[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 3 phase car alternators



Original poster: Tim S <stm800@xxxxxxxxxxx>

when you modulated the field winding did you remove the guts from the thing that holds the slip ring brush contacts to the field winding?

there are active electronics resistor/shunts/and a voltage regulator in there.
 i removed the guts and wired the brushes straight out the side hole.

i think i might have some time this weekend to try it out a bit.

can someone give me some ideas on how i should plot some data?

i have mine hooked up direct drive to an old wood router.
the router will run directly from a dc voltage and the last time i remember 12 vdc on the router gave it 20,000 rpm with no load attached. i will dust off my hand held tach for router rpm and scope with frequency counter for the output of the alternator.

i will at least start the idea back up for i allready have the stuff collecting dust and taking up room..if it don't work out to the trsh it goes..

tim



Tesla list <tesla@xxxxxxxxxx> wrote:
Original poster: "S&JY"

I tried your idea below many years ago. I modulated the field winding and
left the rest of the alternator as-is. The idea was to modulate the field
winding at 60 Hz to cause the D.C. output to be modulated also at 60 Hz.
Sort of like a magnetic amplifier. Unfortunately, at least for the
alternator I tried it with, the "frequency response" rolled off drastically
at only about 10 Hz, and at 60 Hz there was no useful AC output. Very
disappointing. But maybe you have a different style alternator that can
function well with a 60 HZ field excitation. Please let us know how it
works for you.

--Steve Y.

----- Original Message -----
From: "Tesla list"
To:
Sent: Wednesday, October 18, 2006 6:38 PM
Subject: Re: 3 phase car alternators


> Original poster: Tim S
>
> i might just do this experiment as i have an acdelco 108 amp(pre 1980 i
think)
> with internal diodes allready removed and i also removed the
> internal module that regulates the field winding.
> so i have a bare bones setup.
>
> once i thought since the field winding is a north south static
> polarity why not use a mosfet bridge and modulate the field winding
> with a frequency say 60 hz and see the result of the 3 phase
> windings.i am sure due to the iron claw core that is inside covering
> the field winding there will be some frequency that the field coil
> will saturate at but i really don't know the answer.that is why i was
> experimenting in the first place.
>
> i started this idea 8 months ago and due to other things always
> popping up i never got to finish this idea.
> tim
>
>
> Tesla list wrote:
> Original poster: Jeff Larson
>
> About 15 years ago when I started playing with Tesla coils my friend
> and I were looking for sources of high voltage since we had burned
> out the transformers that we had. We had taken apart a alternator
> and removed the diodes and extended the stator windings out of the
> case. I think we just fed them through holes in the side. This was
> C clamped to the welding table. We then put a 18 inch pulley on a 8
> Hp Briggs and Stratton gas engine that had a horizontal shaft. The
> engine was also mounted to the welding table so that a belt was
> placed on the large pulley and the tiny pulley of the
> alternator. The speed ratio between the engine and the alternator
> was huge. Like maybe 1 to 9. Any way,
> the engine was started and run up to speed. The alternator was
> singing at a high speed. Then 12 volts was applied to the field
> winding, or was it 24, I don't remember. What I do vividly
> remember was the hot arcs that jump between the stator wires sticking
> out in the air. It was like a Jacobs ladder. Man did that put a
> load on the engine. It would bog the engine way down until we
> removed the voltage on the field winding.
> I don't know how much voltage was on stator, but the wires must have
> been about 1/4 to 1/2 inch apart. So maybe 10kv. Imagine that! We
> didn't use it for anything, but it was fun.
> I think someone out there needs to revisit this experiment. Who has
> the stuff , and the time? A challenge. We will want to see video.
> Jeff Larson
>
>
>
>
>
>
>
>