Get a 1/3HP electric motor that plugs into the wall. It runs on 20 amps an spins at 1725 RPM. Then I attach a 200amp automotive alternator to it. I run wires from the alternator to an inverter and I can run my whole house on it. right?
Yes but not very well.
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1) 20 amps at 110 volts is 2200 watts. This is about 3 hp not 1/3 hp
2) 200 amps at 12v is 2400 watts. More than 3 hp. Alternators cannot put out max all the time either, the windings will burn up.
Ain't gonna happen.
You also have the efficiency losses in the motor, alternator, belt? and inverter.
Maybe 1500 watts max after all that.
You'll lose close to a hp in wasted heat.... no point other than just to see if you could do it.
Nice cheap way to build charger for a large amperage 12v battery pack though if you don't want the expense of a regular high output charger. I would use a 220 volt motor though at that wattage.
Lee B
www.packratworkshop.com
I didn't think it would or someone would have already done it. Would it make a difference if you ran say 4 alternators off the motor?
You will get even less because each alt has it's own inefficiencies plus the loss from what ever you use to drive them. You are not going to get more out than you put in with this type of setup. Like I said before it's a good way to make a cheap battery charger but that's about it.
Lee
www.packratworkshop.com
reread everything 'bout rotovrter
that way it might work (if your motor is suitable for rotoverter type oil condenser connection)
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wiz