In-depth Demand Report | Disassembling Outdoor Flood Light Kit

W hotel design inspiration for intelligence San Diego: by the waves beat you, after get up to see a setting sun, clear blue sea water and slowly coming of the night, may because of your unstable and makes you dizzy.

Into the hotel, deserve to act the role of diverse and not mixed and disorderly, color thick bar is very attractive, distinctive modelling of lamps and lanterns, restaurants or leaping orange or elegant color, W can always put all sorts of color coordination fuses in together, the overall looks messy, but it is gorgeous.









editor: gather

In the work of full color LED display screen, the function of driver IC is received in accordance with the agreement according to the data (

From receiving card or video processor, etc)

, changes in internal production PWM and the current time, output PWM current associated with brightness grayscale refresh, etc to light up the LED.

Driver IC and logic IC and surrounding of MOS switch IC, work together in the LED display display function and determine its rendering effect.

LED driver chips can be divided into general and special chip two so-called general chip, the chip itself is not designed specifically for the LED, but some has LED display part of the logic function logic chip (
Such as string and shift register 2)
。

Refers to the special chip and in accordance with the characteristics of LED and designed specially for the LED display driver chip.

LED is device current characteristics, namely on the premise of saturated conductivity, the brightness changes with the change of the current, not by adjusting the voltage at the ends of the change.

One of the biggest characteristic is to provide special chip so constant current source.

Constant current source can guarantee the stability of the LED driver, eliminate the LED flashing phenomenon, is the precondition of LED display shows high quality images.

Some special chip also the requirements of different sectors to increase some special functions, such as have LED error detection and correction of current gain control and current.

Drive the evolution of IC in the 90 s, is given priority to with single and double color LED display applications, USES a constant voltage driver IC.

Appeared in 1997, our country's first special LED display driver chip 9701, from 16 grey level crossing to 8192 grey level, realize the video what you see is what you get.

Then, in view of the LED characteristics, constant current driver to make the first selection of full-color LED display driver, at the same time, more integrated drive replaced 8 channel drive 16 channels.

In the late 1990 s, Japanese companies such as Toshiba, the Allegro, and Ti launched 16 channel LED constant current driver chip, at the beginning of the 21st century, China's Taiwan company driver chip and the production and use.

Now, in order to solve the problems of the small spacing LED display PCB wiring, some driver IC manufacturers and introduced a high integration of 48 channel LED constant current driver chip.

Driver IC performance indicators in the performance of the LED display, refresh rate and grey scale and image expression is one of the most important indicator.

This requires LED display driver IC channel between the current rate of high consistency, high speed communication interface and constant current response speed.

In the past, the refresh rate and utilization rate of gray-scale and is a reciprocal relationship, to ensure that one or two indicators can be more outstanding, will be appropriate at the expense of the rest of the two indicators.

To this end, a lot of LED display, in practice it is hard to kill two birds with one stone, either refresh is not enough, it's easy to have a black line under high-speed cameras filming, either gray level is not enough, color and brightness.

With the progress of driver IC manufacturers, has been a breakthrough on three highs, have been able to solve these problems.

In the application of full color LED display screen, in order to ensure that the user for a long time in the comfort of the eye, high low light grey become a test driver IC performance is the main standard.

The trend of the driver IC 1, energy conservation as a green energy, energy conservation is the eternal pursue of LED display, is also a important considerations drive IC performance standards.

The following 8 v;

2 it is through the optimized algorithm for IC design and reduce driving IC operating voltage and current operation.

2 v voltage low twist, improve the utilization ratio of more than 15% of the LED constant current driver IC, using 16% lower than normal product of the power supply voltage to reduce heat, to greatly improve energy efficiency for LED display.

2, integration with the LED display pixel pitch drops rapidly, per unit area to SMT packaging components with geometric ratio growth, greatly increase the module density on the surface of the drive components.

9 LED, for example, small spacing 15 of the 160 * 90 modules need 180 constant current driver IC, 45 manager, 2, 138.

So many devices, make PCB wiring available space is very crowded, increased the difficulty of the circuit design.

At the same time, so crowded components, easy to cause such problems as poor welding, at the same time, it reduces the reliability of the module.

Driver IC less dosage, PCB larger area, demand from the application of reversed transmission drive IC must be on the high integration of technical route.

At present, the industry mainstream driver IC vendors are successively introduced a high level of integration of 48 channel LED constant current driver IC, the mass of peripheral circuit are integrated into the driver IC wafer, can reduce the complexity of the application side PCB design, also avoid each manufacturer engineers design capability or arising from the difference design problems.


YanZhiXiang



the window of the science and technology,

in addition, solar street lamps in the process of actual use exactly how long will it bright, it is very important, and the height of the solar street light light pole, the distance between the street lamp, and the width of the road, all of these things is to consider in them, only a comprehensive consideration, to be able to solar power for the selection of relevant, and in the process of installation, you also want to consider a solar street light radiation surrounding some of the light source, integrated a series of factors to consider, in this way, you will be able to understand the various installation details, reporting to the related manufacturer specific figures, and then they will recommend suitable for you according to your actual situation of solar street light.

Intelligent dimming system flexibly adjust light output to reduce the energy consumption of the traditional high pressure sodium lamp, can achieve the dimming control of a small scale, such as closing a side or interval closed street lamp, inevitably bring change in the form of lighting, easy to cause potential safety hazard.

LED street light,


intelligent dimming system flexible adjustment light output to reduce the energy consumption of the

traditional high pressure sodium lamp, can achieve the dimming control of a small scale, such as closing a side or interval closed street lamp, inevitably bring change in the form of lighting, easy to cause potential safety hazard.
LED street light 0 - can be realized

100% continuous adjustable light, can be adjusted according to the environmental light and traffic light output, to guarantee the quality of the lighting at the same time reduce unnecessary power consumption.

Development of semiconductor lighting system of zhongshan university research center of the LED street lamp intelligent dimming system can easily control the working state of the LED, and by changing the drive current to control the brightness.

In later into the wee hours, for example, by reducing the whole lamp current or close the interior of the lamps and lanterns of LED light emitting component to achieve low power operation, to achieve the effect of energy saving.



semiconductor lighting system of zhongshan university research center also control the Zigbee wireless communication technology application on the LED street light system.

Zigbee wireless control system of the starting point is hoping to develop a low-cost wireless networks are easily, with a simple protocol stack is compact, save electricity, reliable characteristics such as large capacity, short time delay, network (
Figure 3)
。

Zigbee transceiver module integrated in every LED street lamps, and by way of relay, put all the information collected on the terminal, so as to realize the terminal to the operating condition of each LED street lamp for effective monitoring, the function of control system, troubleshooting and guard against theft.

Thermal



optimize cooling and thermal management control system

LED under the forward voltage, overcome p - driven by electron in an electric field

N n junction of the electric field at transition to p area with p and cavitation occurs inside the compound.

Due to the transition to the free electrons is higher than that of p p area area of valence electrons energy, electronic back to lower energy state for the compound, excess energy release in the form of photons, the light of the radiation out only after the chip itself and encapsulating semiconductor media medium to reach the outside world.



considering current injection efficiency, radiation light quantum efficiency, external factors such as light extraction efficiency and the chip for 100 lm/W leds only about 30% of the electric energy into light energy, and the rest of the energy is converted into heat energy, the temperature rise of the LED chip.

For the LED chip, if the quantity of heat cannot effectively out, can lead to raise the temperature of the chip, the thermal stress caused by non-uniform distribution, chip light-emitting efficiency and phosphor efficiency decline.


with p -

N junction temperature rise, the emission wavelength of LED chips red shift will occur, resulting in a decline in YAG phosphors excitation efficiency and the total luminous intensity is reduced, the white light chroma drift.

When the temperature exceeds a certain value, the failure rate of the device will be rising exponential law.

Device temperature rising every 2 ℃, reliability will decline by 10%.
In order to guarantee the life of the device, p - general requirements
N junction of junction temperature under 90 ℃.

When multiple leds dense array or integrated packaging system heat dissipation problem is more serious.

Therefore solve the problem of heat dissipation has become a precondition for LED lights.



how to improve the LED street lamp cooling ability is the core issue of LED encapsulation and LED street lamp design.
LED street light heat dissipation problem into p - chip
N junction to the epitaxial layer;
Epitaxial layer to the packaging substrate;
Packaging substrate into three layers from the outside environment.
The three links constitute the heat conduction channel.

For heat dissipation problem of LED, semiconductor lighting system of zhongshan university research center, respectively, the following all aspects of optimization design was carried out on the heat dissipation and thermal management systems.


p - chip

N junction to the epitaxial layer cooling: in the process of the growth of gallium nitride materials, improve the material structure, optimizing the growth parameters, the extension of access to quality, improve the device internal quantum efficiency, radically reduce the generation of heat, to speed up the p - chip
N junction to heat conduction of the epitaxial layer.



epitaxial layer to encapsulate the substrate heat: on the chip packaging, by using the flip chip structure, eutectic solder packages (
Figure 4)
, metal structure of circuit board.

On the device packaging, select the appropriate substrate material, such as metal printed circuit board (
MC -
PCB）

, ceramics, composite metal substrates such as thermal conductive performance good packaging substrate, to accelerate heat from escaping through the epitaxial layer to encapsulate substrate.



packaging substrate to the external environment of the heat dissipation: the LED street lamp is generally the high-power white LED array by means of reflow soldering welding on the metal substrate, and then install the metal substrate closely in bulk on the heat dissipation fin of aluminum, copper materials.

The heat generated by the high power white LED by metal substrate is passed on to the heat dissipation fin, the use of natural convection or artificial forced convection cooling way to achieve.



semiconductor lighting system of zhongshan university research center for high-power integrated packaging heat large, concentrated light source module, the characteristics of high-power integrated encapsulation light source module is installed on the mean temperature plate, using the mean temperature plate fast diffusion heat performance of LED the heat generated by the rapid lateral diffusion;
Also USES the heat pipe in heat dissipation fin part (
Straight type of loop heat pipe and pulse heat pipe and heat pipe)
To reduce the strengthening heat transfer and reduce the thermal resistance (
FIG. 5)
；

In the cavity of the LED street lamp to produce artificial forced convection way to strengthen the convection.

Solar street lights are the main part of poverty alleviation projects. At present, almost all poverty alleviation projects in inland China are carried out from mountainous areas. Solar street lights can solve many problems in people's lives; some remote mountainous areas in the country have normal power and Lighting issues, because remote mountainous areas are far from urban power points, while rural solar street lights use daytime lighting to convert light energy to use power and store it in batteries, then wait until night to release power to illuminate. So what is the wholesale price of solar street lights? This

Generally, it is recommended to use 5 watts or 6 meters 30-watt solar street lights for rural solar street lights, but each customer's needs are different, and it is impossible to judge the wholesale price of solar street lights uniformly due to the height and thickness of the pole, the Power, the size of the solar panel, the battery, and most importantly, the length of time it is illuminated, will determine the price of a solar lamp post.

Actually, for the purchase of solar street lights, it is impossible for manufacturers to provide users with a unified wholesale quotation for solar street lights due to different system configurations.

1. Due to configuration reasons, the price is different

During the installation of solar street lights, due to the influence of weather and environmental factors on the installation area, the configuration of the public lighting system is different in different areas.

Due to the high configuration of some street light systems and the low configuration of some street lights, it is difficult for manufacturers to provide a unified price, so the general manufacturers of solar street lights will give a general quotation for the system, and cannot accurately give the entire street light offer.

2. Different prices caused by production technology

For different manufacturers of solar street lights, due to the difference in production technology, the quotations of street light systems also vary according to solar street lights.

Although there is little difference in the production price of street lights from different manufacturers, different production techniques will result in different quality of street lights. Therefore, when purchasing solar street lights, it is best to go to the factory for on-site inspection to ensure the quality of the street lights.

Finally, in order to ensure the purchase price of solar street lights, when setting up the street light system, it is only necessary to inform the manufacturer of solar street lights of some detailed parameters, in order to realize the installation of street lights with guaranteed quality.

The wholesale price of some solar street lights is lower than the market price, which usually confuses consumers and affects the speed of their choice. When customers actually choose and install these low-cost solar street lights, they will find that the expected results cannot be achieved. It is recommended that everyone choose products from regular solar street light manufacturers.