Voltage generated by an LED light??

[dwh]

Probably just glommed the board from some existing unit and hacked it to work in the new unit.

 

[rayra]

Yes, likely. Or the LEDs available had more output / draw than the circuit plan anticipated and they cranked the boards out and **** didn't light up.

 

[Rando]

If we are to engage in some wild speculation, we should at least have some grounding in physics. Capacitors don't "throttle", "step up" or "boost" a circuit. Capacitors temporarily store a charge, and to take a simplified view - they act like an open circuit to a DC voltage and a short to circuit to an AC voltage. While none of us know the details of this LED driver circuit - a couple of things stand out - each set of 3 LEDs has a driver circuit (the ICs with the inductors look like constant current drivers). For high power LEDS you don't just put them in series with a resistor to limit the current, you drive them at a specified current, independent of the supplied voltage and the other LEDs in the circuit.

As for the electrolytic capacitor in this circuit - it is not part of the LED driver (there appears to only be one, not one for each LED) and it appears to be across the incoming power line (it looks to be across a TVS protection diode, not a resistor). My guess is that it's purpose is to filter transients on the power supply - the LED drivers are switch mode devices and the cap is an attempt to prevent noise from the switch mode drivers leaking out of the lights and producing electrical noise on the vehicles 12V power. No big deal if this capacitor dies or is disconnected - maybe just a slight increase in 12v noise. Of course this is all just speculation .