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Weatherman49
Member
Username: Weatherman49

Post Number: 52
Registered: 2-2005


Posted on Thursday, August 23, 2007 - 11:38 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey guys gonna throw out an idea I had an would like your feedback It just so happens I have a 100 amp alt from a nissan and a 120v electric motor sitting around doing nothin so I decided to use them somehow> here is my Idea> mount the alt and drive it with the motor this alt puts out 100 amp at 13.5 to 14v which should be plenty for my radios now comes the part of filtering I don't want to use a big battery because of the fact I dont want it in my house the alt and motor are going to be under the house directly below my radio whith heavy gauge wire comming up to the radio to keep the noise from them as little as possible. the haevy gauge wire will be mounted to a fuse pannel for splitting it off for different stuff radio amp ect. my main question is filtering the thing to reduce the hum. What Caps would be a good choice to use I have some pretty large ones that came out of an old tv (Pack rat I know) these i believe would do the trick but somebody with a little more knowledge may tell me something I havent thought of thanx in advace

Weatherman
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Tech291
Moderator
Username: Tech291

Post Number: 478
Registered: 11-2004
Posted on Thursday, August 23, 2007 - 8:57 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

James,
To make full rated power,an auto alternator needs to turn nearly 3600 rpm.most ac motors turn at 1725 rpm.a 2:1 ratio on your drive pullys will solve that(6"on motor-3"on alt).now the biggest problem arises.that 100 amp alt will need at least 7 bhp to make full power.with a 2:1 drive you have to double the motor hp,>14 horses!electric motors of that size are 3 phase so that means you wont run it at home.
Old military surplus stuff used that principal for their power supplies(search dynamotors)but they used a high amperage,lo voltage to create a hi voltage-lo amperage supply.

tech291
cef291/cvc6
kc8zpj
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Weatherman49
Member
Username: Weatherman49

Post Number: 56
Registered: 2-2005


Posted on Friday, August 24, 2007 - 11:35 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

thanx 291 did not take into account about the ratios and the rpm needed for full power
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Allagator
Advanced Member
Username: Allagator

Post Number: 769
Registered: 9-2002


Posted on Friday, September 28, 2007 - 6:57 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey Weatherman ive got a setup you would love to hate ! LOL 8 horse briggs running a 90 amp alt and it works fine with my radios when the power is off but i cant run my amps without getting a strange noise ! HUMMMMMMMMMMMMMM but im still working on that part ! LOL
hope it helps !!!!!

Allagator
CEF 115

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