Need some help with dimming circuit

[KRavEN]

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

[rimai]

May work, but I wouldn't connect emitter directly to +12. I'd add a 10K resistor in between or you may short out +12 and GND and it starts flowing current.

[KRavEN]

Okay, from more research these look like another re-branding of the reefbreeders 120 value or evergrow 120 fixtures but the drivers look updated from what I've been able to find. I found a reefcentral thread where they show drivers very close to the ones I have further down in the thread but doesn't look like they did anything with the unused ports I'm trying to use, just the DIM1 and DIM2 pins. http://www.reefcentral.com/forums/showt ... ?t=2306251