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samnwck
February 10th, 2011, 07:03 PM
Been trying to figure this out and kinda feel dumb for asking buttt... I've been trying my hand at making a circuit, I'm good at wiring but never had to design a circuit so it's all new to me. I've got 15v 369ma(Milliamp) source and I want that to go through a 12v 20a switch. Now what I'm trying to figure out is whether or not this will burn out the switch or is the 12v 20a a different way of saying do not exceed 240 watts in which case I'd be fine seeing as how I'd be taking up roughly ~5.5 watts... I honestly tried looking it up and asking around in a couple different forums but no one replied and this was a last resort to come to a modding forum, but you all seem like smart chaps (been hovering around this community for 5-6 years) so I figured you might be able to help me out. I know this probably isn't the place for this but thanks if anyone can provide some help :D

jcap
February 10th, 2011, 10:40 PM
Well, the power rating on the source is basically the maximum it can output without overloading. In your case, it can provide a constant 15V at a current between 1 and 369mA. If you have a 12V 20A switch, unless you are using a transistor to switch, you shouldn't have any problem with a SPST or SPST switch or something similar.

samnwck
February 10th, 2011, 11:10 PM
Thanks so much for the insight. So the voltage really won't matter too much on the switch? And will it let the full 15 volts through or will it just stop it at 12? My gut tells me that it should let the full 15 through because I've seen people mess up putting the wrong switch plenty of times and it just burns out faster, but that was only with incorrect amperages...

jcap
February 11th, 2011, 10:12 AM
A switch isn't a voltage limiter. It's merely two metal contacts. If you've seen switches burn out before, it's because they were running so much current through it that it basically burned out like a fuse. But if you are using a 12V switch with only 15V and 300mA, you have nothing to worry about.

=sw=warlord
February 11th, 2011, 12:09 PM
The switch would have more issue with the current that voltage, the current is what causes the damage and not the voltage.
It will handle the voltage perfectly fine at that current.

samnwck
February 11th, 2011, 03:02 PM
Precisely what I was thinking. Thanks for the clarification fellas :D.