezer energy introduction 】

Cold energy dissipation factor mainly include the performance of the refrigeration system, refrigerant selection, compressor, condenser and evaporator selection, cold storage size and layout, a cold-insulation layer type and thickness, cold storage and cargo, freezer door of heat insulation, etc. to improve refrigeration efficiency all factors should be taken into consideration. Energy-saving way to reduce the energy consumption of refrigeration storage is usually divided into two parts: 1) to reduce cold room cooling load, (2) cold storage equipment selection. An energy-saving, freezers fruits and mini refrigerator is comprised of the Library Board cold storage, refrigeration units, evaporator, etc. in good advance manufacturing factory, in the field of origin of agricultural products to be assembled after installation of cold storage or civil cold store or freezer half-half Assembly, civil engineering and reservoir capacity is generally less than 200m3 for fresh cold storage. Classification by design temperature, fruit thinning mini freezer temperature freezer belonging to. Mini Freezer by the refrigeration system, the Treasury, control systems, etc. Effect of freezers and cold energy-saving measures 1. cold storage building envelope refrigerator running through the envelope's chilling and cold storage building envelope unit proportional to heat flow. Therefore, it should be more in reducing cold storage of cold storage building envelope unit heat flow indicators. To reduce the heat flow rate envelope unit, a thermal conductivity of the insulating material, the second is to thick envelope layer. But in General should not be too thick thickness, otherwise the increase in construction costs and waste of space. Therefore, to the appropriate thickness range select insulation. Typically require insulation thermal conductivity of small, low water absorption, high cost of low-temperature performance is good, can not be too high. Common cold insulation materials have rice husk, polystyrene foam, polyethylene-cool rigid foam, etc. Rice husk using convenient, but the smaller thermal resistance, moisture absorption, and the dosage, the library of construction involved a time-consuming conversion actually cost less polystyrene; polystyrene foam manufacturers, acquisition, thermal resistance is large, affordable, easy to install; a polyurethane rigid foam thermal insulation performance of the biggest, best, but the price is high. 2. cold storage building envelope of moisture and cold storage building envelope geqi to take moisture geqi measures are also necessary, this will make the insulation of heat preservation performance variation. This is a cold storage warehouse in just starting using thermal insulation properties and good, but with time and poor insulation. Due to the high temperature steam from the low-side, side, moisture-proof geqi layer should be set at a high temperature insulation. 3. cold evaporation pressure and temperature evaporation temperature and evaporation pressure corresponds to know after evaporation pressure can be obtained by consulting evaporation temperature. Temperature in cold storage warehouse under certain conditions, the temperature difference (evaporation temperature and the temperature differential of the coffers) reducing evaporation temperature can increase proportionally, freezer refrigerator cooling capacity will be increased, improved cycle efficiency, the saving energy. 4. freezer defrosting operation in General, when the evaporator surface of frost layer on the air resistance is not significantly, through the evaporator air flow rate is not reduced, the effects of frost layer is not serious, not defrosting; when the air flow is significantly reduced, should conduct a defrosting. Air humidity increases, evaporator temperature and the temperature of cold storage library, easier on the evaporator, the combination of frost and freshness, to adopt the package of frozen fruits and vegetables can reduce energy consumption, reduce dry evaporator defrosting times, actually also played the role of cold storage and energy saving. 5. cold storage temperature and cold storage warehouse utilization of different fruit and vegetable storage temperature is different, each kind of fruits and vegetables are also suitable for the storage temperature range. Without prejudice to the fruit and vegetable quality, energy-saving refrigerator should use a higher storage temperature. High temperature of cold storage library, and evaporation temperature refrigeration system also increases, refrigerator cooling capacity will increase, the course also cycle efficiency has improved. Improving cold storage library temperature more importantly can also reduce the body through the library of heat to the outside. Energy-saving refrigerator warehouse utilization is real fruits and vegetables account for volume and effective volume ratio of the Treasury. For micro-cold storage capacity utilization generally 0.3, certainly would not be too high, otherwise a cooling problems. For the storage of fruits and vegetables of volume change is large, it should be split into two or more freezer cold storage rooms. In addition to selecting the right storage cycle, the energy of the freezer is self-evident. 2. frequency technology for refrigerated cold storage and energy-saving light cold storage consumption of 80% of enterprises is the refrigeration system, and refrigeration compressor power consumption accounted for 60%, therefore the compressor by matching motor energy saving significance of the more significant. Cold storage design, generally based on the annual maximum mechanical load condition determine equipped machine, to meet the demands of heat load peaks in actual operation, however, due to the presence of food cold and other changes in the factors that tend to design the matching of refrigeratory compressor full load run short, low load and run a long time, that most of the time is less than the compressor design load condition run, in our country, the prevailing cold compressor motor load is low. Third, mini refrigerator, micro-energy-saving refrigerator for agricultural production in China's major business management models and rural family economic and technical standards, the development of a simple operation, reliable performance, results and good storage facilities, has obtained the national patent and the 8th China patent new technology and new products Expo Special Gold Award. It can be widely applied in the fruit, vegetable, food, flowers and other agricultural and sideline products and herbal medicine, food, chemical raw materials storage and cooling, suitable for urban and rural families in North and South and collective use, is regulated and vegetable season, local resources for the economy for the carrier.

Refrigeration equipment is the most micro-energy-saving refrigerator from the national vital part of agricultural preservation Engineering Technology Research Center (Tianjin) green star preservation equipment co., Ltd design and manufacture. Green star company mainly development and production and is suitable for rural families, wholesale market, supermarket dedicated supporting refrigeration equipment, frozen freezer equipment, installation of cold storage, and assume various mini refrigerator, large and medium-sized refrigerator, air conditioned cold storage project.

Mini Freezer equipment main features:

(1) mini refrigerator refrigerant charging and debugging in the factory after rigorous testing is complete,At the same installation convenient, just the indoor unit and the outdoor unit with pipe connection, power it can work.

(2) mini cold storage and refrigeration units imported hermetic compressor, main control components can also be used abroad products, so running safe and reliable, trouble-free running time is long.

(3) mini refrigerator automatic control system adopts microcomputer control, temperature control, easy operation, accurate unit with automatic and manual-operation function, there are a variety of automatic protection devices at the same time equipped with electronic temperature display, convenient user observation on the temperature in the cold storage library.

(4) mini cold storage units using heat or electric defrost, defrosting time is short, defrost temperature fluctuations during library.

Mini refrigerator most common specification has two kinds: 90m3 and 120m3 volume, building investment General 1.5 ~ 2.0 million, according to the design of miniature and energy-saving cold storage warehouse, construction elements for cooling down speed, thermal insulation properties, cold storage, temperature fluctuations in the small library empty Library General post within 48 hours, the temperature of cold storage library may be 20 ° c to 0 ° c; fruit early pre-cooling and cooling stages, equipment, power consumption is generally 40 ~ 50 degree temperature stability, cold storage library the day after the power consumption is only 7 ~ 8 degrees, the North in winter can be cold source ventilation, monthly electricity consumption is very low.

【School】 SCM weak c language tutorial --- Lesson: variable】.

<br> class variables mentioned in the program execution is a value to the process of changing its volume. .To use variables in the program must first use the identifier as a variable name, and pointed out that the type of data used and the storage mode, so that the variable distribution system to compile the corresponding storage space. .The format of a variable defined as follows: <BR> [store type] data type [memory type] variable format in the definition watch <BR> data types and variables in addition to watches is necessary, the other is optional. .There are four storage types: Auto (auto), external (extern), static (static) and registers (register), the default type to Automatic (auto). .The specific meaning of these storage types and usage, will be the seventh class "variable stores" in the further study. .<BR> And here is the data type and the fourth lesson we learned the name of the definition of data types is the same. .Illustrates the data type of a variable can also select the memory that the variable type. .Memory type is specified in the variable description of the hardware system in the C51 used in the storage area, and accurate positioning at compile time. .Table 6-1 is KEIL uVision2 can identify other memory types. .Note that only in the low AT89C51 chip RAM 128, is located in the high-80H to FFH 128-bit chip in the 52 to be useful, and the special register address and overlap. .Special register (SFR) of the address table see Appendix II list of special function registers AT89C51 memory type <? XML: NAMESPACE PREFIX = O /> <O:P> </ O: P> Description <O:P> </ O: .P> data <O:P> </ O: P> direct access to internal data memory (128 bytes), access to the fastest <O:P> </ O: P> bdata <O:P> </ O: .P> bit-addressable internal data memory (16 bytes), which allows mixed bit and byte access <O:P> </ O: P> idata <O:P> </ O: P> Indirect access to internal data memory .(256 bytes), which allows access to all internal address <O:P> </ O: P> pdata <O:P> </ O: P> page to access external data memory (256 bytes), with the MOVX @ Ri .instruction access <O:P> </ O: P> xdata <O:P> </ O: P> external data memory (64KB), with the MOVX @ DPTR instruction accesses <O:P> </ O: P> code .<O:P> </ O: P> program memory (64KB), with the MOVC @ A + DPTR instruction accesses <O:P> </ O: P> <BR> Table 6-1 Memory types of memory types if omitted, .system will compile the model by SMALL, COMPACT, or LARGE memory type required to specify the default storage area variables. .No matter what storage mode can declare variables in any storage area 8051, but the most commonly used commands, such as loop counters and queues on the internal data area index can significantly improve system performance. .Also to point out that the variable storage types and storage types are completely unrelated. .<BR> SMALL memory model variables and all functions on the 8051 system of local data segment of the internal data storage area that makes access to data very fast, but the SMALL memory model of the address space is limited. .Writing small applications, data variables and data on the internal data memory is good because the access speed, but in the larger application data area's best to store a small variable, data or frequently used variables .(such as cycle counting, data index), and large data storage area is placed in the other. .<BR> COMPACT storage mode functions and procedures of all variables and local data segment positioning system in the 8051 external data store. .External data memory can have up to 256 bytes (a), in this mode, external data storage area of the short address with @ R0/R1. .<BR> LARGE storage mode all functions and procedures of the variables and local data segments are located in the 8051 system, the external data area of external data area can have up to 64KB, which requires access to data with the data pointer DPTR. .<BR> Mentioned earlier briefly mentioned sfr, sfr16, sbit variables defined in the method, let's take a closer look again. .<BR> Sfr and sfr16 microcontroller 51 can directly define the special register is defined as follows: <BR> sfr special function register name = special function register address constant; <BR> sfr16 special function register name = SFR address constant .; <BR> AT89C51 we can define the P1 port <BR> sfr P1 = 0x90; / / defined in P1 I / O port, the address 90H <BR> sfr be followed by a key name to be defined, can be arbitrarily selected, .But to meet the naming rules for identifiers, the name has some meaning, such as the best port P1 P1 can name, this program will become a lot of good reading. .After the equal sign must be a constant, does not allow expressions with operators, and the constant need to address the special function registers within the scope of (80H-FFH), specifically to see the related tables in the appendix. .sfr is to define the 8-bit special function register is used to define the sfr16 16-bit special function registers, such as the 8052's T2 timer, can be defined as: <BR> sfr16 T2 = 0xCC; / / defined here 8052 Timer 2 .address T2L = CCH, T2H = CDH <BR> sfr16 defined by the 16-bit special function register, after the equal sign is its low address, high address low address must be located above the physical. .Note that Timer 0 and 1 can not be used for the definition. .<BR> Sbit defined bit-addressable objects. .Such as access to certain special function registers in. .In fact, this application is the regular use of the mouth, such as P1 to access the first two pins P1.1. .We can according to the following method to define: <BR> (1) sbit bit variable name = bit address <BR> sbit P1_1 = Ox91; <BR> this is the bit absolute address assigned to bit variables. .Sfr sbit with the same bit address must be located between 80H-FFH. .<BR> (2) Sbit bit variable name = name ^ bit special function register location <BR> sft P1 = 0x90; <BR> sbit P1_1 = P1 ^ 1; / / first define a special function register names and then specify the name of the variable bit .location addressable bit <BR> When special function register in this way can be used when <BR> (3) sbit bit variable name = byte address ^ bit position <BR> sbit P1_1 = 0x90 ^ 1; < .BR> In fact, this method and 2 are the same, only the address of the special function register directly with the constant said. .<BR> C51 memory type is provided in a bdata memory type, this is the bit-addressable data memory, in the MCU can be bit addressable area, you can address the requirements can be recorded in the data bit is defined as bdata, .such as: <BR> unsigned char bdata ib; / / recorded bits in the address area can be defined ucsigned char type variable ib <BR> int bdata ab [2]; / / define the array of bit-addressable area ab [2], .These are also referred to as addressable digital object <BR> sbit ib7 = ib ^ 7 / / sbit definitions with the keyword bit variable bit-addressable objects independent access to one of <BR> sbit ab12 = ab [1] ^ .12; <BR> operator "^" followed by the bit position of the maximum depends on the type of the specified base address, char0-7, int0-15, long0-31. .<BR> Lesson we use the circuit below to practice the knowledge about the lesson. .Also do some simple experiments Marquee, the project called RunLED2. .Procedures are as follows: sfr P1 = 0x90; / / There is no predefined file, <BR> sbit P1_0 = P1 ^ 0; / / but their definition of a special register <BR> sbit P1_7 = 0x90 ^ 7; / / before we use .predefined document was in fact the role of <BR> sbit P1_1 = 0x91; / / P1 ports are defined here, and P10, P11, P17 pin void main (void) <BR> {<BR> unsigned int a; <BR> .unsigned char b; <BR> do {<BR> for (a = 0; a <50000; a + +) <BR> P1_0 = 0; / / lit P1_0 <BR> for (a = 0; a <50000; a + + .) <BR> P1_7 = 0; / / lit P1_7 <BR> for (b = 0; b <255; b + +) <BR> {<BR> for (a = 0; a <10000; a + +) <BR> .P1 = b; / / Marquee with b values do tricks <BR>} <BR> P1 = 255; / / off on the P1 LED <BR> for (b = 0; b <255; b + +) < .BR> {<BR> for (a = 0; a <10000; a + +) / / P1_1 flashing <BR> P1_1 = 0; <BR> for (a = 0; a <10000; a + +) <BR> P1_1 = 1 .; <BR>} <BR>} while (1); <BR>}.

Weak current College】 【】 LED specifications.

<br> <br> 1. Interior Panel series indoor display area of the dozen m², point density is high, in direct sunlight or lighting environment uses, see distance within a few metres away, the screen does not have a waterproof seal. Under .control and display of colors that can be divided into the following: • indoor full color video screen ★ self-developed pixel correction technology to ensure the uniform between points. <br> ★ Display panel of the luminous points with cylindrical head of light-emitting .diode, tested, <br> Full view of longitudinal horizontal can reach 150 degrees. <br> ★ Constitute light plate reflector produced by opening and luminous point seamless anastomosis, finished product can be <br> Do minimal surface height error. <br> .¡ .Ï using light-emitting diode, led brightness light-emitting chip brightness of 6-8 times. <br> ★ Light-emitting diode thermal major loss from metal pin, determines the display panel <br> Excellent cooling performance. <br> ★ .Bad light-emitting diodes can be individually replaced, does not affect other led, <br> Reduce maintenance costs. <br> ¡ .Ï using state-of-the-art video control system, display color gorgeous clear. ★ Major technical parameters-color RGB (full color) pixel diameter mm] [2600 5.00 8.00 <br> Pixel pitch Gordon 7.62 10.00 s mm <br> .Pixel composition 1R1G1B 2R1G1B virtual pixels <br> Unit Panel number] [point s 32 × 32 × 32 16 <br> Unit panel size] [245 × 245 mm section 320 × 160 <br> Unit Panel weight 850 gs 1100 s <br .> Physical pixel density/m2] [point 2600 17200 10000 <br> Virtual pixel density/m2] [point 2600 16384 40000 <br> Peak power consumption], [W/m2 s 850 750 <br> Average power consumption], [ .W/m2 s 350 320 <br> Weight Kg/m2] [2600 <<36 36 <br> The Visual angle of 150 ° horizontal <br> Vertical Visual angle of 150 ° <br> Maximum brightness] [cd / .m2 s 1700 800 • indoor dual-color video display screen ★ module using the large product, full screen brightness and luminous uniformity is good. <br> The system is stable and mature, simple installation without debugging, the failure rate is very low. .<br> ¡ .Ï using state-of-the-art video control system, display color gorgeous clear. ¡ .Ï main technical parameters of the base RG (red, green, double-color) pixel diameter mm] [2600 3.75 5.00 <br> Pixel pitch Gordon 4.75 7.62 s mm <br> Pixel composition 1R1G 1R1G <br> Unit Panel number 64 × .32 (or 80 × 32) 80 × 32 <br> Unit panel size mm ss <br> 306 × 153 (or 382 × 153) <br> 612 × 245 <br> Unit Panel weight 800 gss 1500 <br> Pixel density ./ m2] [point s <br> 43000 17200 <br> Peak power consumption], [W/m2 s 700 350 <br> Average power consumption], [W/m2 s 300 200 <br> The Visual angle of 150 ° .<br> Communication distance (m) 100 (no relaying) <br> ● Indoor monochrome screen ★ display module using the large product, full screen brightness and luminous uniformity is good. <br> The system is stable and mature, simple installation without .debugging, the failure rate is very low. <br> ¡ .Ï according to different requirements, use the synchronously or asynchronously. ★ Major technical parameters color monochrome <br> Pixel diameter mm] [2600 3.0 3.75 5.00 <br> Pixel pitch distance mm side 4.0 4.75 7.62 <br> Pixel composition 1R 1R 1R < .br> Unit Panel number] [point s <br> 64 × 64, 32 × 32 × 32 80 <br> Unit panel size mm ss <br> 153 612 × 306 × 245 <br> Unit weight gss Panel <br> 700 .900-1500 <br> Pixel density/m2] [point s <br> 62500 43000 17200 <br> Peak power consumption], [W/m2 s <br> 350 200 500 <br> Average power consumption], [W / .m2 s <br> 350 200 100 <br> The Visual angle of 150 ° <br> Communication distance (m) 100 (no relaying) <br> 2. semi outdoor screen series half-outdoor screen consists of general use single lamp light .-emitting points, suitable for high brightness and waterproofing of the environment, for example: eaves, display Windows, light strong lobby, etc. The dot pitch is generally around 7.62mm-10mm; glow color normally single-red or red / green dual .-color; control according to application requirements, there are asynchronous, synchronous graphic, video, etc. ★ Major technical parameters color monochrome / dual-color pixel diameter 5 mm] [2600 5.00.00 <br> Pixel pitch Gordon 7.62 10.00 s mm .<br> Pixel composition 1R 1R <br> Unit Panel number] [point s 80 × 32 × 32 16 <br> Unit panel size] [612 × 245 mm section 320 × 160 <br> Unit Panel weight 1000] [Gordon 1700 .g <br> Pixel density/m2] [point 2600 17200 10000 <br> Peak power consumption], [W/m2 s 400 300 <br> Average power consumption], [W/m2 s 250 200 <br> Horizontal Visual angle .60-70 ° <br> Vertical Visual angle 45-60 ° <br> Maximum brightness] [cd/m2 s 3000 1800 <br> 3. outdoor screen series outdoor screen area for more than ten square meters in General, higher brightness, .you can use the environment in the sunlight, view distance in general than ten metres away, the screen has a waterproof seal. Under control and display of colors that can be divided into the following: • outdoor full color video screen ★ display panel of the .luminous points using a solid color, ultra-high brightness led, display <br> Effect real nature. <br> ★ Light plate for cabinet structure, easy installation, look flat. <br> ¡ .Ï using state-of-the-art video control system, display color gorgeous clear. ★ Major technical parameters-color RGB (full color) pixel diameter mm] [2600 15.00 18.00 <br> Pixel pitch 25 mm side 20 s <br> .Pixel composition 2R1G1B 2R1G1B <br> Unit Panel number] [point s <br> 32 × 32 × 16 16 <br> Unit panel size mm ss <br> 640 x 320 800 × 400 <br> Unit Panel weight 1000 1500 gss < .br> Pixel density s 2500 s point/m2 1600 <br> Peak power consumption], [W/m2 s 1000 800 <br> Average power consumption], [W/m2 s 380 350 <br> Weight Kg/m2] [ .2600 <<40 42 <br> Horizontal Visual angle of 70 ° <br> Vertical Visual angle 45 ° <br> Maximum brightness] [cd/m2 s 7000 800 • outdoor dual-color video screen ★ lamp plate for cabinet structure ., easy installation, look flat. <br> ¡ .Ï using state-of-the-art video control system, display color gorgeous clear. ¡ .Ï main technical parameters of the base RG (dual color)], [2600 mm pixel pitch <br> 11.5 16.0 22.0 <br> Pixel composition 2R4G 2R1G 2R1G <br> Unit Panel number] [point s <br> 32 × 32 × .32 and 16 × 16 16 <br> Unit panel size mm ss <br> 368 × 184 512 × 256 704 × 352 <br> Unit weight gss Panel <br> 1000-1500-2300 <br> Pixel density/m2] [ .point s <br> 7600 4096, 2048 <br> Peak power consumption], [W/m2 s <br> 800 600 500 <br> Average power consumption], [W/m2 s <br> 300 250 150 <br> .The Visual angle of 70 ° <br> Communication distance (m) 100 (no relaying).

Weak current College】 【RF engineer of specific work content】.

1. circuit system analysis, some communications equipment company project, RF engineers need to be responsible for the entire RF system circuit for system analysis, guidance system design specifications, allocation unit module specifications, standardized EMC design principles, made with attachment functionality and performance requirements, and so on; 2. Circuit design, including block diagram design and circuit design, RF engineer must have basic skills. This is by design of serves, and how to implement system design goal, and that is the purpose of circuit design, it is the device selection assessment of "cause", because the process of designing circuit is also a device selection process. 3 device selection and evaluation, in order to achieve the circuit indicators requirements, select the appropriate device is essential to this process actually and circuit design is at the same time. How to select the appropriate devices, in comparison, the same type of device in which a more appropriate design of our products? cost, performance, technology requirements, packaging, supplier quality, delivery, etc., are factors to be considered. 4. the software emulation, ADS, MWO, Ansoft HFSS or, anyway, CST, you should always be one or two simulation software for use. Simulation software will not let your design to achieve 100% accuracy, but will not allow you to deviate from the basic directions of design, at least they are qualitative simulation of regard is accurate. So we must learn to use one to two or more simulation software, its basic function is to allow you to qualitative analysis of your design, the error is always there, but it can strengthen your confidence. 5. PCB LAYOUT, the principle can be compared to the theoretical foundations, 000 applications could only a theory, there are also several products may have only one schematics, wiring as long as it's not the same, like mobile phones, with a cell phone plan many companies to design, schematic is the same, but different company cloth out of PCB, a look, a performance also have differences. Performance differences, in fact, the PCB LAYOUT differences. Meet the requirements of the PCB, its layout and wiring combine performance, features, technology, EMC, etc. Therefore, the PCB LAYOUT is also a very important skills. 6. Debug analysis, debugging and commissioning. Production debugging is mandatory, research and development product debugging will focus on identifying problems and resolve issues. Debugging is a summary and accumulation of experience, is not to say that accumulated through debugging, and debugging experience is accumulated by debugging design experience; many problems may at design time is not found, then the discovery through debugging, you know that in the future at design time how to avoid these problems, how to improve these problems. Debugging is also a theory of practice the most effective way, we can use the debugging process to qualitative understanding of theoretical knowledge. 7. test, test is for debugging, debugging a service is to provide design services (design for market services). RF engineer must be familiar with various RF test instruments, spectrum analyzers, network analyzers, signal sources, oscilloscopes, power meter, noise coefficient measuring instrument, tester, etc. Does testing would be very difficult to effectively debug, cannot find the problem how to be improved? so don't underestimate the testing technique, in fact, looking at the RF foreign enterprises, real artists are from design to test technology, in the middle of reasons worthy of our consideration. 8. if available, your parents force parents to do more grassroots work, can own welding welding on your own, you cannot debug when someone in your stay to give you the edge for capacitance and inductance change? so don't grads are looked down upon, capable of welding's own welding.

【 Weak current College 】 infrared thermometer measurement technology as well as the selection guide 】

Infrared temperature measurement technology in the production process, product quality control and monitoring equipment online troubleshooting and security protection and saving energy has played an important role. In the last 20 years, non-contact infrared thermometer is technically is the rapid development, the performance is constantly improving, growing variety features are increasing all the time, the scope is also continually expanding market share year on year growth. Compared to contact temperature measurement, infrared temperature measurement with fast response times, contactless, use safety and long life and other advantages. Non-contact infrared thermometer including portable, on-line and scan-three series, and equipped with various options and computer software, and each series and the various models and specifications. In different specifications of various types of thermometer, proper selection of infrared thermometer model to the user, is very important.
Infrared technology is the ninth country--key promoting project license on technology, infrared detection is an on-line monitoring (without interruption)-high-tech detection technology that sets imaging technology, computer technology, image processing technology, by receiving objects emit infrared (IR), the thermal image displayed on the screen to determine accurately the object surface temperature distribution with accurate, real-time, fast, etc. Any object as its own elements of movement, and radiates infrared heat energy to the surface forming a certain temperature, commonly known as "thermography". Infrared absorption of diagnostic techniques it is through this infrared radiation energy, detect device surface temperature and temperature field of distribution, thus determining device heating. The current application's Red Waizhen technology test equipment, such as infrared pyrometer, infrared TV, infrared, etc. Like infrared TV, infrared camera and other equipment using thermal imagingtechnology will see "thermography" into a visible image, the test results in an intuitive, high sensitivity, which can detect the device minor thermal state change that accurately reflects the internal and external heating, high reliability and potential for discovery of devices are very effective.
Infrared diagnosis technique on the early failure of electrical equipment and insulation performance to make reliable forecasts, the traditional electrical equipment preventive test maintenance (prevention trial is 50 's introduction of the former Soviet Union standards) to predict the State maintenance, this is the modern power enterprise development direction. Especially now, ultra high voltage large unit for the reliable operation of power systems, power grid stability, put increasingly higher demands. With the continued development of modern science and technology become increasingly mature and perfect, the use of infrared condition monitoring and Diagnostics technology with distance, no contacts, no samples, no disintegration, and accurate, fast, intuitive, real-time online monitoring and diagnostics of electrical equipment most failures (almost cover all electric equipment in various fault detection). It attracted the attention of the electric power industry at home and abroad (foreign late 1970s universal application of an advanced condition-based maintenance system), and rapid development. Infrared technology, to improve the reliability of the electrical equipment, improve operational effectiveness and economic efficiency, reduce maintenance costs are very important. Is currently in the field of predictive maintenance generally promoted a very good tool, but also make maintenance and equipment of health level to a higher level.
Using infrared imaging technology to running equipment for non-contact detection, its temperature field distribution measurement of any part of, the temperature value, the various external and internal fault diagnostics, with real-time, telemetry, intuitive and quantitative measurement, etc., used to detect power plants, substations and transmission lines running equipment and electrical equipment is very easy, and effective.
Use of thermal imager testing online electrical equipment by infrared thermography method. Infrared thermography method is the industry used to nondestructive detection, detection equipment performance and control their running state of a new technology. With the traditional temperature measurement (e.g. thermocouple, different melting point of wax tablets, placed in the measured surface or body) compared to thermal imager can be within a certain distance in real time, quantitative, online testing, the temperature of the hot spots, by scanning, you can also draw a device running temperature gradient thermography, and high sensitivity, are not affected by electromagnetic interference, easy to use site. It can be-20 ° c to 2000 ° c within the wide-range to 0.05 ℃ high resolution detection of electrical equipment for heat-induced failure revealed as conductor connectors or clamp fever, as well as electrical equipment too hot in the local and so on. Electrical equipment diagnosis of infrared technology is a new subject. It is the use of thermal effects induced by electric equipment, using special equipment gets sent from the device surface infrared radiation information, which in turn determine the device status and the nature of a defect in synthesis technology.
2. infrared theory
1672, it was discovered that the Sun (white light) is composed of various colors of light, at the same time, the Newton made a monochromatic light in nature than white light simpler famous conclusion. Use beamsplitter put sunlight (white) into red, Orange, yellow, green, green, blue, purple, and other assorted monochromatic light. 1800, United Kingdom physicist F. W. j. Xu from hot to study various shade, the discovery of infrared. He studies various shade of heat, intentionally put a uniquewindow of anechoic chamber with dark plate is blocked, and the Board had a rectangular hole, the hole of a beamsplitter. When the sunlight through a Prism, it is broken down as colored light, and use a thermometer to measure the patches of different colors in the heat. In order to compare with the ambient temperature, Xu, used in the color patches of several branch near as compared with a thermometer to measure ambient temperature. Test, he came across a strange phenomenon: in patches of red light, a thermometer, other than the indoor temperature high of numerical instructions. After repeated testing, this so-called heat up in the high temperature area, always located on the edge of light most of red light. He announced that solar radiation in the visible light line, a human eye's "hotline", this invisible "hotline" is located in the red light outside, called infrared. Infrared is a kind of electromagnetic and radio frequency and the nature of visible light, infrared light, like the discovery of human understanding of the nature of a leap, to study, use and development of infrared technology areas openOpen a new broad road.
Infrared wavelength in 0.76 ~ 100 μ m, according to the wavelength range can be divided into near-infrared, infrared, far infrared, infrared four categories, it is in the continuous spectrum of electromagnetic waves in position is in radio waves and the area between the visible light. Infrared radiation is one of nature's most extensive electromagnetic wave radiation, it is based on any objects in the General environment will produce their own molecular and Atomic motion without rules, and keep the thermal infrared radiation energy, molecular and Atomic motion more violent, more radiant energy, on the contrary, the smaller the radiation energy.
Temperature at absolute zero or more objects, because of their molecular motion and infra-red radiation. Through infrared detector will object radiation power signal conversion to electrical signals, the imaging device output signal can fully mimic scan objects correspond one-to-one with a surface temperature of space distribution, electronic systems, to display, and surface heat distribution corresponding thermography. Use this method to achieve the target distance hot image imaging and measurement and analysis.
2.1 thermal imager principle
Infrared is the use of infrared detectors, optical imaging lens and optical-scan systems (now state-of-the-art technology will eliminate the focal plane of light mechanical scanning system) accept the test objectives of infrared radiation energy distribution graph reflects infrared detector of photosensitive element, in optics and infrared detector, there is a light machine scanning mechanism (focal plane thermal imager in the absence of such bodies) to be logging objects of infrared thermal image is scanned, and focused on the unit or UV detector, the probe will infrared radiant energy is converted into electrical signals, with the enlargement process, transform, or of standard video signal through the TV screen or monitor displays infrared thermography. This kind of thermography and surface heat distribution field corresponds essentially to be logging target object sections of infrared thermal image map because the signal is very weak, compared with the visible image, the absence of hierarchy and three-dimensional sense, therefore, the actual action process to better judge the test objectives of infrared heat distribution in the field, often using some complementary measures to increase the instruments of practical functions, such as image brightness, contrast control, calibration, pseudo color paint, etc.
2.2 thermal camera development
1800, United Kingdom physicist F. W. j. Xu, discovered infrared, opened up the human application of infrared technology's broad road. In the second world war, Germany with infrared variable like tube as opto-electrical converter, developed active night vision and infrared communication equipment, infrared technology development laid the Foundation. After the second world war, first by the United States de Saram instrument company after nearly a year of exploration, development and research for first-generation military area of infrared imaging system, called infrared homing vision systems (FLIR), it is the use of optical and mechanical system under test objectives of infrared scanning. By photon detector receive two dimensional signs of infrared radiation by a series of photoelectric conversion and processing equipment, the formation of video image signals. This system, the original forms is a non-immediate automatic temperature recorder, then with the 1950s Indium antimonide and germanium doped mercury photon detector development, began to appear high speed scanning and real-time display of the target system of thermal images.
In the early 1960s, Sweden AGA developed second-generation infrared imaging device, it is in the infrared homing on the basis of the Visual system to increase the temperature of the feature, called thermal infrared imager.
Start due to confidentiality reasons, in the developed countries are also limited to military, applied thermal imaging device that night or thick curtain cloud detection in each other's goals, objectives and detect camouflage high-speed movement of the target. Thanks to the support of national funds, investment research and development costs, equipment costs are high. After taking into account the development of industrial production, combined with the practicality of industrial infrared detection feature, take compression equipment cost. Lower production costs and according to the civil requirements by reducing the scanning speed to improve image resolution, the progressive development of the civil sphere.
The mid-1960s, AGA company developed the first set of real-time imaging system for industrial use (THV), the system consists of liquid nitrogen cooling, 110V power voltage supply, weighs approximately 35 kg, the use of portability is very poor, thanks to the improvement of several generations of equipment, development of 1986 infrared camera has no need of liquid or gas, but the way in thermoelectric cooling, the available battery power supply; 1988 launched fully functional thermal imager, temperature measurement, modify, analysis, image acquisition, storage, fitness, weight less than 7 kg, instrument functionality, accuracy and reliability are significantly improved.
By the mid-1990s, the United States FSI companies successfully developed first by military technology (FPA) conversion and commercialization of new infrared camera (CCD) is a focal plane array structure of a cementitious imaging device, more advanced technical capabilities, spot temperature measurement is only targeted exposure of the image, and the information stored in the computer's PC card, that is, the completion of all operations, various parameters set to go back to modified interior with software and analyze the data, the final inspection report obtained directly, due to technical improvements and changes in the structure, replacing the complex mechanical scanning, instrument weight has less than 2 kg, use as a handheld video camera, can be easily operated with one hand.
Today, infrared thermal imaging system has been in power, fire control, chemical and medical, and other areas has been widely used. Infrared camera in the world economy is playing an important role.
2.3 thermal imager classification
Infrared spectrophotometry machine scanning General imaging systems and non-scan Imaging System. Light machine scanning imaging system uses the unit or plural (element number 8, 10, 16, 23, 48, 55, 60, 120, 180 or even more) photoconductive or photovoltaic infrared detectors, use detector is slow, mainly frame picture response time fast enough, multiple array probes can be made into high-speed real-time thermal imager. Non-scan imaging of thermal imager, such as the recent launch of array staring imaging of focal plane thermal imager is a new oneGeneration of thermal imaging device performance is much better than light machine scanning imager, gradually replacing light machine scanning imager trend. Its key technology is the detector from monolithic integrated circuit, the measured goal of the entire field of vision is focused on it, and the image clearer, easier to use, the instrument is compact, with auto-focus image freeze, continuous zoom, point temperature, such as temperature, moderate line voice comment images, and other functions, the instruments used PC card storage capacity up to 500 images.
Infrared TV is the infrared camera. Infrared TV through the Pyroelectric camera tube (PEV) accept the measured object's surface infrared radiation, and to target the distribution of heat radiation in the invisible thermal images into video, thus, Pyroelectric camera tube is infrared light key device TV, it is a real-time imaging, wide spectral Imaging (3 ~ 5 μ m and 8 ~ 14 μ m better frequency response) with a medium resolution of thermal imaging devices, mainly by the lens, target surface and the electron gun made up of three parts. Its technical features are to be logging target line of infrared radiation Imaging through the lens to the Pyroelectric camera tube, used at normal temperature hot TV detector and electron beam scanning and target surface imaging technology. Thermal imager of main parameters are:
2.3.1 working band; work in-band refers to thermal infrared imager in the infrared detector response wavelength region, usually 3 to 5 μ m or 8 ~ 12 μ m.
2.3.2 detector types; detector type refers to the use of an infrared device. Is the unit or plural (element number 8, 10, 16, 23, 48, 55, 60, 120, 180, etc.) photoconductive or photovoltaic infrared detector, which uses the element has lead sulfide (PbS), lead selenide (PnSe) and TE insb
(InSb), Mercury cadmium telluride (HgCdTe), tellurium, Tin, lead (PbSnTe),germanium doped (Ge: X) and Silicon-doped (Si: X), etc.
2.3.3 scan systems; General for our standard SECAM, PAL.
2.3.4 display; refers to the screen is black and white display or pseudo color display.
2.3.5 temperature measurement range; means for the determination of the minimum temperature and the maximum limit of the temperature range of values.
2.3.6 temperature measurement accuracy; infrared temperature of maximum and instrument range of percentages.
2.3.7 maximum working hours; infrared imaging system allows continuous working hours.
3. infrared temperature measurement
3.2 infrared thermometer working principle
Understanding infrared thermometer works, technical indicators, environmental conditions and the operation and maintenance of the user in the proper selection and use of infrared thermometer. Infrared thermometer by the optical system, photoelectric detectors, signal amplifiers and signal processing, display the output. Optical system brings together its vision of infrared radiation energy, field of view of the size of the thermometer of optical parts and location decisions. Infrared energy is focused in photoelectric detector and transformed into the corresponding signal. The signal amplifier and signal processing circuitry in accordance with the instrument's internal algorithms and target emissivity correction after changes to the measured temperature value of the target. In addition, you should also consider the target and the thermometer are environmental conditions such as temperature, climate, pollution and noise and other factors on the performance indicators of impact and correction methods.
All temperature higher than absolute zero objects are kept to the surrounding space issue infrared radiation energy. Objects of infrared radiation energy of the size and distribution by wavelength — and its surface temperature is very closely related. Therefore, the object itself radiation measurement of infrared energy, will be able to accurately measure the surface temperature, this is the infrared radiation Thermometry is based on an objective basis.
Law of blackbody radiation: blackbody is an idealization of the radiator, it absorbs all wavelengths of radiation energy, did not reflection and through energy, its surface emissivity is 1. It should be noted that, in nature and does not exist the real bold, but to find out what the and infrared radiation distribution, in theory you must select the appropriate model, this is the body cavity of Planck's radiation of quantum oscillator model to export the Planck's law of blackbody radiation, wavelength said of blackbody radiation spectra, this is all theory of infrared radiation, therefore calls the law of blackbody radiation.
Object emissivity effect on radiation Thermometry: nature of the actual object, not a blackbody. All the actual object of radiation wavelength than dependent radiation and temperature of a body, and form the object of material types, preparation method, thermal process, as well as surface and environmental conditions and other factors. Therefore, in order to make the blackbody radiation law applies to all actual objects, you must introduce a and material properties and surface condition of scaling factors, namely the emissivity. The coefficient indicates that the actual object in thermal radiation and how closely the blackbody radiation, its value is zero and less than 1 between the numeric value. According to the radiation law, as long as known material emissivity, know any objects of infrared radiation.
Main factors influencing emissivity yarn in: material type, surface roughness, physical and chemical structure and material thickness, etc.
When using infrared radiation thermometer to measure the target temperatures must first measure goals in the wavelength range of infrared radiation, and the thermometer calculated temperature of the measured object. Monochrome thermometer and band in proportion to the amount of radiation; two color Pyrometer with two wavelengths of radiation is proportional to volume ratio.
Infrared system: infrared thermometer by the optical system, photoelectric detectors, signal amplifiers and signal processing, display the output. Optical system brings together its vision of infrared radiation energy, field of view of the size of the thermometer of optical parts and its location. Infrared energy is focused in photoelectric detector and transformed into the corresponding signal. The signal amplifier and signal processing circuit, and in accordance with the instruments of the algorithm and target neiliao emissivity correction after changes to the measured temperature value of the target.
3.3 infrared thermometer performance
InfraredThermometer is fired by receiving target objects, reflection and transmission of energy to measure the surface temperature. Thermometer probe components within the acquisition of energy information to the microprocessor to process, and then converted to display the temperature readings. In laser aiming device models, laser aiming device only aiming to use.
Its performance instructions such as table 1.
Temperature range-32 ° c-400 ° c display resolution 0.1 ℃ (< 199.1 ° c)
Precision 23 ℃ ± 1% of the working temperature range 0-50 ℃
Repetitive 23 ℃ ± 1% to 30 ° c relative humidity 10-95%
Response time 500ms power 9V
Response spectra 7-18micron size 137 × 41 × 196mm
Maximum display Have weight 270g
Emissivity 0.95Preset waterproof under fire forces require special production
Table 1 performance infrared thermometer
In order to obtain an accurate temperature reading, thermometer and the distance between the test target must fit within the scope of the so-called "light point size" (spot size) is the thermometer measuring points of the area. Your distance goal spot size further. The right picture shows the distance and spot size ratios, or D:S. In laser aiming device typethermometer, laser point above the target Center, 12mm (0.47) distance of bias.
Measure distance and spot size
In measuring distances, should ensure that objective diameter equal to or greater than the point size of respondents. The image on the right labeled "objects", no. 1 (object 1) and the distance between the measuring instrument is, because the target ratio was slightly larger metering point size. The "object", no. 2, distances, because the target is less than the spot size instrumented, thermometer measurement with the background objects, which reduces the accuracy of the readings.
4. infrared thermometer right choice
Select infrared thermometer can be divided into three areas:
(1) performance indicators, such as temperature, spot size, working wavelength, measurement accuracy, window, display, and output, response time, protection, accessories, etc.;
(2) environmental and working conditions, such as temperature, window, display, and output, protection, accessories, etc.;
(3) other options, such as easy to use, maintenance and calibration of performance and price, but also on the thermometer of choice to produce certain effects.
As the technology and development, the infrared thermometer is the best design and development provides users with a variety of functional and versatile instrument, expanded choice. Other choices, such as easy to use, maintenance and calibration of performance and price. In the select thermometer model should first determine the measurement requirements, such as the measured target temperature, measured the target size, measuring distance, measured target materials, the target environment, response speed, accuracy, using portable or on-line, and so on; in an existing various types of thermometer contrast, elect to meet the requirements of the instrument model; in many to meet the above requirements model, select the performance, functionality, and price of best match.
4.1 determine temperature measuring range
Determine the temperature measuring range: measuring range is the thermometer one of the most important performance indicators. If Raytek (Raytek) product range is-50 ° c-+ 30 ° c, but this is not a type of infrared thermometer. Each type of thermometer has its own specific temperature range. Therefore, users of the measured temperature range should be considered accurate, comprehensive, neither too narrow nor too wide. According to the law of blackbody radiation spectrum of short wavelength radiation caused by temperature changes will exceed energy by emissivity errors are caused by changes of the radiation energy, therefore, when you try to use temperature short is good. In General, the more narrow temperature range, monitoring the temperature, the higher the resolution of the output signal, precision reliability, easy to solve. Wide measuring range, temperature measurement accuracy will decrease. For example, if the measured target temperature of 1000 degrees Celsius, first determine the on-line or portable, if it is portable. Meet the temperature of the model, such as 3iLR3, 3i2M, 3i1M. If accuracy is important, it is best to choose 2 m or 1M model, because if you choose to use the 3iLR-measurement range is wide, the high temperature measuring performance is less; if a user in addition to measuring 1000 degree Celsius target, but also take care of low-temperature objective, then had to select 3iLR3.
4.2 target size
Infrared thermometer in accordance with the principle can be divided into a monochrome thermometer and two color pyrometer (radiation colorimetric thermometer). For monochrome thermometer, temperature, measured target area should be filled with thermometer field of view. Recommended that the measured size of the target size more than 50% of the field as well. If the target size is less than the field of view, the background radiation energy will enter the thermometer of acoustic interference temperature readings are supported, resulting inerrors. Conversely, if the target field is larger than the thermometer, thermometer is not affected by the measure the area outside the influence of the background. For colorimetric thermometer, its temperature is composed of two independent of wavelength band radiation energy ratio. So when the measured goal is very small, not full field of view, the measurement channel on fumes, dust, barrier, there is the radiation energy attenuation, are incorrect measuring results have a significant impact. For small and is in motion or vibration of target, colorimetric thermometer is the best choice. This is because light diameter small, flexible, and can be bent, barrier and collapse of channel transmission light radiation energy.
For Raytek (Raytek) two-color pyrometer, temperature is composed of two independent of wavelength band radiationEnergy ratio. So when the measured goal is very small, no full-scene, measuring path on fumes, dust, blocking on radiation energy attenuation, will not affect the measurement results. Even energy attenuation up to 95% of cases, you will still be able to guarantee the required temperature measurement accuracy. For target small, and is in motion or vibration of goals; sometimes depending on venue motion, or may remove part of the target field, under these conditions, the use of two-color thermometer is the best choice. If the thermometer and the destination is not possible to directly target, measuring channel bending, narrow, blocked etc., two-color fiber optic thermometer is the best choice. This is due to its diameter is small, flexible, and can be bent, barrier and collapse of channel transmission light radiation energy, so you can measure difficult to access, conditions or toward the goal of the electromagnetic field.
4.3 determine distance coefficient (optical resolution)
Distance coefficient determined by D:S ratio, i.e. the thermometer probe to the target distance between D and the measured object diameter ratio. If the thermometer as environmental conditions must be installed away from the target, but also to measure small goals, you should select the high optical resolution of the thermometer. Optical resolution is higher, i.e. increase D:S ratio, thermometer, the higher the costs. Raytek IR thermometer D:S range from 2: 1 (low distance coefficient) to more than 300: 1 (high distance coefficient). If the thermometer off target, and the destination is low, you should select the high distance coefficient of the thermometer. For fixed focal length of the thermometer, the focus in the optical system for spot minimum position, near-and far from the spot will increase the focus location. There are two distance coefficient. Therefore, in order to be able to close and far away from the focus on accurate temperature measurement of distance, measured target size should be larger than the focus at the spot size, zoom thermometer has a minimum focus position, according to the target distance. Increasing the energy received D:S, reducing, if not increase the receive diameter, distance coefficient D:S difficult, this would increase the cost of equipment.
4.4 determine wavelength range
The target material and surface properties of emissivity determines the thermometer of Spectra corresponding wavelength for high reflectivity alloy material, with low or changing emissivity. In the high temperature area, the best measurement of metals is the near-infrared wavelengths, optional 0.8 ~ φ1.0 μ m. Other temperature can choose 1.6 2.2 m, μ μ μ m m and 3.9. Because some of the material in certain wavelengths is transparent to infrared energy will penetrate these materials, such materials should choose special wavelength. If the internal temperature measuring glass selection φ1.0 m, 2.2 μ μ μ m and 3.9 m (measured to very thick glass or through) wavelength; measuring glass surface temperature selection ¦µ5.0 μ m; low temperature measuring 8 to 14 in selection of μ m. If measurement polyethylene plastic film selection 3.43 μ m, polyester class selection of 4.3 m or 7.9 μ μ m, thickness exceeding 0.4mm of μ m 8-14. If the log fire in CO for narrowband 4.64 μ m, measuring NO2 flame of 4.47 μ m used.
4.5 determine response time
Response time means infrared thermometer on the measured temperature reaction speed, defined as reaching the final reading of 95% energy need time, and photoelectric detector and signal processing circuits and displays system time constant. Raytek (Raytek) new infrared thermometer up to 1ms response time. This is not as simple as contacting temperature measurement method is much faster. If the target of the campaign quickly or measurement of rapid heating of the target that you want to use quick response infrared thermometer, otherwise can not reach enough signal response, will reduce the measurement precision. However, not all applications require quick response infrared thermometer. For static or target thermal process exists when the thermal inertia, the thermometer of response time to relax. Thus, the infrared thermometer response time to select and test goals. Determine response time, depending on the target's movement speed and the speed of temperature change objectives. For static goals or objectives ginseng in thermal inertia, or existing control device speed limits, the thermometer of response time to relax.
4.6 signal processing functions
In view of the discrete process (such as a parts production) and continuous process is different, so called infrared thermometer has more signal processing functions (such as peak hold, Gu values, average) are available, such as measuring conveyor belt bottle, we maintain with peak, its temperature of output signals transmitted to the controller. Otherwise the thermometer readout bottle between low temperature value. If the peak keeps the set temperature is slightly longer than the response time interval between the bottle so that at least one bottle is always in a measurement.
4.7 environmental conditions to consider
Thermometer environment conditions on measurement results have great impact, should be considered and appropriate solution, otherwise it will affect the measuring accuracy even causes damage. When the ambient temperature is high, the presence of dust, smoke and steam conditions, the choice of manufacturers of protective sleeve, water cooling and air cooling system and air blowing machine and other attachments. These attachments can effectively address the environmental impact and to protect the thermometer for accurate temperature measurement,. In determining the attachment, the requirements for Standardization service as possible, to reduce installation costs. When noise, electromagnetic fields, vibration or difficult to access environmental conditions or other conditions, smoke, dust or other particles reduce measuring energy letter signals, fibre-color thermometer is the best choice. Colorimetric thermometer is the best choice. In noise, vibration, electromagnetic fields and difficult to access in environmental conditions or other conditions should select light colorimetric thermometer.
In sealed or dangerous materials (such as containers or vacuum tank), thermometer observing through the window. Materials must be of sufficient strength and energy through the thermometer working wavelength range. To determine whether it requires the operator through the window to observe, to select the appropriate installation position and window material, to avoid interaction. In low-temperature measurement applications, often using Ge or Si material as window, impermeable to visible light, the human eye cannot, through observation of the target window. If an operator needs through windowMouth goal should be used in both through infrared radiation through visible light optical materials, such as should be both through infrared radiation through visible light optical materials, such as ZnSe or BaF2, etc. as window material.
When the thermometer work environment exists of inflammable gas, you can use the intrinsic safety type infrared thermometer, resulting in a concentration of the flammable gas, environment, security measurement, and monitoring.
In environmental conditions and complex cases, you can select the measuring head and display separate systems for easy installation and configuration. To select the existing control device matching signal output form.
4.8 infrared radiation thermometer calibration
Infrared thermometer calibration must pass in order to enable it to properly display the temperature of the measured object. If the thermometer in the use of a temperature variance, then returned to the manufacturers or repair center calibration again.

【 Weak current College 】 touchscreen principle describes 】

With the use of computers as sources of information is increasing day by day, touch screen, with its easy-to-use, durable, reaction speed, space saving, etc., enables system designers increasingly feel the use of the touchscreen does have a considerable advantage. Touch screen appears in the Chinese market has been only a few short years, this new multimedia devices yet to come into contact with and understanding of many people, including some are planning to use the touch screen of the System Designer, you have the touch screen as optional equipment, from developed countries touch screen universal history and our multimedia information industry is at a stage, the idea also has a certain universality. In fact, the touch screen is a multimedia information or control of the device, it did give multimedia system with a new feature, is very attractive new multimedia interactive devices. Developed by system designers and our first to use touch-screen system designers have already clearly know that touch screen for various application areas of the computer is no longer the easy thing is essential equipment.   It greatly simplifies the use of computers, even those who know nothing about computers, also can come in handy, so that the computer presents a greater charm. Address public information market computer cannot resolve the problem. Touch screen is the main three categories: resistive technology touch screen, touch screen surface acoustic wave technology, capacitive touch screen technology. Each type of touch screen has its own advantages and disadvantages, to learn more about the touch screen for the occasion, the key is to understand each type of touch screen technology works and features. A, resistance technology touch screen resistive touch screen is a key section of the display surface resistance combined with very thin screen, this is one of the many layers of film, it with a layer of glass or rigid plastic plate as a grass-roots, surface has a layer oftransparent metal oxide (ITO Indium oxide, transparent conductive resistance) conductive layer, a layer of the roof surface hardening treatment, smooth and polished plastic layer, its inner surface is coated with a layer of ITO coating, among them there are many small (less than 1/1000 inch) transparent isolation points to two layers of conductive layer separates the insulation.   When the finger touch screen, two layers of conductive layer in touch point location will have a contact, the controller detects this contact and calculate the (X, Y) location, and then under simulated mouse operations. This is the resistance technology touch screen for the most basic principles. Resistive screen since entering the market, with stable quality, * quality and environmental adaptability to occupy the majority of the height of the market.   Especially in the industrial field, due to its environment and conditions of high demand, further demonstrates the uniqueness of resistive screen, so that its products in occupies similar touch product 90 per cent of the market, has become the mainstream products on the market. Its greatest features is not afraid of the greasy dirt, dust and water. G-Touch latest fourth generation resistance technology touch screen and other resistive screen products differ in: it to glass plate for grass-roots, causing higher transmittance, reflectance index is more applicable to the consumer. At the same time, even coating glass bottom of conductive layer to adsorption on the touch screen of electrostatic particle uninstall through the ground to ensure that the touch location more accurate, sensitive, completely remove excessive charged particle-induced drift phenomenon, positioning no, response is slow, making it longer (physical measurement of single points of continuous use of up to 15 years), and has a maintenance-free, anti-scratch degree has also been significantly improved.   It is an excellent quality and reasonable price. 1, four-wire resistivescreen characteristics: high resolution, high speed response.   Surface hardness processes to reduce the abrasion, scratches and chemical processing.   With a glossy and matte surface treatment. Once calibrated, the stability is high, and never drift. Four-wire resistive analog technology in two layers of transparent metal layers work in each of the layers are added a constant voltage: 5V vertical and one horizontal orientation.   A total of four cable.   2, 5-wire resistive screen characteristics: high resolution, high speed response.   Surface hardness, reduce abrasion, scratches and interview with chemical treatment.   The same point contact 3000 million are still available.   Conductive glass-substrate media. Once calibrated, the stability is high, and never drift.   Five-wire resistive analog technology to the two directions of voltage through the resistor networks added * in layers of metal layers, * both detection voltage and current methods of detecting measured touch point location, and the outer conductor layer only as ITO, a total of five cables.   2, surface acoustic wave technology touch screen surface acoustic wave technology is the use of sound waves in the body of surface transport, when the body touch the surface, preventing the transmission of sound waves, transducer detect this change reflected to the computer, and then make the mouse simulation.   Surface acoustic wave screen features: high definition, light transmission rate.   Highly durable, resistant to scratches of good.   Once correction not drift.   A responsive. Ideal for offices, authorities and the environment cleaner. Surface acoustic wave screen needs regular maintenance, because dust, greasy stain even drink liquid surface in screen, you are blocking the touchscreen surface of waveguide slot, so that the wave doesn't launch, or enable waveform changes controller does not recognize, thus affecting the normal use of the touch screen, users need strict attention to environmental health. Must always wipe the surface of the screen to keep the screen smooth, and periodically make a complete wipe. Third, the capacitor technology touch-screen used for current sensing in the body.   User touch screen, because the human body-field, users and touch-screen surface with a coupling capacitors, high-frequency current, capacitance is direct, so your finger from the conductor contact point sucked away a small electric current.   The current from the touchscreen of the four corners of the electrode, and through these four electrode electric current and the finger to the four corners of distance proportional to the controller through the four current accurate calculation of proportion, that the position of the touch point. Capacitive touch screen features: for most environmental pollutants have resistance.   Part of the human body become lines, bleachingMove in a more serious.   Does not work with gloves.   Need regular calibration. Does not apply to a metal cabinet. When outsiders inductance and magnetic induction, cause the failure of the touch screen.

【 Weak current College 】 advertisers how to purchase high-quality LED large screen 】

This years LED large screen demand soared, causing various size factory mushrooms grow, suddenly all say their own good, the bad and the ugly customer difficile, but most of them price-oriented. But as the saying goes, buyers than sellers, generally means the buyer how to go down, go to the astute requires sellers, but also difficult to smart too sellers, let the sellers account. The result is like a million of BMW didn't buy it bought 300 Jetta.
However, as a member of the integrity of the manufacturer, you should put the industry's important information prior to tell buyers for their choice not to pursue the information asymmetry.

LED full color large screen after several years of development, rough look seems to have a mature industry, as a matter of fact, whether domestic or foreign manufacturers, is still a long way to go, especially outdoor large screen, most of the products after two years of operation, it is difficult to maintain within the user's expectations.

Why is that?

Here first of all a big misunderstanding, most people think that the main materials LED screen, IC life has reached 10 000 hours, 365 days/year, 24 hours/day running, the service life of 11 years, most customers are concerned only with the renowned LED and IC. In fact, this thing is a necessary but not sufficient condition, because the red, green, blue three lamp of fair use, the display effect is just as important, different colors of light, to make it work in the best condition, for a good display will become more important. IC's reasonable control, also help to overcome the PCB wiring problems are not reasonable. Just like a car with a good engine and circuit control, not necessarily become a good car. This is a critical factor is this:

Because of the LED, IC is a semiconductor device, their conditions of use on the environment, preferably in the required room temperature of around 25 ° c, its the best working mechanism. But in fact a outdoor large screen are applied at different temperatures, summer may be in more than 60 ℃, winter may at-20 ° c below. When manufacturers product is 25¡æ to test conditions, the different product categories, fact tranche running condition of 60 ° c or-20 ° c, then LED, IC work efficiency and performance are not consistent, you may actually belong to a stall of becomes more stalls, brightness is inconsistent, the screen body naturally become flowers. This is because in different temperature conditions, red, green and blue light attenuation and decline of brightness are different, and in 25 ℃, the white balance is good, but at 60 ° c, the three colors of the LED brightness is decreased, and the attenuation values do not match, it will produce a screen brightness decrease and partial color, full of quality will decrease. And IC? IC temperature range is-40 ° c-85 ℃. As the outside temperature is too high, causing the body temperature rises, if the box at the temperature exceeds 85 ° c, IC will cause overheating and result in instability, or drift to difference between current or movie channel difference too large to cause corruption.

At the same time, power is also very important, because the power supply in different temperature conditions, the stability of its work, the output voltage and load capacities vary, because it assumes the role of logistics support, so it guarantees the ability to directly affect the quality of the screen.

Cabinet design for display is also very important, on the one hand, the role of circuit protection, on the other hand is safe effect, dustproof, waterproof effect. But more importantly ventilation heat circuit system design is good, with the power-on time and outside temperature, thermal drift of components will also increase, which causes the image quality deterioration.

These factors are interrelated and that will affect the display of quality and longevity. Customers in the selection screen, but also a comprehensive study, tomake the right judgement.

Effect of temperature on the large screen still further, assume that the customer purchased a 6 m wide and 10 m high (60 m2) with large screen, while the total area is not large, but the internal composition of the unit, the unit of temperature between the boxes are not necessarily proportional to the temperature inside the box will also be affected by the impact of air convection temperature not consistent, causes the cell box or cell body temperature, brings the productivity of semiconductor devices, which reflected the glow brightness LED lamp, look for "flower" screen. Don't underestimate the outdoor temperature, if we think of summer in the car can be cooked eggs examples can be imagined. Moreover, led display under the summer sun is still shining display. (Stronger light than sunlight is valid), the glow will generate heat, these are influence factors.

Cold and hot temperature the fight not only vulnerable delicate led, IC and semiconductor devices, including strong ABS, face masks, iron box, connection parts, various types of welding points, mask in sunlight hypothermic scraping under and freezing rain after the moisture of multiple macroclimate, produce some deformation Alice angle up to 2-3mm, ultraviolet irradiation also makes the face mask plate color changes, so that in the year under various climate change, the audience can see mask plate itself will change color, a pattern plate, deformation will stop over point led lighting produces light dark areas deformation also affects the PCB welding point bending, causing the precarious, the virtual welding allows light when the LED is off. And because air moisture and oxidation causes reduced oxidation interface connectors, plus minor vibration and deformation, name:parts of Micron's coating without forming tight contact, lead to signal or power outage, large screen failure.

Deformation and mechanical fatigue also affect rail tank and outer frame, resulting in the screen body rugged, modular and iron box cannot bear the consequences of leakage and other parts.

Therefore, to choose a good screen, the first line must choose a good light, durable and strong adaptability, and other materials and technology assessment should not be taken lightly, is like the automobile, a few personal garage, or you can pick one automobile, tens of thousands of people of a factory is in the Assembly of a motor vehicle, the car number and travelling kmProtection coefficient should be quite different. Outdoor screen of waterproof resistance to deformation, manufacturing processes and key accessories, missing mile, the difference of a thousand miles.

In addition to consider major LED and IC components of quality, and sellers of prior communication are also very important. It not only directly affects the quality of the entire project, the success or failure and often to let user input in a more rational distribution of resources, avoiding unnecessary wastage and loss and the risk, even more significant benefits.

Manufacturers should be offered to users on actual demand and operability, etc. provide simulation programmes or better recommendation programme to help the customer reasonable analysis, planning, making the most cost-effective solution, users can become a trusted partner. Communication matters generally include the following:

1. clear your own needs, investment budget and desired best results;

2. detailed indications on the project requirements and to future development plans, and requirements for the seller to provide the best possible implementation of the programme, or even projects can extend functionality and development budget, plans to avoid project does not fit the needs of the future development and cause unnecessary waste of resources;

3. provide or require manufacturers to project setup and application environment to analyze data on expandable event prediction and prevention, the solutions as well as on the entire project plan to make a comprehensive assessment;

4 different LED production process, Assembly process, installation screen technology experience, will directly affect the whole project duration, cost, security, performance, display the results and quality, service life and maintenance costs, and therefore must from manufacturers or understand, compare products and projects in all aspects of performance and features, select the most suitable for their own needs;

5. understanding the manufacturers of strength, integrity, service and quality, these are projects to good and long-term cooperation and guarantee.

Plain to consumption, easy to use, and to wish each need big-screen customer, you can buy a satisfactory products, also wishes for large screen display in a user's request, to keep the bad as u, achieve a higher quality level.

Weak current College】 【monitor partial color fault handling】.

Monitor partial color is a common fault, repairing often pay attention to not cause false positives. In General, the exclusion of such failures can be divided into four steps.
The first step, first check the monitor color is in the high brightness or luminance low partial color. If the brightness high partial color, should adjust their color-balance potentiometer accordingly; if the brightness is low partial color, adjust the corresponding primary color dark balance potentiometer. In General, if there was a slight change circuit parameters, as a result of these adjustments may eliminate partial color faults. But adjusted before the adjustment potentiometer on the horniness, if not function through adjustments or role is very small, it should be restored to its original location, to ensure that the next overhaul of quality.
The second step, replace the corresponding depending on tube. If you are using a multimeter untestable corresponding partial color depending on tube is damaged or not, it is only through replacement tube test. Typically the change depending on tube argument should be placed with the original vision, pipe parameter, if the original depending on tube do have problems, it cannot be excluded after fault; if parameter slightly, by fine-tuning the corresponding light balancing effect can be achieved satisfactory potentiometer; if fine tuning is not troubleshooting, you should set the potentiometer reinstated.
The third step, check the three depending on tube collector load resistance, its resistance is changed, if normal then check the bright, dark balance does change, potentiometer resistance if changes should be replaced. Typically, replaced by fine-tuning the partial color faults cannot be excluded.
The fourth step, if the third step is still not clear the fault, it is possible to change the picture tube parameters, you should use the following procedure to adjust to the best effect:
(1) to enable monitor power more than 10 minutes;
(2) will light up the middle balance potentiometers placed;
(3) the accelerator potentiometer pare, chroma, brightness, contrast to the minimum;
(4) the maintenance of the switch to a horizontal light line location maintenance status;
(5) the accelerator potentiometer slowly clockwise rotation to a base-line Pico appears on the screen;
(6) adjust the other two primary colors in dark balance potentiometer to make the screen lit line become white;
(7) will repair switch back to normal position and adjust light balance potentiometer, observation of high brightness, white balance.
Repeated the above (4) to (7) steps, until the white balance is satisfied.

【 Weak current College 】 switch main parameters 】

(1) rated voltage means the switch in the normal working time allowed by the proprietor. If adds in the switch both sides voltage greater than this value, it will create two contact points between the brand impact of breakdown.

(2) rated current when the switch is switched on, the maximum allowed through security operating current. If the current exceeds this value, the switch contacts will was too big to burn.

(3) the insulation resistance is the switch of conductor section (metal component) and the insulation resistance of the parts. Insulation resistance value should be 1 O O M Ω or more.

(4) contact resistance is the switch in the on-State, each pair of contacts between the resistance value. General requirements contact resistance value at 0.1-0.5 Ω following, this value as small as possible.

(5) the voltage is switched between the conductor and can bear minimum voltage values.

(6) life is the switch in the normal working conditions can operate. General requirements in about 5000-35000

Weak current College】 【anti-static shoes, conductive shoes of safety technology requirements】.

<br> <br> National Bureau of 1984-05-14 publication 1985-01-01 implementation <br> <br> This standard applies to flammable, explosive and other places, the workers to eliminate static electricity human body wear antistatic <br .> <br> Rubber-soled shoes and conductive rubber-soled shoes. <br> <br> This standard is the reference of ISO2251 and ISO2024 <br> <br> 1 dress Forum <br> <br> 1.1 anti-static rubber .soled shoes <br> <br> Anti-static rubber soled shoes mainly used to prevent the human body with static electricity may cause burning, explosion of sites (for example, rubber, chemical, printing, medical, electronic and other industries in some places .). At the same time, it can avoid the 250V following accidental electrical equipment on the human body due to electric shock and fire. <br> <br> 1.2 conductive plastic shoes <br> <br> Conductive rubber soled shoes mainly used to .prevent the human body with static electricity, fire, explosion of sites (for example, initiating trades certain premises). But it only applies to workers not to be subjected to electric shocks. <br> <br> 1.3 for maintenance of power equipment or .handling of high voltage electric equipment with an electric shock hazard, prohibit wear anti-static rubber-soled shoes, conductive rubber-soled shoes. <br> <br> 2 performance indicators <br> <br> 2.1 electrical performance indicators <br> .<br> 2.1.1 anti-static rubber soled shoes <br> <br> In shoe wear, 84 by GB4386-the anti-static rubber-soled shoes, conductive rubber soled shoes resistance measurement method for the measurement. Anti-static rubber .soled shoes sole of resistance must be 0.5 × 10 ^ 5 Ω to 1.0 × 10 ^ 8 Ω. <br> <br> 2.1.2 conductive rubber soled shoes <br> <br> In shoe wear, press GB4386-84. Conductive .rubber soled shoes sole resistance value must be not greater than 1.5 × 10 ^ 5 Ω. <br> <br> 2.2 other performance indicators <br> <br> 2.2.1 anti-static rubber-soled shoes, conductive rubber soled shoes of .different performance requirements, must comply with the appropriate footwear of national standards and technical requirements. <br> <br> 2.2.2 for anti-static rubber-soled shoes, conductive rubber soled shoes by structure design and choice of materials used, the account .must be taken to make the shoes at the bottom of resistance to abrasion and changes under the influence of pollution. <br> <br> 2.2.3 on has the special request the anti-static rubber-soled shoes, conductive rubber soled shoes ( .for example, need to have acid, alkali, oil, etc) it should also be consistent with the appropriate technical standards. <br> <br> 3 wear requirements <br> <br> To ensure the Elimination of human 3.1 electrostatic effect, .wear anti-static rubber-soled shoes, the resistance of the ground shall be not greater than 1.0 × 10 ^ 8 Ω; wear shoes with conductive adhesive, the resistance of the ground shall be not greater than 1.5 × 10 ^ 5 Ω. < .br> <br> 3.2 shoe wear, anti-static rubber-soled shoes, conductive rubber soled shoes at the bottom of the insulation shall be stained with impurities. <br> <br> 3.3 shoe wear, avoid while wearing insulation strong or hair .thick socks, and insulating insole, etc. <br> <br> 4 soles of electrical performance test <br> <br> Anti-static rubber-soled shoes, conductive rubber soled shoes sole of resistance should be GB4386-84 the methods, .procedures for the measurement. <br> <br> 5 quality supervision <br> <br> 5.1 State authorized Inspection Unit to produce anti-static rubber-soled shoes, conductive rubber soled shoes of enterprise technologies, process equipment and other items for review .. The company targets to meet the requirement, and officially received the product inspection certificate, to production, sales, anti-static rubber-soled shoes, conductive rubber-soled shoes. <br> <br> 5.2 anti-static rubber-soled shoes ., conductive rubber soled shoes factory, the factory must be on each shoe soles of electrical properties, meet the standard requirements, shoes factory. Eligible products must have a certificate. In each pair of shoes, should be accompanied by a simple statement, a description .of product performance, use the scope, conditions and delivery time. <br> <br> 5.3 State authorized Inspection Unit has the right to production of anti-static rubber-soled shoes, conductive rubber-soled shoes for regular or periodic inspection by sampling .. In accordance with the standard production, product quality is poor, the inspection organization shall have the right to make a warning or suspension product certification. <br> <br> 6 flags <br> <br> 6.1 anti-static rubber soled shoes .<br> <br> In the shoes of the appropriate sites, to have the obvious signs at the same time to help in the shoe, print the words "anti-static". <br> <br> 6.2 conductive plastic shoes <br .> <br> In the shoes of the appropriate sites, to have the obvious signs at the same time to help in the shoe, print the words "conductive". <br> <br> <br> <br> <br>.

Friday, March 18, 2011

College】 【weak cold storage refrigeration equipment in use in small】.

<br> small army reporter in this article we will explore the refrigeration equipment in cold storage, especially in small cold storage and refrigeration equipment in the use of mini-cold storage. .<BR> Refrigeration equipment is the heart of a small refrigerator, a very important effect of a small refrigerator to run the most critical condition is good or bad refrigeration equipment. .Small refrigerator refrigerator refrigeration equipment is the main body, which there are many, divided by ammonia refrigerant system cooling equipment and cooling equipment are two mechanisms of fluoride. .Some mechanism for cooling equipment is the variety of fluorine refrigerant generic models, advanced equipment and more use of fluoride mechanisms of cold on the environmental impact of refrigerant R22 and other new refrigerants. .Fluoride system cooling equipment generally small size, low noise, safe, reliable, high degree of automation for a wide range, suitable for rural small-scale cold storage refrigeration equipment. .The refrigerator with a small refrigerator condensers and other refrigeration equipment and often referred to together refrigeration units, water-cooled chiller units and air units are divided. .Small refrigerator in the preferred form of air-cooled unit, it has a simple, compact, easy to install, easy to operate, the advantages of fewer ancillary equipment, refrigeration equipment that is easier to see. .<BR> Refrigeration unit refrigeration equipment refrigerator is the heart of the common compression chillers with open, semi closed and fully closed the points. .Fully enclosed small compressor, low noise, low power consumption and high efficiency. .It is a small model of choice for refrigeration equipment cold storage, fully enclosed by the composition of the compressor-based air cooled unit, can be made as split air-conditioning, as in the form of equipment hanging on the wall. .<BR> Better on the market today closed refrigeration compressor to the developed countries of the refrigeration equipment imported or joint venture more reliable product quality, but the price is high compared to more than 50% of domestic affairs fund, small towns are more suitable for cold storage refrigeration .equipment. .<BR>.

Weak current College】 【power inverter basic common sense】.

<br> <br> In-car power inverter-related FAQ <br> First, power inverter common sense 1. What is a power inverter? <br> Power Inverter (on-board power supply) is a way to convert DC12V DC .and AC power supply AC220V, same for General Electric, is a convenient power converters. <br> 2. power inverter in domestic and foreign markets? <br> Power inverter in foreign markets has been generally welcomed. Abroad because of the high prevalence of .cars, out of the city in no occasion to work or travel you can connect with inverter driven automotive batteries, electrical appliances and power tools. <br> 3. why in domestic marketing this product? <br> China entered the WTO, domestic market .surging more and more, therefore, power inverter for use in automotive mobile DC variable AC power converter, will give you the convenience of life, and car owners must-have items. <br> 4. Power Inverter can only use in-vehicle system .? <br> Power Inverter not only applies to in-vehicle system, as long as there are DC12V power supply, can use the power inverter converts the DC12V AC220V AC, to your life easier. <br> 5. Power Inverter with high and .low alarm and shutdown function is the embodiment of? <br> Power Inverter with high and low voltage alarm and shutdown when the red LED light, and beep. <br> 6. Power Inverter on battery protection function? <br> Power inverter in .battery with battery, the battery voltage is reduced to 10V, power inverter automatically shut down in order to guarantee the car start correctly, the battery will not be damaged. <br> 7. Power Inverter how battery protection function? <br> Power inverter .is set by internal electronic circuit, automatic battery protection function. <br> 8. Power Inverter fault most prone to? how do I troubleshoot? <br> Power inverter, if there is downtime and alarming phenomenon, to check the following items: < .br> 1) driven by electrical power is more than the inverter power rating. <br> 2) power inverter and batteries and electric appliances is a good connection. <br> 3) using the process down, is the temperature alarm, stop for .a period of time may continue to use. <br> 9. how to use the power inverter? what considerations exist? <br> Use the power inverter power supply system to battery voltage value, and read the instruction carefully before use. <br .> Second, power inverter manufacturing process <br> 1. Power Inverter manufacturing in SMT technology, what is SMT process? <br> "SMT" called "automatic programming Mounter," and "patch" is in fact a resistor of a package. .Its high precision and small size, high degree of automatic processing, component welding good reliability, power inverter is achieved by SMT processing production of the product. <br> 2. What is a single chip? <br> All through the CPU microprocessors to .achieve a high and low voltage alarm, protection, and other parameters and function of the power inverter models called MCU type. <br> 3. What is a simulation of the machine? <br> Through the separation of components to achieve power inverter with .various parameters of the function model, called the Simulator. <br> 4. Power Inverter which performance characteristics? <br> Power inverter converts the DC12V 220V. It has the following features: <br> 1) input high voltage, low-voltage .alarm and protection. <br> 2) overload protection. <br> 3) instant impact 2 times the rated power. <br> 4) overload, short circuit protection. <br> 5. Power Inverter works? <br> By CPU .microprocessors implement PWM pulse, through high-frequency transformer 12V low voltage will become about DC voltage 300V. And then by CPU output 50 Hz AC drive signal, drive power switch. Through the power tubes of conduction conversion and achieve output RMS square wave forms of .average 220V AC voltage. <br> 6. power supply voltage of the inverter output is stable? <br> Power inverter output voltage feedback confirmation by itself makes voltage stability. Without load and rated voltage value is less than 10V. <br> 7 .. how to determine its stability in value to users is secure? <br> Power inverter to take full account of the external environment, in the event of overload or short circuit, power inverter protective shut-down automatically. <br> 8. power .inverter output frequency mean? what is its output frequency? <br> Power inverter output frequency refers to the periodic exchange of square wave output. Its frequency is 50 Hz. National standard is 50 Hz power supply. In General, the cycle to 20MS, .F 1 / T 50HZ. <br> 9. What is the continuous output power? <br> Continuous power means the power inverter in normal circumstances, can the power of continuous work. <br> 10. What is the peak output power? .<br> Peak power is the power inverter in Splash Instant affordable power, usually refers to the load on the motor type. When a startup because the start-up current is large and the formation of an instant-start power, known as peak power .output. <br> 11. Power Inverter of continuous output power and peak output power? <br> Sustained power and peak power, because of its expression. <br> Continuous load current value × 220 (AC voltage) <br> Start the .load 2 × power values <br> In General, electrical or electronic tools start load determines whether your power converter has the ability to drive it. <br> 12. What is inductive load? <br> Typically, a general load with inductive load .parameters, that is, consistent with the current advance voltage characteristics of load, become the inductive load. <br> 13. What is capacitive load? <br> General load with the load capacitor characteristics parameters, that is in line with voltage exceeding current .characteristics of the load, called capacitive load. <br> 14. with inductive load and capacitive load? <br> Load characteristics. First select a load must conform to the power inverter power rating. As long as they meet the power inverter use conditions .with capacitive and inductive load effect is the same. <br> 15. power inverter output waveform and output voltage 220V, what are the differences between them? <br> Power inverter output analog sine wave, but the city is a true sine wave. .<br> 16. power inverter output waveform is output 220V voltage values are the differences? <br> Power inverter output 220V voltage value and the value of the voltage. <br> 17. power inverter is only applicable to 11-15V input voltage .DC? <br> Power Inverter can only apply to 11V-15V input voltage DC. <br> 18. beyond or below the output values can apply and work? <br> Below the input values, power inverter produces low-voltage alarm, .please note that electricity load. When the input voltage is low, the power inverter automatically protected. Higher than the input value, the power inverter automatically protected when the input voltage is far greater than the damage the power inverter power components. <br> 19 .. how to understand the power inverter conversion efficiency? <br> Power inverter converts efficiency generally refers to output valid power and input of the ratio of total power. Can understand conversion efficiency higher the better. <br> 20. Power Inverter load current value .? <br> No-load current means power inverter without any electricity, its consumption. <br> 21. Power Inverter of the cooling fan is mainly played? <br> Power Inverter heat from the cooling fan main. Using the side panel fan .ventilation forming air convection, power inverter power components work in a safe temperature environment. <br> 3, power inverter using security <br> 1. the present power inverter which model? <br> Currently on the market there are the power inverter 150W ., 400W, 600W, 1000W, 1500W, 2000W, 3000W, 225W portable hand-held, 400W. <br> 2. how to choose the appropriate model? <br> Choose the power inverter can you live and work in use to select. .Such as: 150W power inverter can use a 29 inch TV set and a VCD. <br> 400W power inverter can use general electric tools. <br> 1000 Watt power inverter can be used to drive a small microwave ovens. <br> 3 .. Power Inverter uses the input power is available only from the vehicle stationary or running? <br> You can use the input power is derived from automobile running status, or rest. <br> 4. If the vehicle is stationary State, can I .use a power inverter to work? where the input power source available? <br> Car at rest, you can use a power inverter, driven appliances may be lower than the 150W directly from the cigarette lighter socket gets output power, higher than when you .want to use a dedicated 150W clips cable connects the car battery for power supply. <br> 5. how to determine the power inverter gets power you can use the time? <br> And power inverter matching batteries when generally the ampere (AH) .for electricity metering unit, such as the battery 80AH divided by the electrical power multiplied by 10 to the power inverter with electrical appliances in use. <br> For example, a television set 100 Watt <br> 80-100 Watt when ÷ × 10 .8 hours <br> 6. Power Inverter work surface temperature? is there a security risk? <br> Power Inverter at maximum power output, not higher than 70 ° c, does not have security implications. <br> 7. Power Inverter protective .device? <br> 1) temperature protection. Surface temperature above 70 ° c, automatic turn-off. <br> 2) high voltage protection. Input voltage 16V ± 0.5V <br> 3) low-voltage alarm. Input voltage 10.5 .V ± 0.5V <br> 4) low voltage protection. Input voltage 10V ¡ .à 0.5V <br>.