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How to convert a 12V LED string designed for use with an AC/DC power converter for direct wire to a 12V DC system? Answered

I am trying to use a 12V LED light string for lighting in a bus conversion.  The LED string is 12V, but comes with a AC/DC adaptor so it is intended to be plugged in to an AC outlet...however, I want to connect it directly to the bus/RV's 12V DC electrical system.  I'd planned to just use a DC connector to replace the power adaptor and connect directly to the 12V circuit/wiring...but I think I need to regulate the amperage going in to the LED string. ??  I am not sure what to use to regulate the current of that circuit.  I've read about LED drivers, but most seem to be AC/DC...and I want DC/DC.  Also, the constant current drivers don't seem to match up to the current the light string would require if I assume the power adaptor is supplying the correct amperage.  Help?

The LED light string does not state many specs, except that it is 12V / 6W and uses 100 micro/fairy LEDs.  The AC/DC power adaptor that comes with it says the output is 12V/1A, therefore I assume I need to regulate the amperage to 1A...but wanted to confirm with someone more knowledgeable than me.  The RV electrical system is composed of a 440AH battery bank and from what I've read about LED's I can't just wire it into a circuit fed by that much potential current, even if it's fuse protected at the DC distribution panel.  Any suggestions?



1 year ago

I have a bunch of these strings, they are pretty tolerant to voltage variances.

First thing to note is that it doesn't matter what the amps are, the string will only use what it needs. Think of it like a light bulb. you can screw a 60 watt light bulb into a socket that can provide 500 watts but the bulb will still only use 60 watts. Its the voltage that can cause problems. If you need another illustration compare it to water. Volts is the equivalent of water pressure, Amperes is the equivalent to the diameter of the pipe, 1/2 inch, 2 inch whatever. If you have little water pressure when you turn the facet on you will only get a little water no matter how big the pipe is.

Car voltages can and will vary from under 12 volts to as high as 16 or 18 volts depending on the battery, alternator and if the engine is running. The strings should handle it but high voltages will shorten its lifespan. They will be brighter when the voltage is higher but they will burn out faster.

If you are really worried about it you can get a cheap little voltage regulator, otherwise just wire then to the 12 volts of the bus.

Looks quite nasty quality wise but should not require any regulation.
If you feel the need for different light levels you can get a cheap LED dimmer for LED strips on Ebay and put it between power and your strip, some even come with a remote control these days.

I don't think this needs a constant current source. Just plug it into 12V