Need some help with dimming circuit
Posted: Mon Aug 26, 2013 12:16 pm
I picked up a no-name chinese light fixture in trade at a frag swap this weekend. It uses AC dimmable drivers that are controlled via 2 trim pots. I opened it up because that's just what I do and it has 6 AC input drivers with 3 drivers on each trim pot. I pulled off one of the drivers and the orange case says "Shenzen CT Lighting CO, LTD" but no model number anywhere. The only thing that looks like a model number on the driver PCB inside is LT-PCB-1056D but I've been unable to find anything on that. It uses a BD9673 IC for voltage and output control. It also has 12v DC out header for a cooling fan
It looks like it has 2 dimming options. The ones that are hooked to the trim pot are on a 2 pin header and labeled DIM1 and DIM2. The only other header on the board that was unused has 3 pins labeled +12V-D, VDIM+, and D-GND. I'm hoping these are for PWM dimming.
To test I was thinking to just hook up a 2N2222 transistor. Base and 1k resistor to a pwm pin on my arduino. Collector to VDIM+. Emitter to +12v-D. D-GND to arduino ground. Anyone have any other ideas or suggestions?
Here are some pics. https://copy.com/GXSIkAd1hHww
It looks like it has 2 dimming options. The ones that are hooked to the trim pot are on a 2 pin header and labeled DIM1 and DIM2. The only other header on the board that was unused has 3 pins labeled +12V-D, VDIM+, and D-GND. I'm hoping these are for PWM dimming.
To test I was thinking to just hook up a 2N2222 transistor. Base and 1k resistor to a pwm pin on my arduino. Collector to VDIM+. Emitter to +12v-D. D-GND to arduino ground. Anyone have any other ideas or suggestions?
Here are some pics. https://copy.com/GXSIkAd1hHww