LOOK AT THE LED FROM DIFFERENT PERSPECTIVES

 Structure and properties of materials:

1,The size of chip. The same kind of chip, the larger the size, the higher the brightness, the stronger capacity, stable performance, the better, of course, price is also relatively higher. Chip size is now mainly: 9MIL, 10MIL, 12MIL, 14MIL and 23MIL so on.
2, The light emitting efficiency.LM emitted value from per watt is called luminous efficiency. This is an important standard to judge whether the energy-saving for LED. Incandescent lamp 14.4LM / W, fluorescent lamp is about 51LM/W, fluorescent lamp is about 51LM/W, the neon lights around 43LM/W, LED is up to 150LM/W, Note that only the white LED can reach such a high light efficiency, red, yellow, blue generally relatively low.
3,Service time. The LED service time everyone thinks is 100000H.In fact,the  LED product in 10 or 20 years before it can be up to 100000 hours, the best LED life is expected to only 50,000 hours by far. Incandescent 1000 hours, 2000 hours fluorescent, neon 10,000 hours. The so-called 100000 hours,but scientists in the laboratory at room temperature estimates obtained.due to differences in the package equipment used and production of technical differences and different management or different users…. the resulting in life is not the same. SMD LED, life can reach 40,000-50,000 hours; Piranha LED, life of 30,000 hours, in-line LED, life is 10,000 hours. Of course, with the chip and package technology progress these data will gradually improve. LED life is when the luminance of LED is 70% when the original brightness, we determine the LED life so far. LED life is when the LED luminous intensity is 70% of original brightness time, we determined that the LED life is over.
4,The quality of circuit board. LED of the same quality, the quality of the board will have an important impact on the life of the LED
The Circuit board is divided into aluminum, fiberglass panels, half glass plates, cardboard. The best quality aluminum plate, the best cooling effect, but the cost is too high, Follow, we will talk about Module, the color of piranhas, straw hat module is generally used cardboard or half glass, half glass patch series for general use or the glass plate. Colorful and full-color series have at least a half glass.
5,Full color range of IC . IC has dozens of different IC, the performance, stability and price are different, resulting in the finished product cost is different.
6,Solder：solder brightness is full, here is no cold solder joint, This affects the thermal and stability

SOME MATTERS COUNTER LIGHT BAR INSTALLATION SHOULD BE NOTED

Several points counter light installation should pay attention
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Install conter strip(lpd6803 led strip)
Install conter strip1

1, can not be pressure. Light bar counter made ​​of aluminum plate, pressure will cause the deformation

2, do not destroy the cable when connecting the circuit board. Connecting line for advanced tungsten silver wire, it’s good electrical conductivity.

3、Drag the product the ground above. to avoid scratching or damage the shell.

4, Please note that electricity standard(product’s paramtmer) when test the product first time. And should be strictly in accordance with the positive and negative power to connect cabinet lights at the correct voltage.

To avoid damage to the cabinet lamp.

5、“For many are lamp in couter, please ensure that parallel cabinet lights and power supply, if the series is too long. it will lead to unbalanced for the voltage.

Brightness is different, does not recommend more than 4 meters for a tandem unit, please ensure that the maximum power to echo channel is within the maximum power adapter.

ABOUT CALCULATION OF LED STRIP

Matching calculation and power supply with power LED strip is very familiar for city lighting engineering. following we will talk about the process of strip project plan. calculate the number of LED strip lamps for the project. It should be noted that the LED lights can be divided into three groups cut using. 60 per meter LED lights with LED’s in each length of 50mm,30 per meter LED lights with LED’s in each length of 100mm . Understand this then you can calculate the actual number of LED lights need. The general reserve length of about one meter is good. so as to avoid excessive waste.Because the buy LED lights is not distributing power, so we need to calculate the required power supply. then matching power supply. Power LED lights with different so for the power matching to carefully choose.for example if the purchase is 5050LED lights, matched power is 12V, the 4A by specification, then a power supply can only take 6 meters 5050LED lights.Because 5050LED lights per meter power is 7.2W, a total of 6 meters of 43.2W, while the power supply rated power is 48W, is generally not recommended to use the power of full load, because that power of life for a great impact, suggest to use only the power of 95%. If I need the 100 metres, the 4A power corresponding to be equipped with at least 16pcs.

LED lights with controller: for RGB lights bring that effect must be equipped with a controller only, for the lpd6803 led strip must be equipped with the controller to have effect, but a controller can control the LED lights with lengths from 5 meters to 20 m range, which one is selected as controller specifications.Thus, in the purchase of RGB lamp belt, also need according to control length controller in addition to controller, or purchase another RGB amplifier (each amplifier can be extended to 5 meters) Do not mistakenly think that a controller can achieve the control requirements for all RGB lights, this is the wrong point of view. For example, the purchase of 100 meters of RGB lights, while the controller selects a conventional controller, which controls the scope of each controller is 5 meters kind. Then 100 meters of RGB lights need to be equipped with the RGB controller 20 pcs, or buy an RGB controller, buy another 19pcs amplifier
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SHARE–LED ADJUSTABLE LIGHTING

In the lighting industry, the people often have a misunderstanding for LED light dimming that compared to other light sources (fluorescent, metal halide and sodium, etc.).the dimming LED relatively easier. But the reality is the application of LED light dimming technology Is not satisfactory for engineering .why is this? To answer these questions, we must first understand the volt ampere characteristic of LED.then to help readers to understand and master the LED light dimming and its application.
So from the volt-ampere characteristic of LED, we can know that LED light dimming can’t simply by reducing the input voltage and input current of LED to achieve, in addition to LED of a sine wave waveform is different from the incandescent lamp, therefore can not simple obtained by changing the conduction angle,so as to achieve changes in effective value (effective dimming) purposes.

LED Triac Dimming:
Ordinary incandescent and halogen lamps usually adopts SCR dimming. Because incandescent and halogen lamps is a pure resistance device, it does not require the input voltage is a sine wave, because it is always the same between the current waveform and voltage waveforms, so no matter how sine wave voltage waveform deviation, as long as the change of the input voltage, you can be dimming(adjust the light).However triac dimming to adjust the LED light source to produce unexpected problems, that is, the LC filter input will make oscillation with SCR. this oscillation for incandescent lamps is insignificant(lamp makes the eyes do not see this oscillation), but to drive power will be the production of LED audio noise and flicker. non sinusoidal waveform will produce serious interference signals in the circuit (EMI) power network pollution, serious will make the grid paralysis.

Hereto, you might ask: ” to reduce the voltage or current and the SCR dimming methods are not suitable for LED light dimming, then in what way is the most appropriate?.”

PWM (pulse width modulation) dimming can be a good way to solve the above problem, because LED is a diode, it can achieve fast switching, switching speed which allows may reach microsecond above, is unmatched by any light-emitting device. Therefore, as long as the power source into a constant current pulse, with the method of changing the pulse width,it is possible to change the brightness, this method is called the pulse width modulation (PWM) dimming method.This is dimming switch like a up to microsecond or switch gate, because the gate switch frequency soon,we are unable to recognize their state of the switch with the naked eye the result is that we can only pass much water downstream to recognition speed its switching frequency. In addition, as the gates flow changes the duty cycle of the output (effective flow rate), without changing the instantaneous pressure and the instantaneous water flow rate, so that the gates of microseconds up to a switching operation will not affect more than the work of flow, because the moment instant pressure and instantaneous flow does not change, change is the electric power generation of loader. and so on PWM (pulse width modulation) dimming method does not change the input instantaneous voltage and instantaneous current of LED PN junction, to change the duty cycle of the output current, thereby changing the brightness.

Thus, LED PWM (Pulse Width Modulation) dimming method has the advantages as following:

1, does not have any LED chromatography offset, because the LED is always working at full amplitude between current and 0V.

2, there is a very high dimming accuracy, because the pulse waveform can be controlled to a very high accuracy, so it is easy to achieve 1/10000 accuracy.

3, even, to dimming in a wide range, also won’t happen the flicker phenomenon. Because does not change the constant current source condition (step-up ratio or step-down ratio), the more impossible to geted the overheating problems.

4, can be with the digital (DALI / DSI / DMX 512 ) control techniques of combining, because the digital control signals are easily converted into a PWM signal.

Although LED PWM (Pulse Width Modulation) dimming has many advantages, but need to pay attention to the following two questions:

1,A pulse frequency of choice, because the LED is in a fast switching state, if the operating frequency is low, the human eye will feel flashes. To take full advantage of the human visual residual phenomenon, it should be higher than the operating frequency of 100Hz, preferably 200Hz.The heavy rain was the cause of the flood.

2, The dimming was the cause of whistling, although the human eye can not detect more than 200Hz, but they are all up to 20kHz range of human hearing. At this time it is possible to hear the slightest sound. There are two ways to solve this problem, one of the switching frequency up to 20kHz or more, out of the range of human hearing. Another way is to find sound devices and to be deal with.
the control signals are used DALI (digital Addressable lighting interface) technology, combined with digital lighting control system, fully digital LED control product line. have been very good to solve the above problems, Most important feature of DALI (Digital Addressable Lighting Interface) technology is a single lamp with separate address, or any single lamp lights set precise dimming and switch control via DALI system software,on whether those in strong electric lamps or different loop circuit lamps. Other words DALI system software has strong individually addressable for the led which same or a different electrical circuit loop.enabling individual control and arbitrary grouping. This idea brings great flexibility for lighting control,The user was delighted to be make the lighting solutions designed to meet their needs as required, even after the end of the installation,it’s can still modify any control requirements.Now, the DALI interface is not only limited to light adjustable fluorescent lamp ballast,electronic transformer tungsten halogen lamp, gas discharge lamp electronic ballast, LED uses the DALI interface dimming;control equipment also includes: a radio receiver, a relay switch input interface. All kinds of button control panel, including LED display panel has a DALI interface, which will make DALI applications(or ) more and more widely, the controller to expand from an office minimum to multi room building, expanding from a single store to the Stars Hotel.

Summary:
Although at this stage of the LED dimming applications was chaotic, and there are still some problems and obstacles, but there is no denying the fact that LED dimming prospects are bright. As long as we maintain a cautious attitude, develop science and psychology responsible LED dimming technology, to LED dimming technology promotion, to make good use of the LED dimming technology, then the LED dimming products bring us benefits, to bring the benefits of lighting industry, to bring the benefits of human beings in the not too distant future.

LED LIGHT SOURCE COMPARED WITH CFL

Can you replace the CFL with a brighter one?

From the beginning, we will start by discussing- different light resource products.

The incandescent lamp also went to called the electric light bulb, its working principle is the current through the filament (tungsten, melting temperature reached to 3000 degrees Celsius) it generates heat, meanwhile it generates light. the light is bright,from strength to strength The filament temperature is high,So called incandescent lamp.in fact , The Incandescent lamp, a large amount of electrical energy will be converted into heat, only a few (probably less than 1%, had not been calculated) can be converted into useful energy. So the power of incandescent lamp is more.

a fluorescent lamp：   fluorescent lamp or fluorescent lamp, its working principle: In a few words the fluorescent lamp is discharge tube that was involved in gas。One has process to gas discharge to releaseing ultraviolet   (main wavelength as 2537 =2537 × 10-10m). Electric energy can be converted into about 60% UV consumed. Other energy is converted into heat energy. It is generally the ultraviolet light into visible light efficiency is about 40%. So the efficiency of fluorescent lamp is about two times the same power tungsten filament lamp. （60% * 40% = 24%）.

LED lamp (Light Emitting Diode) also known as light-emitting diode, is a solid state semiconductor devices, can be directly converted into electricity to light.

LED English as a light emitting diode, LED light-emitting diode lamp beads is the abbreviation abbreviation LED, which is a popular title.

Especially The led cob or ir led strip  tunneling is more and more popular during recent years,
LED Modules are the latest in efficient mounting systems for LED displays. Modules are compact in size, may contain several LEDs (series-parallel connection)encased in a package.Due to the integrate of the semiconductor light-emitting diode chip technology , LED photoelectric conversion efficiency to be improved, especially in high-power LED, because of its high power ,High-Power LED Modules demand for quality and Mate- rials Handling is higher. to find out more about LED products

Equivalent Wattages of LED and Incandescent BULBS
difference between led and cfl bulbs1

LED bulbs use 85% less energy and last up to 20 years
longer than incandescent bulbs.
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Light Bulb-LED&amp;CFL&amp;Halogen&amp;Incandescent Comparison Chart
difference between led and cfl bulbs2
difference between led and cfl bulbs

COMPARISON OF PIRANHAS, SMALL STRAW HAT AND SMD

Comparison of piranha LED , small straw hat and SMD According to the type of sub package, now on the market there are three main types of cars for LED indoor light design of the LED lamp: piranha LED , small straw hat and SMD. Three package types LED, light-emitting principle is the same in fact, both use a blue light emitting chip, filled with yellow fluorescent powder, blue light by refraction and internal mixing phosphors to produce white light, the external use of epoxy resin, resin have protective chip and prism effect, the angle of the light emitted can be a control.Because the light emitting principle is same, but the brightness is different, to compared the three kind of led. The piranha LED most brightness, in turn is led straw hat and last is SMD. which is the difference between SMD and led straw and brightness.Now To have a practical understanding of the three kinds of LED on the led market with the most.

Fig. 1 piranha LED

Fig. 1 show as  piranha LED  Piranha LED package is one of the largest in this three types. square, has four legs,is one of the three best package heat dissipation capability.The LED heat through the internal structure(distribution outward from jointing pin) of its own. Piranha LED as bigger in size, the thermal conductivity of metal inside it big, and he has four legs(jointing pin), It is because the Piranha LED has better ability of heat dissipation, his work current of LED is slightly higher than the other two, can reach more than 30mA, while the small straw hat with the normal operating current SMD is about 20mA.In addition,Piranha LED package size is relatively large, it can be integrated in a small reflector inside the package, which is to improve the brightness of Piranha LED is also very good, so the Piranha LED is three packages in a single brightness highest. Another look at a small straw hat (Figure 2) small straw hat LED is circular, looks like a straw hat.

       
Figure 2                                               Figure 3

is a small straw hat and a Piranha LED put together photographs, the photos can be seen that small straw hat size is much smaller than the
Piranha LED , no structure reflecting cover, and only two legs(jointing pin), from the structure, thermal performance worse than the Piranha LED , so the small straw working current is lower than the Piranha LED , generally work at about 20mA, so its service life is greatly reduced.Finally, take a look at SMD, SMD is the abbreviation of Surface Mounted Devices, meaning the surface mount device, SMD does not mean a particular LED，it’s just the form of a package, a variety of surface mount components can be called SMD, such as SMD resistors, SMD capacitor, SMD manifold, etc.so the SMD is just a collectively. the same is There are a variety of differences between LED SMD package, for example,such as 0805, 1206, 1210 etc.. So some people say that SMD is a substitute of LED in the future,such a thing is very problematic, because the SMD is just a collectively, how to replace?And now we generally think of the 1210 package

( Figure 4 –some people also known as 3528 to 1210) namely SMD LED, the Piranha LED , a small straw hat with SMD 1210  put together photos.we can see, the SMD LED package size is even smaller than the small straw hat. The greatest advantage of SMD LED package — its small package size in the modern electronic products become smaller, the internal space more and more small, the small size of the components is very competitive. because of its small size,SMD LED because of its small size, meanwhile welding after it is structure of a fully attached to circuit board, so the cooling performance is the worst than the other two, the SMD LED without resin lens, it’s brightness is much lower than the Piranha LED and small straw hat. but then (again), because of the so-called SMD, refers to surface-mount devices, as long as the surface mount, called SMD, so strictly speaking, there are more bright SMD LED, is 1W, 3W or 5W high power SMD LED, shown that some 1W or 3W high power LED as shown in Figure 5 is 1W or 3W power LED , because they are surface-mount packages, so they can be called SMD.

Figure 5

In the above description, we have repeatedly mentioned in one word: radiationPerhaps some people will ask, LED is not known as the cold light source? Not to say that LED does not heat it? We used to have customers get our products after asking us, how does it feels a little hot an open lamp. In fact, When the situation described by the if clause is not presupposed to be false, electronic products all work to be hot, single bright, you might not feel too much heat, but when many LED together, operating at the same time, it comes out of the heat is quite impressive. but relative to the incandescent light bulbs, his fever is much smaller. In the design of LED lighting, heat dissipation design is a very important,because all the LED has a bad light Luminous Flux Depreciation,  Luminous Flux Depreciation with LED working temperature is great relationship. so our products in the design of circuit boards, will pay much attention to the heat problem.

LED LIGHTING DRIVER IC(LPD6803) INTRODUCTION

LED as the display, due to its advantages of high luminous efficiency, long service life, easy to control.has increasingly been used in more fields Especially in now began to be widely used in the lighting system of city / stage。This paper describes the types of LED lights, LED lighting control dedicated chips, the hardware and software design ideas design ideas .Color image point: in order to make the LED light color display is required by at least two or more different LED colors form a LED pixelｓ. RGB LED collocation according to the brightness and gray level demand can have a variety of combinations, such as: 1 pcs red LED + 1 pcs green LED+1 pcs blue LED can be display 256 gray color. The LPD6803 is specially designed for LED lighting system driver chip, built-in-PWM, can generate three-way constant current driving and gray adjust output.

Technical features:The multi- color pixel dot composed of led tube. each pixel changes can be independently produced 256 color.

Application environment: overpass, river fence, decorative lighting of building exterior wall in different places.Multi-color pixel dot compose of a module. Can be independent controlled of echo pixel dot.

Application environment: bar, KTV, stage. As decorative lighting floor or walls.LED lighting control chip introduced LPD6803 is designed for LED lighting driver chip, simple control.

Function description:

The built-inA. oscillator,The scan does not need that the control board to provide scan clock.The B. two control lines, control and simple wiring.C. data clock can reach 25MHz, you can get more cascaded output.LED lighting control system hardware design ideas

LED lighting control system mainly consists of the pixel drive unit and control panel designed in two parts.

The 1 display unit design of the driving point How to achieve the pixels showing a different color, mainly rely on the principle of human visual intermittent inert,using each pixel to produce different duty cycle for the mixing of colors. The design of LED color display case mainly depends on the LPD6803 automatic output 3 channel 256 gray color to achieve color display. The controller only needs to transmit each pixel scanning duty cycle data .
The drive unit design diagram below, suitable for color LED guardrail tube, LED floor tile applications.
the number of red, green and blue three-color LED can be multiple. Single LED cascade mode can be used in series or parallel way to achieve, in the design is you need to The hardware is only provided the design of a control system for your reference, To be sufficient some basic conditions needed for an ordinary LED lighting system.According to the actual system, can choose ARM, CPLD, accelerate the speed of transmission data and USB communication, SD card storage requirements.Hardware design of objective description(consider the voltage / current and external drive. Data output cascade connect to the next module input will achieve a cascade system.

  Hardware design of objective description

U1: use MCU51 microcontroller, if the system drive pixel cascade number not much and don’t need to do image animation too complex display case. The MCU even can choose 2051 pin low, low price of MCU.
JP1: with LPD6803 serial sequence interface for output, only DATA, CLOCK, GND can meet the requirements of data transmission.
U4: SPI FLASH, for storing program data. According to the need of the system can be used to design multi chip FLASH memory chip. SPI FLASH now relatively high capacity can be done 4M bits.
U6: as the communication interface, used to show content and transmitting program data system host communication control. And for the upgrade program.
Driven design software 3

The following to drive the individual pixels to illustrate the data transfer mode. lpd6803 led strip is an automatically generated 128 level!