Re: Advice for an Old Coiler

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Dave,

It sounds to me like it should work if it's syncing at the same spot .
That's good news. The
only thing left is if it can stay in sync under load. Good job with the
testing.

Take care,

Bart

Tesla list wrote:

> Original poster: "Dave Kyle by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<dave-at-kyleusa-dot-com>
>
> John,
>
> Thank you for suggesting this test. My previous tests failed as I did not
> take into account how dim the sync pattern would be. The disk made all the
> difference.
>
> The motor is labeled a Reaction Synchronous Motor made by Oriental Motors
> model 5SK25A-AULA 1800 RPM 1/30 HP at 115 volts using a 3uf start up cap
> http://www.omusa-dot-com/automated/product/3.htm.
>
> I placed a 3 inch Styrofoam disk with a black line half way across it on the
> motor. After testing every fluorescent light in the house I finally found
> one with low enough persistent phosphor to yield results. As expected the
> pattern was a cross since at 1800 RPM the disk should sync at four points.
> This motor appears to always sync in the same location as I repeatedly
> stopped and started it and the pattern was always in the same spot relative
> to the motor housing. A second attempt with a neon light source gave the
> same results.
>
> It is my belief that provided that 1/30 HP is strong enough to spin the disk
> it will work for a SRSG.
>
> C&H sales http://www.aaaim-dot-com/CandH/index.htm in Pasadena, CA has loads of
> these new for about $39.
>
> Dave
>
> =========================================
> Dave Kyle
> Austin, TX USA
> Email: dave-at-kyleusa-dot-com
>
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Thursday, July 19, 2001 12:50 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Advice for an Old Coiler
>
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <FutureT-at-aol-dot-com>
>
> In a message dated 7/19/01 10:47:46 AM Eastern Daylight Time,
> tesla-at-pupman-dot-com writes:
>
> >  My synchronous motor may need to be replaced as I am unsure if it is of
> the
> >  type that syncs from the same position at startup. It is a brand new
> >  synchronous motor from Oriental Motor. Has anyone any experience with
> these?
>
> You can test the motor by placing a cardboard disc onto the shaft as
> a rotor, and draw a white or black line across the disc.  Then run the
> motor under fluorescent lighting.  You will see the pattern "lock up"
> at a certain variac voltage.  Start and stop the motor a few times to
> see if it locks at the same position every time.