Re: SRSG questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Christoph Bohr by way of Terry Fritz <teslalist-at-qwest-dot-net>" <cb-at-luebke-lands.de>

Hi!

I think we have a  similar problem....and greetings to finn hammer from here
as he gave some help to me, too concerning this topic.

I finally tried  to run the gap via a variac and really found, that at lower
voltages the hunting disappeared. But when I reach this point at about 170V
( on a 240V line ) the speed seems to be much lower than with full voltage.
I have use an ordinary fluorescent light an a mark I attached to the disk
and the visable image turned counterclockwise with ca 1/3 Hz which I assume
means i can't run at 3000RPM ( 50HZ ). With the variac I can widely vary the
speed of the motor and I'll probalbly try to use more electrodes to get
someting like an 300 to 400 BPS async gap if anyting else fails.
using higher voltages only increased the effect and the motor got really
hot...

good luck with your gap, maybe your motor is more cooperative ;-)

Christoph



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, April 22, 2003 9:13 PM
Subject: Re: SRSG questions


 > Original poster: "Finn Hammer by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<f-h-at-c.dk>
 >
 > Chris,
 >
 > Start the motor up with the disk attached, and preferably with the
 > moving electrodes installed, using a variac and an analogous
 > amperemeter.
 >
 > As the motor gains speed, the meter is going to show variations in
 > current draw, this will be accompanied by sound from the motor. This
 > behaviour is called hunting. You will recognize it immediately when you
 > see/hear it. Increasing the voltage should produce the effect that the
 > variation finally stops, and a steady current draw results. This means
 > that the rotor has locked to the rotating field. It has become
 > syncronous. If it does not lock in, take more off the armature. If you
 > take too much off, don`t dispare, you just have to run it at a lower
 > voltage, which means that the gap is going to need it`s own variac.
 >
 > Cheers, Finn Hammer
 >
 > Tesla list skriver:
 >  >
 >  > Original poster: "Zagarus Rashkae by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <arbitrarily_random-at-yahoo-dot-com>
 >  >
 >  >  >  > Trouble is, I'm stuck with a brand new 1/2 HP GE
 >  >  >  > induction motor... and I want to make it
 >  >  > synchronous.
 >  >  >  > I will see if I can obtain an angle grinder (for
 >  >  >  > ARSGs) for a reasonable price though.
 >  >  >  >
 >  >  >  > Chris
 >  >  >  >
 >  >  >
 >  >  > Oh I see.  Anyways, Grainger has some nice universal
 >  >  > motors, ranging from
 >  >  > small to about 1 HP in size.
 >  >  >
 >  >  > The Captain
 >  >
 >  > Well... I just milled some flats in the rotor and now
 >  > I don't know if it's synchronous. I'm pretty sure it
 >  > is, but how can I check for sure? Also, is a .8-.9
 >  > inch flat enough for a rotor 2-2.5 inches in diameter?
 >  > I'm running at 3600 RPM.
 >  >
 >  > Thanks,
 >  >
 >  > Chris
 >  >
 >  > _
 >
 >
 >
 >