月份：2012年8月

residential led lighting systems and led drivers

Flyback LED drive GM, because the structure can be used for input voltage higher or lower than the required output voltage. In addition, when the flyback circuit operating in discontinuous inductor current mode, able to maintain a constant LED current, no additional control loop. The circuit described in this application note is based on highly integrated MAX16802 PWM LED driver IC.

Application

* LED track lighting

* Universal LED lighting

Feature

* 10.8V to 24V input voltage range

* Single 3.3V LED power supply, provide 350mA (typical) current (LED configuration structure, designed in accordance with the design steps)

* 29V (typical) anode to the maximum open circuit voltage

* 262kHz switching frequency

*-By-cycle current limit

* On / off control input

* Allows the use of low-frequency PWM signal to adjust the brightness

* You can adjust the circuit to adapt to the various forms of series, parallel LED configuration

Typical Application Circuit
Note: + VLED-VLED and LED lights connections, do not give circuitry.

Component list

Circuit topology

* Open-loop, non-isolated flyback LED drive is very general and easy to use. It has a number of advantages, and very popular. These benefits include:

* The need for an external control loop to adjust the LED current

* Non-continuous inductor current transfer reduces EMI emissions

* Lower switch conduction losses

* Simple circuit design process

LED voltage can be higher or lower than the input voltage

* A wide input voltage range

* Easy access to the PWM dimming signal

The biggest advantage is the cost of the following shortcomings:

* The LED current is limited by component tolerances, for example, the inductor and galvanometer comparator propagation delay

* Non-continuous inductor current mode, so that the topology is more suitable for low power applications

Design steps

The most important parameter is the LED current. The high-brightness LED current is generally a few hundred mA. In order to extend the working life of LED, the current must remain constant; power is essentially a current drive. There are several ways to achieve a simple and low-cost solution: using a dedicated current mode PWM controller IC, for example, while the MAX16802 is. The advantages of the device is:

* A high level of integration – required few external components

* Up to 262kHz switching frequency

* Tiny 8-pin μMAX

* Smaller galvanometer threshold, to reduce losses

* Accurate oscillation frequency, to help reduce the LED current changes

* On-chip voltage feedback amplifier can be used to limit the output open-circuit voltage

Given the LED parameters are:

Step 1: calculate the minimum input voltage, the best approximation of the duty cycle:

Where Rb is the ballast resistor R11 in the application circuit in this application is set to 1. VD is the forward voltage drop of the rectifier diode D1.

The known values ​​in the above equation:

Step 2: Calculate the peak inductor current approximation:

Kf is a critical error coefficient, set at 1.1.

The known values ​​into the above equation to get:

residential led lighting systems and led drivers

Step 3: Calculate the required inductance approximation, and select the less than and closest to the calculated value of the standard inductance:

Where L is the L1 in the application circuit; f is the switching frequency is equal to of 262kHz.

The known values ​​into the above equation to get:

Below this value, the closest standard value of 10μH.

Step 4: the process of passing through the flyback output power:

The output circuit power dissipation is equal to:

According to the principle of conservation of energy, the two formulas should be equal, you can get a more accurate peak inductor current:

Where L is the actual choice of standard inductance values.

Known values, we can get:

Step 5: Calculate the galvanometer resistance, derived by R9 and R10 in parallel; calculate the voltage detection voltage divider (if needed), consisting of R6 and R7.

The MAX16802 is the current limit threshold of 291mV. Therefore, R9, R10, R6 and R7 to meet the inductor peak current calculated in step 4.

Upon completion of this step, you can get the value of the various components of the application circuit, The circuit provides 12V, 350mA output. Because of the parasitics, the resistance value (R7) need to make proper adjustments to get the desired current.

Step 6: R1 and R2 are optional. They are used to adjust the + VLED to 29V. This is very useful output unexpected open. If the partial pressure of the above components, the output voltage is likely to rise, resulting in damage to the device.

Components C1 and R5 is optional, used to stabilize the voltage feedback loop. For the current application, you can not use these components.

residential led lights and OLED Use

OLED and led lights, also known as OEL (Organic Light-Emitting Devices). This device has a self-luminous, clear and bright, thin, fast response, wide viewing angle, low power, low cost, simple manufacturing process, characteristics of its inception, has been regarded as the most promising after the following LCD display. Currently, cellular phones, personal assistants (PDAs), digital cameras and other areas, OLED has been widely used, but very strict requirements for OLED power bias circuit, generally require high efficiency, small size, light weight the step-up transformer step-up transformer should also have good electromagnetic compatibility.

The MAX8570 is a MAXIM company launched the OLED step-up transformer chip. It is not only advanced design, perfect function, and the external circuit is simple, very flexible to use, design OLED power bias circuit is an ideal device.

Characteristics and working principle of the MAX8570 converter The MAX8570 converter characteristics

The MAX8570 converter main features are as follows:

(1) The chip power MOSFET, energy-saving circuit, control logic circuit and protection circuit integrated to simplify the peripheral circuit design, reduce costs, enhance system reliability;

(2) Working frequency up to 800kHz, allows the use of miniature table-mount components;

(3) ultra-low power consumption: quiescent current is 25mA, in True shutdownTM mode, current consumption as low as 0.05μA (typical);

(4) open-circuit protection to prevent the output capacitor and load damage;

(5) allows the use of the battery, the output voltage up to 20V, to meet the high voltage requirements of the OLED power bias circuit. working principle

(1) control mode

Figure 1 shows the internal block diagram of the MAX8570. When the MAX8570 power its chips inside the P-channel MOSFET on, the power supply voltage VCC through the inductor L1 is divided into two: one sent to the drain of the internal N-channel MOSFET, another path VD1 to C4 charge. When the N-channel MOSFET on, the current flowing through L1 gradually increases from zero, while the electrical energy stored in L1, once the current limit is reached, the N channel MOSFET turns off, L1 current by VD1 the load. In the way of the switching frequency will vary with the size of the load and supply voltage of up to 800kHz.

(2) shutdown (SHDN)

SHDN pin is pulled low, the device will enter the True shutdownTM Mode (off state), in True shutdownTM mode, the circuit’s current consumption as low as 0.05μA output and the input is disconnected, the LX pin is in high resistance state in the conventional boost converter circuit, the converter shutdown, the output and input will always be through the inductor and freewheeling diode connected to the load to draw some power from the input. The MAX8570 converter with True Shutdown, in True shutdownTM mode, it will make use of a P-channel MOSFET switch to disconnect the input and output, thus eliminating the shutdown, the power drawn from the input side.

residential led lights and OLED Use

(3) separate to the inductance power supply

Can be a separate supply of the IC and the inductor, the inductor supply voltage range of 0.8-28V, as shown in Figure 2 is a separate application to the inductor supply circuit, this circuit structure of the SW pin should be vacant, so that the power supply directly connected inductance, then output and input is disconnected, but no longer shutdown shutdown, the output voltage than the low inductance power supply voltage one diode drop.

(4) soft-start

When in True shutdownTM function, the circuit will slowly open the gate of the internal P-channel switch, to be fully open SW, the internal N-channel switch turns on, so to avoid inrush currents when VFB is lower than 0.5V , the internal N-channel switch off-time from 1μs to extend to 5μs, to control the inrush current.

(5) open-circuit protection

Open-circuit failure occurs when the upper feedback resistor or external diode The MAX8570 converter will immediately stop switching, in order to avoid too much damage to the output filter capacitor and load output voltage.

OLED power bias circuit design

The limit the current settings

Design, according to the following formula to estimate the value of the limiting current:

Where, POUT (MAX), maximum load power; VBATT (MIN) is the minimum supply voltage; POUT (MAX) for the maximum converter output voltage.

The output voltage setting

The MAX8570’s output to GND is connected between a resistor divider between the point then the FB voltage divider ratio determines the output voltage (the voltage adjustment range for the VCC-28V), the range of R2, 10-600KΩ So according to the following formula R1:

In order to improve the accuracy of the output voltage, VFB 1.266V; value of VOUT VCC to 28V, the design should be to ensure minimum bias current flowing through the feedback resistor 2μA.

The inductance of the Select

The inductor is a key component of the boost converter, its value directly affects the size of the normal work of the entire circuit. If you need to pursue a high-performance, the best choice for low inductance and inductance, MAX8570 work in the lower frequency, the inductor will produce magnetic saturation, causing ripple current increases or damage to the inductance, it is in the choice of inductance , according to the output current The MAX8570’s operating frequency of the inductor, the inductance of the rated current and ripple voltage conditions to the decision here Recommended inductor values ​​range from 10-100μH.

The diode of choice

Diode switching losses to a fifth sixth of the total system loss is a major factor affecting the efficiency of the boost converter, including forward losses and reverse recovery loss, and recommend the use of a fast recovery time and forward voltage small drop of the Schottky diode, the rated current value should be greater than the peak switch current, reverse breakdown voltage greater than the output voltage. The Schottky diode MBR0520, MBR0530, ZHCS400.

The capacitance of the Select

The output capacitor can maintain the output voltage can also smooth the ripple voltage due to MOSFET switch (N-channel MOSFET on the output capacitor to the load). Therefore, under the premise of ensuring sufficient bandwidth, you should select ESR (equivalent series resistance) ESL (series equivalent inductance) is small, high pressure value of the output capacitor such as X5R or X7R dielectric material in ceramic capacitors, most applications, circuit design, its capacity is desirable 1μF.

The input capacitance is mainly used to filter out the ripple voltage in the power supply, it is recommended that ceramic capacitors with X5R or X7R dielectric materials, capacitance values ​​between 1-6.8μF.

Increase a feedback capacitance, and improve the stability of the output voltage, it is recommended to use a 47pF ceramic capacitor in the the MX85701 output and FB.

retail led lighting and big led display

In recent years, with the rapid development of computer technology, LSI and special components, the 256 gray-scale full-color LED display in the country has developed rapidly, but its display is not ideal: on the one hand, LED lights. The luminous efficiency of manufacturing process affect the performance of the inherent differences, but this difference also change over time, so by a large number of LED large screen display, there will be some random dark spots or bright spots, seriously affecting the display requirements, needs line point correction to eliminate this effect, on the other hand, full-color large-screen brightness levels, even with non-linear gray-scale control technology, the performance of color in low light level capability is still poor, displayed layering Another problem is caused by the lack of brightness levels is not easy to γ ​​correction so that the full-color LED display some color distortion.

TLC5941 driver chip TI’s latest point correction and the characteristics of high brightness level, he’s big screen driver program to a certain extent to solve the above problems, can constitute a high-performance display system.

retail led lighting and big led display

2 TLC5941 chip

2.1 chip features

A total of 28 pins TLC5941 is a 16-channel LED Driver can drive 16 LEDs per channel maximum drive capability of 80mA, each channel can be PWM mode depending on the value of the internal brightness register 4096 brightness control The length of each channel within the brightness register 12 In addition, the flow of each channel LED driver circuit 64 control the value of the internal 6-bit dot correction register, and the maximum drive current through the chip resistor set .

64 current control LED spot brightness correction capability, the 4096 brightness adjustment to ensure even at low brightness levels, each point in the lattice up to 256 grayscale representation, which red, green and blue The full color display 16M color color skills, these two high-quality color screen display is an additional and important.

The use of programmable logic chips (or high-speed CPU) compared to traditional color large screen display system, the design focus to generate the PWM brightness control, using the TLC5941 driver chip TLC5941 complete PWM brightness control, programmable logic chips (or high-speed CPU) only need to deal with cache management, brightness and dot correction data output, the design complexity is reduced, and PWM brightness control and data serial out of nothing to do, can easily get higher frame rates, and achieved a good dynamic display.

2.2 pin functions

The TLC5941 all internal data registers, the brightness register, dot correction register and error status information through the serial interface to access the maximum efficiency of the serial clock is 30MHz.

The TLC5941 The serial interface mode is similar to 74HC595, the interface part consists of five signal lines.

Mode (mode signal): Mode = 0 is the luminance signal input mode, Mode = 1 point correction signal input mode.

SCLK (serial clock), at each rising edge of SCLK, Mode = 0 the input data and output data into and out of the internal 192 (16 channels × 12), the brightness of serial shift register, when Mode = 1 input data into and out of the internal 96 (× 6)-point correction of the 16-channel serial shift register and output data.

SOUT: Serial data output.

SIN: Serial data input.

XLAT: data latches, the rising edge of XLAT If Mode = 0, brightness serial shift register latch to the brightness control registers, random control the brightness of the PWM output, if Mode = 1 point calibration serial shift register latches point correction control register to control the current output.

In order to safeguard the reliable operation of the large color screen, TLC5941 each way LED open-circuit and over-temperature detection, the pin XERR open collector output for alarm when an error of 16 channels, regardless of which channel the error occurred, XERR will be pulled low, query the internal state of the chip, you can know which road to failure, the system all TLC5941 XERR pin can be wired together, received a high level through the pull-up resistor by monitoring this signal, the system can self-diagnosis during operation.

In addition, the TLC5941 also provide a GCLK pin, input a clock signal synchronous PWM generation.

3 Based on the TLC5941 dynamic scan driver circuit

This design object is 640 × 480 full-color display system, where only about his driving part of the entire screen consists of four sub-screen, the size range of a sub-screen to manage 640 × 120 pixels, has a separate driver circuit indoor screen-driven design using dynamic 1/8 scan driver mode.

retrofit led lamp and led pump

In the past few years, portable devices, display and keyboard illumination feature on the demand for white LED lights driver rapid growth, this growth stems from the emergence of the color display, especially mobile phones and other handheld devices in active matrix lcd promote. Almost all power management vendors provide white light led drive, but the market is basically divided into two camps. Some people like to charge pump solutions, while others like the boost converter solutions. The reason is simple boost converter, such as higher efficiency. This article will compare the charge pump solutions with a boost converter solution specific factors, and discuss the possible existence of electromagnetic interference (emi).
Led the drive to select the boost converter or charge pump solutions for white, it is important that all the specific factors to consider two solutions. We should recognize that the final application of white LED drive requirements may vary widely, it is very important. For example, for lcd module manufacturers, component height may be the most important design parameters for the manufacturer of personal digital assistant (pda), the most important design parameters may be efficiency issues. Figure 1 shows a typical application of the White led the charge pump drive, the device used here for tps60230.

tps60230 usually powered directly by the lithium-ion battery, the typical voltage range of 3.0 ~ 4.2v, at the same time for up to 5 led power supply, each current of 20ma. Figure 2 shows the typical white led driver tps61062, this is a boost converter solution.
This is the smallest solution, the least number of external components needed. Based on Figure 1 and Figure 2 shows the solution, we will discuss the most important design parameters of the boost converter and charge pump solutions, as well as the differences between the two. However, the two designs have in common, we can also charge pump boost converter white led drive to compare.

retrofit led lamp and led pump

Comparison of efficiency – the charge pump and a boost converter

We hardly generally charge pump solution is an efficient solution, which is led forward voltage, because the overall efficiency depends on the lithium-ion battery discharge characteristics, and led current application parameters, they largely determine the charge pump mode of operation. Figure 3 shows a typical efficiency curve of the charge pump solutions. When the converter operates in the case of “the ldo mode” when a gain of 1, input voltage range from 4.2v down to 3.6v ranging from the level of efficiency higher than 75%, as shown in Figure 3. Ldo mode, charge pump, like ldo, input voltage regulator down to led forward voltage, typically 3.1 ~~ 3.5v. the ldo another mode of an active role, the device does not switch the exchange occurs, thus avoiding the emi problem.

However, the gain in the drive the ldo mode “switch to boost mode (boost mode) depending on the situation led forward voltage and drive ic internal voltage drop of 1.5, the efficiency dropped significantly. In boost mode, the device the switch occurs, the internally generated voltage rail is 1.5 times higher than the input voltage, which need to be adjusted down to the LED forward voltage levels, which reduces efficiency. Therefore, the drive to work in the time the ldo mode under the longer, the higher the efficiency charge pump.

With charge pump solutions, the boost converter tps61062 (Figure 4) are up 75% to 80% efficiency in the entire input voltage range of lithium-ion battery. Some of the boost converter solutions for its efficiency even in the case of using an external calibration diodes up to 85%, such as tps61042. If less than 5 led power supply, then the efficiency is even increased, because of the relatively low input to output voltage conversion. Overall, the efficiency of the boost converter is slightly higher than the charge pump solutions, especially when four or even more led power supply.

retrofit led lamps and new power tech

Over the years, the demand for the consumer market for mobile or portable devices and other types of electronic systems, and promote the lighting and display of power With the rapid development of and access to a wide range of applications. Lighting and power, its directory is: a single white LED lights camera xenon flash; single white LED backlight driver; OLED and TFT displays; CCFL (cold cathode fluorescent lamp) backlight; RGB LED drive and other. On the occasion of the white LED driver circuit, this article will be lighting solutions in the RGB LED drive CCFL backlight power converter, the technical features of a typical product of the photoflash charger and application of analysis introduced.

retrofit led lamps and new power tech

1,1 × / 5 × 7-channel charge pump white LED driver completely backlight solution

APS4070 is a used pump white LED driver power to pay, fully backlit, can the Secretary to support the work screen, Vice-screen and keyboard backlight driver. Serial bus interface can easily transfer complex various parts of the current, flexible drive all the LEDs. Data loaded in the register on power, shut off automatically when you save. Chip reset, the registers in the data set the LED drive current. Very low 33μA LSB current in a non-reflective LCD display allows trickle through the LED. The APS4070 door moving between 1 × and 1.5 × mode switch to high efficiency in all load range. Figure 0 (a) multi-ApsS4070 typical application circuit.

 

1.1 Main features: End a backlight solutions; divided into three groups of longitudinal independent control, respectively, including the four main LED, LED, and a keyboard LED panel; high current drive capability, four workers LED and two from the LED is 31mA Keyboard LED 60mA; built-in 6-bit DAC precision of no current; input voltage range of 2.7V to 5.5V; interface; shutdown mode, data is stored; 1 × and 1.5 × automatic switching mode; low dropout voltage and current sources. typical value of 200mV; very low LSB current 31μA; low-noise constant switching frequency; 1.8MHz switching frequency compatible with the small size of the external device; power saving mode, quiescent current of only 1μA; over-temperature protection; soft start to reduce the input inrush current; small 16-pin 3mmx3mmQFN package.

1.2 Application areas: mobile phones and smart phones, a variety of handheld devices, a variety of white LED backlight applications, digital cameras, digital cameras, handheld computers and personal media players centers on the device. Figure 0 (b) on a smart phone for the APS4070 application diagram.

 

2, a single white LED driver circuit

2.1 Technical Support

* Series / parallel LED configuration – topology Driver.

Inductive boost converter to provide the necessary high voltage for the LED tandem. Sequence, an LED tunnel lights in series and only need a current regulator and the two connection points.

The charge pump is generally used to drive parallel LEDs, each LED has a fixed current, otherwise each branch needs a current limiting resistor. This is usually determined by the pre-encapsulation of the LED in the color LED display module configuration.

rgb color changing led lights and MH lamps

High pressure sodium (HPSL) is a performance of high-intensity gas discharge lamps (HIDL led lights), its high luminous efficiency, long life, light color, so widely used. As with all gas discharge electric light, high pressure sodium lamp was negative the V-I characteristics of the ballast to suppress the lamp current, and 5 to 20kV the gas breakdown voltage necessary to start. Traditional magnetic ballast volume, low power factor (only 0.3 to 0.4), and ability to adapt to the grid voltage fluctuation is not strong, so the development of the higher cost of electronic ballasts to replace inductive ballast the general trend. Have been developed to high pressure sodium lamp electronic ballasts are high frequency electronic ballast, at high frequencies, high pressure sodium lamp is easy to put out the arc, and the existence of acoustic resonance. In order to avoid acoustic resonance, have been developed to high-frequency electronic ballasts for 600W high pressure sodium lamp with a frequency modulation technique, the current operating frequency of the high-pressure sodium lamp moment around the center frequency up and down changes. Start part of the LC series resonant circuit generates a high voltage, simple and reliable.

An overall control strategy

rgb color changing led lights and MH lamps

The circuit block diagram shown in Figure 1. The main circuit is divided into two, the first level for the rectifier and active power factor correction circuit (APFC), the second stage inverter circuit. It can be seen, the electronic ballast is essentially a typical AC / DC / AC conversion circuit. Auxiliary power by the UC3844 single-ended flyback power structure, the output voltage of 18V to the chip supply.

 

Overall structure of the map in Figure 1 600W electronic ballasts

Two rectifier and APFC part

Alternating current through the diode rectifier input voltage is sinusoidal, but the input current distortion, inefficient, large-scale use will cause serious harm to grid, while the input current harmonics generated noise will also affect the circuit operation. The APFC enable circuit input power factor to 0.95, so that the input current of the basic sine wave, harmonic content is greatly reduced. In this paper, FAN7527B control Boost Circuit as the APFC circuit shown in Figure 2. FAN7527B Fairchild Semiconductor’s production is simple and efficient power factor correction, contains a R / C filter, so the external circuit does not need to access the R / C filter. Transformer T1 secondary has two roles: as a current zero detection signal to the chip power supply at the same time. This chip uses the voltage and current double closed loop control, and the inner use of discontinuous current uncertain frequency mode control. Voltage detection signal  and synchronous signal multiplied by the given as a current, R5 is the current sense resistor. The output voltage can be controlled in a wide range According to the latter, a need here to control 400V.

Three high-frequency half-bridge inverter part

High frequency inverter is an important part of the high pressure sodium lamp electronic ballasts, the half-bridge inverter variant form, the less the two capacitors, a simple structure, and cost savings. Circuit output voltage is half of the full-bridge, in the same output power conditions, the half-bridge power tube current than the full-bridge twice, taking into account the normal operating voltage of the high pressure sodium lamp, half-bridge circuit to fully meet their needs. Shown in Figure 3, the course of their work for the inductor L1 and C9 the first of the series resonant frequency of 200kHz, 7kV high pressure, high pressure sodium lamp ignition, after ignition, high pressure sodium conduction, C9 does not work, due to C8, >> C9, C8 and inductors are not resonant, played the role of the ballast, then the fluctuations of the frequency to 35kHz to 2kHz range, high pressure sodium to the normal operation of the constant power for 1 min. Half-bridge output square wave, C8 and L1 ballast into high frequency alternating current.

rgb color led in old buildings

For landscape lighting design, ancient buildings are non-renewable, reliable protection under the premise of modern lighting design and implementation. The lighting design must comply with the following principles:
1, protection and utilization principles. Ancient architectural lighting to achieve elegance to showcase its ancient buildings, reflecting the cultural and artistic connotation, and can not damage the ancient buildings, to protect and use the dual demands of the ancient buildings.
2, does not change the principle of the status quo ante of the ancient buildings. Such as more than 800 years of ancient buildings is prohibited electrical wiring.
3, according to the standard design principles. Illumination or brightness of the lighting, the light source of infrared and ultraviolet content, exposure time and light color parameters need to be in strict accordance with the standards for the design.
4, the strict management principles. Lighting Design, we must consider the lighting facilities maintenance and management methods and measures.
Before due to the limitations of the luminous efficiency and light, the lighting of ancient buildings there are a range of issues, such as:
installation of lighting fixtures. Large-volume lighting device directly fixed on the building above, not only destroyed the building structure and its daytime landscape. And no way to show the beauty of ancient buildings delicate lighting changes.

rgb color led in old buildings
b, lighting method. Long-range projection for the protection of buildings, but most of the cast light shade measures, resulting in overflow of light more to the outside of the illuminated objects, the initial estimate about 1/4 to 1/3 of the light from dissipating into the air and outside the illuminated object
, The formation of light pollution. The neglect of energy-efficient major premise.
c, the choice of lighting fixtures. Lack of
Consideration of the lighting fixtures as ultraviolet and infrared radiation, causing irreparable damage to the ancient buildings.
In ancient architectural lighting, LED display unparalleled advantages.
Accumulation of large heat safe lighting system: LED lights source power of all low-voltage drive to solve the heat dissipation problem is not easy to satisfy the requirements of fire safety.
Green lighting products: infrared and ultraviolet light, will not vandalism, while the light source does not contain mercury, will not cause environmental pollution, is a truly green lighting products. Give full play to the compact design with point lighting, surface lighting, partial lighting suitable for display in the art lighting design space is very large. Long life, up to tens of thousands of hours, low maintenance costs.
Instance – Xiangunan door walls
Overview:
Inside and outside the Xi’an ancient city wall preserved intact, the vigorous development of tourism resources, the formation of the human heritage features in East and West, North and South 24 radiation. Xi’an city wall in the Sui and Tang dynasties, “Imperial” on the site of the Ming emperor Hongwu years after eight years of expansion from our existing largest and best preserved ancient city building.

 

Xi’an city wall of Ming Dynasty Hongwu to the 6th century when the Sui and Tang imperial walls based on expansion of the formation. The ancient city wall every 120 meters there is a 12m * 20m salient known as the “enemy” Every enemy on stage has troops in fortresses one. City Siyu built turret one. East, west, south, Beiyuan the construction of the Shing Mun a, respectively, for the East the Changle door, West Andingmenwai, South Yongning door, Beian far from the door.
Outside the city were built to protect the door Urn Urn on a built tower, watchtower each one. Urn outside the inside of the moat shore Pro, has a gate control “suspension bridge” floor, an, Confucius Temple flanking City top built Kuixinglou to a surface of the top of the walls to three-brick Fuman puzzle, known as “sea TRANSACTIONS. The outer edge of the sea Fuman build crib wall and the whole city the total Duokou 5984, along the contact of the “parapet”.
This article describes the LED lighting is the south gate of landscape lighting, including the tower, gateway buildings, watchtowers, Kuixinglou and walls battlements and drainage holes. Walls on top of the building landscape lighting design:
The south gate of the ancient city wall buildings, including towers, gates, buildings and enemy units on both sides of that part of building the overall performance of the ancient Chinese architectural culture is the iconic buildings of the south gate of ancient city wall, the general features of the Department of the Qin and Han style of multi-level tower construction, brick and gray tiles, carved pillars and painted beams, although the age-old, but still kept a full roof cornices momentum imposing atmosphere.

The fifth development trends of the led lighting design industry

Take the Bird’s Nest as an example, in the initial program, the color of the design center around how to maximize use of the building itself to create the visual effects. The designers hope that the complex structure of abstract led lighting design and the Bird’s Nest sparks will build to become the world’s largest art.

led lighting design

But the function of the stadium, security of public buildings and energy-efficient cast a negative vote. Similar to the use of construction outside of the body as a carrier, the use of digital systems to do color projection, that will be building itself into a luminous body, installation of lighting equipment such costs, equipment, energy consumption and conservation is difficult, led lights pollution, heavy programs have all been cut.

In the final program, the Bird’s Nest internal functional areas and the outer wall using most conventional illuminated red light projected; illuminate the facade and left sides of the U-shaped surface with white light projection; steel between the roof of the upper and lower membrane structure and also illuminated with white light projection. Both the form and function from the inside out, nationalization of world-class architectural styles. It is very exciting.

The construction of light environment on the building is essential. No suitable light, architecture can not better perform its functions, affecting people’s work efficiency and mood. A lot of artistic effects can not be demonstrated. Light and vision is directly related to the lighting environment is also related to the performance of the indoor space and architecture modeling.

Trend: To promote the “Lighting of Economics”

In fact, the led lighting design is a management, the Yuan Zongnan to the majority of designers to make this comment:

Designers need to know the rational led lighting design, control the lighting changes in the flow of more and less hours, minutes. More could be considered light, the light concentrated in this period between seven to eight people. With the reduction of the flow of  people, the lights can be reduced to 30% or 20%.    It can not only save energy, protect the quality of sleeping, but also shows the transformation of beauty.

The fourth development trends of the led lighting design industry

Trend: City landmark humane care of the lighting

For the chief designer of contemporary cities, they have to build a landmark building, to create the boom of the city’s calling card, said by Zhimei who participate in and presided over too much landmark led lighting design.

Skyscrapers can not be advertised as a city flag just because of its scale, architectural features. It need remarkable and symbolic meanings design. Lighting, instead of telling the exclusive story of the building, convey the humane care of the city.

led lighting design

So, how to enlighten the iconic building?

Throughout the night view of the country’s premier landmark design effect, the chief designer of Zhimei to see that the CCTV new site building is a good case: its grotesque irregular shape for architectural lighting, lighting installation has brought a lot of fresh challenges. In the use of the advantages of its own structure, get rid of some dead ends, designers lit up with daytime look, showing the school of simplicity, gentle, elegant, subtle solemn beauty, not only heal lead to one put into use before boos, including but not exposed is designed to also happens to coincide with the building image.

An increasing number of landmark building, due to the careful design of the lighting project, which is more attractive. In future led lighting design, the designer is not thinking about the projected intensity of the light projection of the way and let the light guide, carve out the unique charm of the building, allowed freedom in the urban night sky flying humane feelings.

Trend: Light design need to remember function first

Lighting objects vary widely,  different buildings require different lighting styles, different functions require appropriate lighting assistant to achieve. Gorgeous atmosphere of the Bird’s Nest Stadium, the Shanghai World Expo modern Famen stupa solemn and dignified, colorful Guangzhou waistline … whether LED lights or traditional fixtures, how to use and choose, the only criterion is the function first.

Year-round to reach the major domestic and international engineering, the chief designer of the Zhimei see well aware of how to find the optimal balance of customer demand and the actual operation. The function of art, the persistence of functional he is committed to the pursuit of the effect.

rgb led color and car light

LED For the consumer, has been widely used in the car, depending on the performance requirements to select the appropriate LED products, LED compared to traditional light sources in addition to the appearance different, the performance output and optical output is also not the same optical design and thermal design is different from the traditional lighting of the design concept is applied to the headlamp will face. However, because of its different from the characteristics of traditional light sources, and to successfully integrate with the body to overcome the technical problems for the models to create a new design concept.

LED has been widely used in interior lighting or instructions with light, we can see from Figure 1, from the dashboard of the car lights, car dome light, make-up lights, welcome light to the vehicle’s tail lights, front and rear turn signals. down lights, third brake lights, and other related applications can see the LED.

rgb led color and car light

From the historical point of view of LED applications, as early as 1992 when the LED used in the precedent for the third brake light; 2000 is further applied to taillights, turn signals and brake lights; take the lead in the 2002 Audi A8 LED light source placed in front lamps as daytime running lights, turn on the imagination of designers and engineers in the front lamps. Can be seen on the many international auto show concept car, the LED lights as a headlight source.

rgb led color and car light

LED inherent small size advantage, applied to the front lamps may reduce the volume of the entire group of lamps, and further to give up valuable space for engines and other related equipment existing halogen bulb or discharge lamp design lamps with a total length 300mm, in concept car design, LED lighting is only 125mm long. By the advantages of small size, with the design of a variety of different design, and then for the body shape to create a different visual perception, escape from the circular design of the traditional lamp.

Different as the application level, the depot also use the LED light source package corresponding to the different environmental requirements, according to the different needs of brightness can be simply divided into two directions with lighting and projection in three different Indication light source visible in the third brake light, rear light clusters (taillights, brake lights, turn signals, etc.), side lights, low lumens light output, low power required of about 70mW ~ 200mW, the heat generated package less affected body, so the package will ignore the impact of this heat, and direct use of the resin material coated to the package as a whole, the resin with low thermal conductivity (W / mK), so its thermal resistance heat is not easy to rise to 50 ~ 200K / W; illumination light source package power relative to the higher brightness of the daytime running lights, fog lights, can be applied to the directions of the light source used class of products, can also be used, before the direction of light, but also because of the loss of power increase (power about 1 ~ 5W), the thermal part can not, as indication light does not consider heat issues still need to use a piece of metal will heat export, in addition to the resin material package in order to maintain the optical efficiency , maintained at below 15K / W thermal resistance; and projection light source, light package brightness needs, the main lighting system (far lights, low beam, fog lights, etc.) before their application, and its single package required 4W or more, while less than 5K / W thermal resistance on the need to ensure that the cooling capacity to maintain the high temperatures of the engine room, and maintain the efficiency of the light output in the range of available

Different level, the total brightness needs about 80 lumens of brightness to the interior lighting is generally used in surface mount (SMT) package, single package about 2 lumens of output, efficiency up to 15 ~~ 20lm / W. About 30lm the brightness of the third brake light, is generally used in the artillery-type package structure (φ = 5mm), the brightness of the single package about 4 lumens, the efficiency of up to 20 ~~ 40lm / W.