Re: Oriental motor

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>

Christoph -

To the best of my knowledge (& the knowledge of the Oriental Motor Co.
technical sales office in the US), Oriental does not make nor has ever made
salient-pole synchronous AC induction motors. (If anyone can demonstrate
otherwise, please let me know!)

They make a multitude of different models of synchronous AC induction
motors, but none of these are of salient pole construction. As discussed at
length on this list, standard synchronous AC induction motors can be
modified for salient-pole operation by machining flats on the rotor.

For standard AC "synchronous" induction motors, "synchronous" just means
that the rotor locks into an operating speed that is dictated by the AC line
frequency and the number of magnetic poles the motor is built with (physical
magnetic poles on the rotor and stator lamination stack). Standard
synchronous induction motors will have multiple possible rotor positions
when the motor achieves "lock up"  & synchronizes with line frequency.

For 60Hz line frequency, 3600 RPM salient pole motors will have only two
possible rotor positions at lockup (180 degrees apart); 1800 RPM motors will
have four possible rotor positions (90 degrees apart). If you build your RSG
disk with electrodes in multiples of (2) or (4), the (2) or (4) possible
"lock-up" positions won't matter because you will always have a
flying/stationary electrode pair coming into alignment.

I believe that if Terry Blake checked his motor with a real stroboscope
synchronized to the AC line, he would find that it was NOT a salient-pole
motor.

Regards,
Scott Hanson
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Sunday, May 01, 2005 2:09 PM
Subject: Oriental motor


> Original poster: "Christoph Bohr" <cb@xxxxxxxxxxxxxxx>
>
> Hello everyone.
>
> I want to build another small SRSG.
> I have a small oriental motor, just like the one
> Terry Blake used in his 12BPS gap.
> http://www.tb3.com/tesla/sparkgaps/1800srsg/1800srsg.html
> I just have the 220V version as far as I can see.
> I made a small 11cm disk with 4 spinning electrodes
> traveling on a 9cm diameter.
> I attached a white strip to the disk an checked for
> sync operation but the only flourescent light I have is
> a streetlamp in front of my window... just too weak.
> TV seems not to be too stable to be used and computer
> monitor just won't accept 50 or 100Hz as rep frequency.
>
> However, my impression was, that the motor locks into
> different positions each time I turn it on. Looks to me
> as if there are 8 possible positions, but this might be
> a wrong ebservation due to the very limited light...
>
> Or am I messing things up? I think there might be several
> possible positions in which the electrodes would still align
> properly....
> Maybe someone can help here...
>
> Thanks in advance
>
> Christoph Bohr
>
>