LED is a kind of display device with excellent performance. It has the advantages of long life, power saving, high brightness, multiple illuminating colors, fast response speed and low driving voltage. It can also adjust the LED luminous intensity through PWM device while saving energy. According to the R, G, B three primary color mixing principle to call out a variety of colors, and then through the MCU intelligent control to achieve a variety of display effects. It is now widely used in urban lighting, architectural landscape lighting, stage lighting design and other fields.
This design uses NXP Semiconductors (NXP) power management chip, a microcontroller, I2C devices, LED driver member, a full range of design for the LED lighting system design.
Main chip: PCA9633/34/35: NXP I2 bus RGB/RGBA LED flashing/mixing chip; TEA152x: NXP power chip; LPC92x: NXP 900 series MCU; P82B96/PCA9600: NXP I2C bus driver chip.
main application:
1. Point light source: Apply LED color screen display principle, enlarge its pixels, reduce the overall cost of production, each module is a color pixel. Application environment: bars, KTV, stage, shopping malls, exhibition halls, as music melody display, background wall decoration, curtain wall advertising, etc.
2. LED rainbow tube: Each tube consists of multiple color pixels (RGB), each of which can produce 256 gray level changes. Application environment: decorative lighting in different places such as overpasses, river guardrails, and building exterior walls.
System hardware design:
LED color light control system mainly includes three parts: drive module, control module and LED power supply.
Drive module design
How to realize the LED module to present different colors, mainly relying on the human visual intermittent inertia principle, using the duty ratio of the LEDs of the three primary colors R, G, B to achieve color mixing. The LED color display of this design mainly relies on NXP's I2C interface LED flashing/mixing driver chip PCA9633 (PCA9633-4 bit PWM output, PCA9634-8 bit PWM output, PCA9635-16 bit PWM output) output 256 gray level Color to achieve color display. The controller only needs to transmit the gray value of the RGB color of the module to realize the color display.
PCA9633 is a four-bit LED driver device with programmable PWM output controlled by I2C bus. It is mainly used in LEDRGB/RGBA (Red/Green/Blue/Amber) mixed light. The main performance indicators are as follows:
1. 4 channels of LED driver, each driver can be programmed into four states by software: open, off, programmable PWM flashing control output, programmable gray level per channel, and support for four-way overall brightness adjustment PWM Mixed light output.
2. Dimming control, PWM output frequency is 97kHz, each channel has 256 gray levels.
3. Flicker control, PWM programmable frequency range 24Hz~10.73s, duty cycle programmable range 0%~99.6%.
4. The overall brightness of the four PWM outputs can be adjusted by 256 levels through the 190Hz PWM output.
5. The four-bit output can be programmed to push-pull output (25mA sinking current, 10mA sinking current at 5V).
6. 7 hardware address setting pins, the maximum I2C bus can be connected to 126 pieces.
7. Each PCA9633 has four programmable software addresses: one full response address and three subaddresses.
8. Built-in 25MHz crystal oscillator and power-on reset circuit, software reset can also be realized through I2C bus.
9. SDA/SCL built-in noise filter supports 1MHz I2C fast mode.
10. Support hot plug, low standby current, support voltage range: 2.3~5.5V.
The following figure shows the design of the drive unit. The number of red, green and blue 3-color LEDs can be multiple. According to your own design requirements, you can select the parallel or series connection, and then select the suitable according to the LED connection method and voltage/current requirements. The switch tube can be used, a small number of LEDs can also be directly driven by PCA9633, the specific parameters can be found in PCA9633. The driver module sets the access address through the A6~A0 pin of PCA9633, and can work normally on the I2C bus outputted by the control module. Each I2C bus can connect 126 dimming driver modules.
Lithium batteries are primary batteries that have lithium as an anode,mainly including lithium-metal batteries,lithium-ion batteries and li-polymer batteries.however,the lithium-ion batteries and li-polymer batteries which have widespread application in every field of life has solved many problems for human beings ,firstly,as commonly used lithium battery ,li-ion battery has some advantage as :
1.The energy ratio is higher. With high storage energy density, it has reached 460-600wh /kg, about 6-7 times that of lead-acid batteries.
2.The working life is longer, it can reach more than 6 years, and the battery with lithium ferrous phosphate as the positive electrode and charged with 1C DOD has a record of using it 10,000 times.
Secondly ,the advantage for li-polymer batteries as :
1.No battery leakage problem, the battery does not contain liquid electrolyte since it uses colloidal solid
2.The battery can be designed in many shapes
3.It will have twice the capacity of a lithium-ion battery of the same size
Lithium Battery,Lithium Battery Pack,Rechargeable Polymer Lithium Battery,Lithium Ion Battery 12V
YFJ TECHNOLOGY (HK) CO.,LIMITED , http://www.yfjpower.com