 Wysłany: Pon 3:31, 28 Mar 2011 Temat postu: LED can also improve the product of the spot resul |
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| LED forward current with temperature and working time change, but the deviation of each LED are not large, for the link up with multiple components of high-power LED LED lights, and will not the life of the LED and the color have any effect. Secondly, the use of closed-loop control,illuminated signage, can achieve a high output current accuracy. Can guarantee the consistency of light. Again, the power of compatibility issues. MCU-compatible constant current control scheme below rated power LED lights.
For the series of LED lights, change the size of the output power, but only changed the number of LED lights to LED lights n and output voltage, output current does not change the size. When the output power than the rated power hour, plus the LED lights on the clamping voltage, the output voltage to the LED is rated at this time still, so the current flowing through the LED will become large, making the current feedback signal is greater than the baseline voltage, the duty cycle becomes smaller,display boards, the output voltage, current flows through the LED's are small, until the rated current value. Rated power so it can be compatible with the following LED lights. The problem for the no-load losses can be used to detect whether a load access MCU, LED access when not detected, you can turn off the circuit after the class BUCK, reducing the load loss. Finally,LED open sign, the SCR compatibility issues. Constant power control scheme, using pure hardware mode to stabilize the SCR turns on, the adaptability of dimmer or limited. Constant current control in the MCU program, in addition to stable hardware circuit,LED display board, as well as software to SCR chopper waveform after the identification processing. Can be set by software to determine the waveform after the chopper is really distortion or dimming, and to determine whether or not to alter the dimming signal. |
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