Re: Ryobi Bench Top Grinder ?? In Sync??

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 5/19/03 6:40:09 PM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:

>How do you tell if the SRSG is in sync?


Nolan,

You can observe the spinning rotor under fluorescent lighting
(ballast type).  If rotor is locked in sync, pattern will be stationary
(not rotating).  If not synch'ed, pattern may rotate or not be visible.
Use a variac to raise the voltage, and at some voltage the motor
will go into sync, and drop out of sync as you lower the voltage.
As you raise voltage, and just before it locks, the motor will make
a hunting (uneven) sound.  Some folks have some trouble seeing
the pattern, but with practice it's very easy.  Some folks put a dark
line or white tape across the rotor to make it easier to see.  The
pattern will be extremely blurred, which is why it takes training to
be able to see.

Some folks like to build or buy a strobe with gives a clearer view
of things.


>When I ran my SRSG and it gets to full speed and I used a 15/60 nst it will
>jump across the safety gap up to one inch this is not a needle gap so why is
>it jumping a safty gap 4 times wider than it should be able to???


This could happen if it's not synch'ing, or if the phase is not adjusted
correctly.  Phase is very important with a synch rotary gap.


>How should I set my safety gaps?
>
>Also if I use a variac to power my SRSG will it come in to phase at
>different voltages?


A variac will give some slight degree of phase control.  For more
electrical phase control, see my simple schematic for a phase shifter
circuit at:

   <http://hometown.aol-dot-com/futuret/page3.html>http://hometown.aol-dot-com/futuret/page3.html


>What is the Ideal topload formula?


Depends on such factors as power input, efficiency, break-rate,
capacitor value.  A 15/60 NST with sync rotary gap and good design
can tolerate a 6" x 24" toroid or larger, and can give a 60" or longer
spark output.

John


>Thanks!
>
>Nolan Moore
>