You actually need to put the transistors on the *low* side of the LEDs.
Feed the signal that would have gone to the led on the board into the base of a tip3055 transistor ( 9 transistors ) one to replace each led. Connect the +12 V input on each LED block to 12 V. Connect the "ground" connection on each LED block to the collector of the transistors. Connect the emitter of each transistor to ground (common).
And, this assumes that the LED modules are simple, with nothing other than LEDs (and possibly resistors) inside. If there are other components-- including capacitors or active electronics --this may not work at all.
Windell H. Oskay
drwho(at)evilmadscientist.com
http://www.evilmadscientist.com/
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Evil Scientist
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Registered: 06/15/06 Posts: 1932
Sunnyvale, CA
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