Originally Posted by Jackso
To get real numbers, wattage is a function of voltage and current. W = V * I Therefore, if you're talking 160 A at a 12 V system you're talking 1920 Watts. Just because the amp says that it produces 1500 Watts of audio does NOT mean that it draws 1500 Watts. Amps are lossy. Now, to get technical, you're system will produce on average 13.6 volts. Thus the amp is REALLY using 2176 Watts when it is produicing 1500, which is about right. 70% to 80% efficiency is about what you'll expect.

In any event, if you wish to run EVERYTHING off of a single fuse/breaker, you're looking at needing about a 260A breaker. But, you are then still back to needing to fuse each individual item. This is because your 250W pc power supply isn't going to blow the 260A breaker before the wires become the fuse and catch fire. I stand by my suggestion to get a Fuse distrobution panel.

jackson... I didn't mean you dude. i meant that other guy talkin about 40 watts per channel. Heheh ~ that example was for his "fuzzy" math.

But no again. You're math is all good on paper, but you have no idea what class circuitry I am running, or what amp alt's I am mounting. None of my amps draw wattage... instead, amperes that they convert to wattage. And no, there is no constant 13.6 volts because the regulators on the alt's are reg'ed @ 12v+ ... 80% efficiency AHAHhahhahah I wish. Also, the measurements of what you call "real" assume that I am using an unregulated power supply on my amps. Not the case; they are regulated and rated to produce @12v. The bridge woudln't even see a .2 spike in voltage due to reg.

You are on the right track about efficiency tho. Some amps are definately not as efficient as they say. Hence some amps would have a much higher rating for its fuses which protect the circuitry Remember this, no matter if it's a toaster or a 5kilowatt lanyard, they all suck amps. Amp ratings are always device specific. thanks for help