Mini and Micro Generators


From: Greg Weinfurtner (
Date: Tue Jul 11 1995 - 11:57:53 EDT

Good afternoon to all,
        Has anyone tried or came up with a mini generator to recharge
batteries or even run a rig during field operating? I have a 5KW generator
(120vac) at home, but, geesh, that is overkill! Plus, at around 100lbs+,
it is no fun to haul around!

       Here's what I'm working on as a mini-generator... I rewound a Delco
alternator (basic 60A @12VDC) for single phase power by cutting out every
third pole on the stationary armature and winding the new coils over 2 of
the poles of the stationary armature. (This alternator is normally a , 3
phase, revolving , field (7 pole pairs) type.) I wound it with #16 wire
and can get about 650 watts out at 120vac @ 3000rpm. Field power
requirements are about 17 volts dc at 2.5 amps or so. There is a tap on
the armature at 24 volts for powering the field.
       The frequency is a few hundred cycles and will power lights, TS-520
and a battery charger. It will not run a typical fan, clock, refridge,
       I built a solid state regulator that controls the field voltage by
sampling the output voltage, although the regulation is not too bad without
it. An open circuit voltage of 140 vac drops to 118vac under a 500 watt
load. So, running the TS-520 at 130 vac only drops to 120 vac at full
power output.
        Add a 3 hp gasoline engine and it wouldn't weigh too much to carry
around, but still a lil on the heavy side.

        Micro generator-I was thinking of something on the order of a
weed-eater engine driving a small alternator or DC motor as a generator. I
think these lil engines are around a horsepower or less... should be able
to get a few hundred watts out of it...13,8 volts at 10 amps? That could
really charge a marine battery in a hurry and would be light-weight to
carry around. I haven't experimented with this yet.
        Anyone out here in cyberspace doing anything along these lines? If
so drop me a line and maybe we could exchange some ideas.
        (It's funny...I enjoy working with electronic circuitry, but there
is just something fascinating about electrical rotating machinary...)

73! de

* Greg Weinfurtner AEE BSS *
* NN N SSSSSSS 8888888 OOOOOOO Electronic Design Splst *
* N N N S 8 8 O O Ohio University Athens *
* N N N S 8 8 O O *
* N NN SSSSSSS 8888888 OOOOOOO "Can thou send forth lightings *
* that they may go and say unto *
* Amateur Radio thee, 'Here we are'?" Job 35:38 *

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