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Old 01-25-2008, 08:17 PM   #10 (permalink)
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Originally Posted by WaxyChicken View Post
BTW, you said a 12v battery. Car battery will work, yes? i think the one in my car has 750 cranking amps. i can jumper it to the battery for a test. (don't wanna fry it on amps.- i know even less about electricity.)
When matching supplies to components consuming electricity you need to be concerned with a couple things that cause problems. For motors specifically you want the voltage UNDER LOAD of the supply, the battery here to be equal to or lesser than the rating. You can overdrive motors but not forever. It's very safe to do it repeatedly if its short, and you won't harm anything. Anyways, when you supply any voltage to a motor, the motor will "demand" amps based on the load, if the battery cannot supply it, it will just supply as much as it can and the motor will make do with what it gets. Likewise, if you can supply 4x the amps of what the motor is rated for, that's perfectly fine, for the most part. You have a controller that will help you there in the actual car anyways.

With other electronics, you always need to match voltage under load to the rated voltage. For circuitry it is generally important that you have a source that can supply the rated amps or MORE. Just because a power supply can carry 5 A doesn't mean it will send 5 A - it will only send what the circuit desires.
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