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Application of LED driving

Battery driven single LED, wide application of miner’s lamp, flashlight, emergency lights and other products. can find 20-400mA fixed current in led market. we will talk about LED backlight LCD driver ic. It is a very large size and according to the backlight LCD linear LED representation of the driver IC, linear IC power design as well as the feedback sampling automatically adapt to LED; VF value; 4 channel of LED constant current output, consistent with the R/G/B color combinations of 3:6:1 with high color rendering requirements. Can be applied to the high requirements of back light,The current market sales in good condition, more and more manufacturers adopt. The utility model has the advantages of simple design, simple circuit, convenient application, gray performance is currently the world’s one of the best (level 65536). The drawback is, these IC need large power supply and high cost for design.
The cost of power supply part is higher than LED driving part.
at present ,application of wash wall lamp, stage lighting, the screen lighting(seek higher requirements light ). Gray is very important performance factor for design in LED IC in the future. Single channel high power LED constant current DD311 driver ,it is the constant current driver for a single channel LED output, built-in current mirror and the current switch component, is designed for driving large power LED chip. it can drive up to 1 A input current (sink current), and through the adjustment of the reference input current (IREF) to arbitrarily set the size of the output current. The output current value is about 100 times of IREF, IREF by adjusting the external resistor or bias (bias) voltage to set the fine-tuning or make the bias voltage can be corrected LED light. it has achieved overall brightness at the same time adjustment. The output of the led chip can withstand voltage up to 36V, connecting application support multiple high power LED series. Built in output enable terminal (Enable), can easily achieve high gray scale application of high power LED. Features: the maximum output current: 1A (by the reference input current IREF settings) minimum output voltage requirements: 1V (when Iout = 1A) maximum output under voltage: 36V (output channel leakage current of less than 0.1uA).

Control of LED lamp with FPAG system or C/OS2 II operating system

FPGA
Landscape lamp in the traditional sense with a control box, single-chip, ARM control, color changes, only seven kinds of light color change mode,There is a single way on the led changes, and has limit for hardware control system speed.microcontroller family of embedded controllers PWM (PulseWidthModulation) generally only 3 to 6-chanle, if the need to expand only using software PWM. Function, can not meet the requirement of high speed transmission of data.control of LED lamp with FPAG system or C/OS2 II operating system Especially when the LED lamp for a long time to fade in and fade out, will cause jump process obvious in entire process of fade in and fade out. In order to let the eye looks no jumping, to achieve the gentle fade in and fade out effect, must rely on a powerful processor to complete the requirements. The system uses Nios II soft core embedded into the FPGA based SOPC(SystemonProgrammableChip) method, Nios II soft core processor on a PWM independent control of R (red), G (green), B (blue) light gray to control landscape lamp, landscape lamp control implementation of LED full-color display.The communication mechanism between multi processes in the business field, has obtained the successful should Using [526]. The use of programmable SOPC technology and C/OS2 II operating system is a good choice for the design of control system of LED landscape lamp.
system function description
The system is composed of a display unit, a display drive unit, control unit, data communication unit,Figure 1 system structure diagram
Using Nios II soft core with FPGA, by C/OS2 with real-time operating system by using the signal way by changing the PWM (pulse width modulation) duty cycle to achieve control the [7] scene playing on LED lamp group, showed the least 256 colors, with static, gradient, light gradually, gradually dark, flashing 5 types of change
Type and effect of full-color dynamic changes. Data communication unit by CF (CompactFlash) card, the lamp control data file of PC send out to control system. Control unit put the transmits light control data of PC into memory, to fetch and analysis data from the memory,the analysis and processing of finished lamp control data sent to the LED lamp driving unit, display unit control is realized by multiplex channel PWMA variety of change scenarios of LED lamp. The display drive unit is a custom Full color lamp control IP core, each IP control of a lamp through PWM. lamp control data show a scene change effect through the PWM port. Display the core device unit for three color LED tube, color with red, green, blue, produce various other different colors.

LED of Audi

According to the design of Audi LED headlights tears eyebrow lights, it is at the side of ordinary automobile (especially the left side) to install at least one side led lamp for road lighting side, The edge-lit lighting fixtures have a wide range of lit and low cost, using the installation of car sidelight lamp will greatly reduce night will be cars, overtaking traffic accidents .

To prepare A long 30 / 60CM, two with a line (30CM length of only one cable), which could be a group of three pcs led. Recommend a car to buy two! !

Color of lighting: white, blue, red, green

Uses; Universal tears LED Light (all models of car can be installed)

Material: 335 side-emitting, each lamp reaches more than 1000MCD

Length: 30CM / 60CM

Width: 0.6CM high 0.2CM (Universal Ultra Slim, specializing in tears Design)

Background(pcb color): black
First with 12V battery power to test tears led lamps, no problem and then start the installation,
the correct way is to remove the lamp strip after careful paste from the package inside the inner edge in the headlight, direct fixed! The power directly in parallel with the width lamp (lamp power line) can be, no direct (through the fuse) to connect the battery power supply!!!
Features: side-emitting light bar (also called tears), either brightness or effects can to replacing the old front SMD light bar of illuminated; this light bar can be arbitrarily cut (3 LED lights a group of cut),can mounted in any position。 Now there are many riders install door rail, light eyebrows or relatively narrow place, this section can choose light bar (regardless of length, width, thickness are the best), easy to install (the back of a double-sided plastic)!

1. Surface sealant

2. waterproof rating of IP68, suitable for indoor and outdoor use

3.DC12V voltage

4.The rugged, high shock resistance

5. The low-power, high-brightness

6. No radiation

7. The flexible, compact size, easy to install

8. Life: 10,0000 hours
9. Can withstand temperature: -20 ℃ to 50 ℃, operating temperature: 5 ℃ to 50 ℃

How to choose high quality components for power supply

As to improve LED performance, the power supply will also become a substantial part of the capability of the LED lamp. So to choose high quality components for power supply is an import thigh. Now we will talk about this.
PCB:
full use of first-class quality fiberglass board, non-cardboard, glass and other half-second material.
Component layout alignment:
The PCB layout and quality components is import and reasonable reason that related to design of product reliability and quality; the same material, different on PCB board layout, the final effect of the product is not the same; products with reasonable structure, in the simulation of transport and drop test, have an excellent performance when the anti interference test on the job; in the design high (AC alternating current)and low voltage complete isolation, safety distance is greater than the international standard 6mm, more to enhance the safety of the product.
Capacitors:
Capacitance using temperature -40ºC-105ºC, long life, international companies producing original brand products, mainly ruby, Black Edition, TOCON, YALECON other brands.
ledlightmake company integrates scientific research, production and sales, the company set up under the development department, production department, quality inspection department, various departments to strictly layers and responsible attitude, make the company’s products occupy a space for one person in the fierce competition in the market; rely on strong product quality to win led Markey and old customers the consistent high praise!

Test of constant current for led strip

Different switching power supply parameters are not the same, but most of the constant voltage of the switching power supply has a power matching function (with bleeder resistors), will be based on your load to adjust the current, which is in his case to ensure that the voltage supply on the move, power is automatically adjusted according to the load current to output the required power, so you can go to test and check that the power supply .to validate if the power supply is appropriate for led strip. And verification method is also very simple. Common chips of led strip are the following: 3020,3528,5050 and so on, the common 3528 lamp beads per meter 30 beads, 60 beads, 90 beads, 120 beads; 5050 lamp beads 30 beads, 60 beads, 72 beads;
but the most common way is 3 serial links and, according to the circuit connection mode can be calculated easily out of current, such as 3528 of the 60 bead light strip, is also 3 string and 20 parallel, according to each 20MA current, this current is 20 * 20=400MA, at this point, you can use the multimeter to measure current, see whether can meet the requirements, if conditions permit, you can the stability coefficient test power supply current, drive more stable is also more suitable for the LED lamp strip (because LED lamp beads are demanding constant current when LED lamp just work)!

How to choose LED Power Supply

The classification and choice of power supply LED
There are many kinds of classification methods of power supply:
According to the different output divided into constant voltage, constant current;
According to the characteristics of the input divided into general series, and high power factor series;
According to different purposes is divided into waterproof series, and is not waterproof series; According to the circuit structure is divided into different series of isolated, and not isolated series;
According to the control mode Divided into control mode adjustable light series, and adjustable light series.
LED has numerous advantages,in that case, environmental protection, long service life, photoelectric conversion efficiency, The LED life in the 10 Million hours Above But in the actual application process, Because of the design of driving power supply and driving mode selection is improper, or with LED Light does not match, draw the LED to damage or decay, Reduced LED The reliability of the lamp. Due to Different LED Manufacturers and LED specifications,output Current and Voltage also are different Now with white light LED for Cases,
In accordance The variation rules of the current and voltage. In general application of forward voltage 3.0-3.6V About, The typical value of voltage 3.3V Current 20mA,
When forward voltage more than 3.6V After The forward voltage is very small increase , LED The positive power Flow may have doubled up, draw the LED body temperature rise too fast
To accelerate LED Optical attenuation and Make LED Life shortening. Even be likely to burn LED.
According to the variation characteristics of LED Voltage, current。Put forward strict requirements on the design of driving power supply。

Share some experience that the LED lamp strip driving power

Now, share some experience that the LED lamp strip driving power
The intelligent LED lamp control is one of the advantages, and the power supply is the key of intelligent control.Intelligent control in LED street and LED tunnel lamp lighting application conditions most mature and the most obvious effect, intelligent control can control in different time, to realize stepless adjustment of lamp power according to the road traffic density, can meet the application requirements, and realize the enormous energy-saving effect, saves a large amount of funds for highway administrative unit. The application in the tunnel lighting can not only saving energy, can also according to the brightness of the situation outside the tunnel automatic adjustment of the tunnel entrance brightness, for the driver to provide a visual transition stage, in order to ensure driving safety.

1, giving up four or more outputs, develop single or two outputs, high current and large current to abandon the development of a small current.The more complex of outputs, the cost solve is very high current interference between the different way, if not solve high failure rate. Further more the total output current is greater, and the current is mainly due to the heat, the voltage itself does not lead directly to heat, heat and electric current is proportional to the square,, that current is increased 2 times than the original , then, the amount of heat will increase 4 times than the original, the original current is increased to 3 times, heat will increase to 9 times than the original. In summary, single or two-output LED light strip power failure rate will be much lower.
2, cooling and protection are the main external factor of a power failure.Not only the power supply may have a heat, lamps will be heat, How reasonable to heat dissipated is a matter of lighting design engineer must consider , must prevent the formation of heat, heat island effect, influence power life. Using separate power program is a good choice.
3, to give up power, super power, select a higher stability of small power supply.Because of the greater the power, the more heat generating by components,, which is also more compact components, is not conducive to heat dissipation, and the temperature is the culprit of a power failure. Furthermore, relatively small power development is more mature, stable and cost has advantages.
In fact, many large power supply are not tested over time and practice, are hastily implemented projects are experimental products, so that the failure of endless. Compared with small power supply for early development, technical solutions are more mature.

The power supply technology of LED

The continuous development of the LED lamp strip package technology and cooling technology in recent years, the stability of the LED lamp strip has reached a good level, the occurrence of light attenuation and color drift is mainly some copycat product manufacturers, the main reason is the unreasonable design of heat dissipation. Relatively speaking, LED lamp strip driving power supply problem is much more serious, it is the leading cause of death or flashing lamp main reason, that is to say, LED lamp driving power supply has become a short board of the LED lamp strip quality, according to the theory of barrel, life of LED lamp strip driving power supply is the life of the LED lamp strip.usually failure is a lamp – high pressure sodium,, high pressure sodium lamp, high pressure sodium lamp provisions of national standard warranty period of one year, the street lamp management unit will store a certain amount of sodium lamp, high pressure sodium lamp has mature national standards, the main parameters of its main parts size and power are unified and having interchangeability.current major fault of LED light bar in the power supply, so the main problem is to solve the power supply. But because of the standard is still a lack of LED power supply, power supply their own market, for example there are have a single road, the size is different, it is difficult to replace. With the advent of the market super power COB LED resource lights, LED tunnel lights, L LED drive power failure-prone, and the LED lamp with built-in driving design of power supply, often caused LED lamp power supply maintenance is difficulties, the lack of some manufacturers of after-sales maintenance services, so the owners complained, the influence of LED industry reputation.

IR LED for maintenance detection equipment(1)

Infrared thermal imaging is the industry an increasingly detection technology, general factory inspection application, main To improve the equipment operation reliability, industrial safety and energy saving for the purpose of. Factory equipment composed of electrical and mechanical, and with the application of electrical equipment detection is most to use. Also include rotation, detection of mechanical transmission device, furnace wall And the pipeline fire and heat insulation layer (insulating / cold) state detection.
Application of electrical equipment detection The low-grade damage to equipment harm and stop production, high -grade damage while in the occurrence of electrical fire. At the beginning of the different electrical equipment with electrical equipment detection of IR LED.

Detection work:
Including design, manufacture, installation and operation and maintenance work improperly will cause overheating problems electrical equipment; electric equipment Especially. the bad performance of conductivity, insulation, will bring abnormality detectable. The common causes of overheating
1, the contact resistance is too high: screw loosening or slide fastener, imbedded, oxidation, poor contact or contact area of less than the original to draw resistance is too high.

2, leakage or discharge: due to the equipment insulation is bad, such as along the surface pollution, humidity is too high, the insulation Degradation, lack of insulation from the many other factors, or over voltage.

3, overload: due to incorrect design planning, protection device of arrhythmia, or power supply demand overload and other factors will result is too more. The whole equipment load, high temperature.

4, design and construction: eddy current overheating due to improper, found in the actual detection, overheating due to eddy current should be to high.

5, poor heat dissipation slot: such as cable is too dense, air conditioning is insufficient accumulation of substation, the cabinet body ventilation adverse, equipment environment High temperature factors lead to overheating accumulated heat can not be eliminated, and speed up the insulation aging.

6, other reasons.
Detection of mechanical equipment
The heat source of rotation and drive mechanism from the “friction heat”, due to poor lubrication or component lead to mismatch and other factors, will have a lot of friction heat, causing the temperature rise, resulting in rapid mechanical grinding Loss damage or excessive vibration, the transmission efficiency decline lead to achieve precise control requirements. This kind of detection applications include electric Machine, bearing, coupling, pump, compressor, transmission device (a belt, a gear or chain) and other equipment.
Types of electrical Detection equipment By power plants, electric power transmission and distribution lines, substation, electrical room, control room, slot, distribution box and electrical equipment is Partition places, may include generator, overhead transmission line, transformer, circuit breaker, current transformer, voltage transformer, lightning arrester, the ratio set Tube, bus, reactors, capacitors, cables, wires, and all kinds of switch, switch, relay, or electricity The machine and the power equipment itself, may be the application of test to find out the abnormal issues important equipment.

IR LED for maintenance detection equipment

Infrared thermal imaging using infrared band signal detection object specific heat radiation of photoelectric technology, the signal is converted into available Human can visual resolution images and graphics, and can be used for calculating the temperature value with IR LED. Infrared thermal imaging technology to make human transcendence The visual impairment, thus people can “see” the object surface temperature distribution.The surface temperature of objects if more than absolute zero (0K) will radiate electromagnetic wave, with the change of temperature, the radiation of electromagnetic wave The intensity and wavelength distribution has changed, the wavelength range of 0.75 mu m to 1000 mu m electromagnetic wave between called “infrared”, While the human visual “visible” from 0.4 mu m to 0.75 mu m. Infrared transmission in the surface, will be affected by the composition of the atmosphere Substance (especially H2O, CO2, CH4, N2O, O3 etc.) absorption, strength decreased obviously, only in the short wave 3 mu ~5 mu m and Two bands of long wavelength 8~12 m has better penetration rate (Transmission), commonly known as the atmospheric window (Atmospheric Window), most of the infrared thermal imager is based on these two bands were detected, calculate and display the temperature of the object surface The degree distribution. In addition, because the infrared to great part of the solid and liquid material penetration ability range, so the thermal infrared Imaging detection is based on the infrared radiation energy measurement of the surface of the object oriented.Predictive maintenance test Predictive maintenance detection is the potential failure factors and pre detection diagnostic equipment, have the objective of maintenance work according to the plan. This maintenance test operation not only improve the reliability of equipment operation, and reduce maintenance costs and working time of equipment, reduce equipment Preparation of excessive maintenance problems. Infrared thermography technology also have non destructive detection, non-contact measurement, The intuitive observation, immunity to electromagnetic interference, quick measurement, high sensitivity characteristics, is the most effective predictive maintenance work.Abnormal equipment, usually show some signs, such as vibration, sound, electricity, light, temperature, pressure, different Measurement of other physical quantities, for finding and diagnosing the problem. Many equipment abnormal display may be in the early stage The temperature difference between the perceived, and infrared thermal imaging is a detection method of measuring temperature, thermal image and temperature will be measured Value according to the structure and properties of the device, to discover and diagnose problems, suggestions of improvement scheme.