Reply to "Another LED constant lighting question for passenger cars . . ."

gunrunnerjohnOGR Forum Member SUPPORTING MEMBERDIGITAL SUBSCRIBER

I go with 35V capacitors, they've always been sufficient. The voltages on 18 volts end up being in the 26 volt range on the capacitor. 25V capacitors would probably fail pretty quickly with that voltage. The circuit above is good for around 50ma without any heatsink, if you're driving 12V lighting strips with an 18V AC power supply, that results in .8 watts power dissipation in the LM317. It'll get around 70C or so, but within it's operating ratings. If you want more current, add a heatsink to the TO220 regulator package.

1/28/173:27 PM

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