RSG -at- 60 Hz

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: RSG -at- 60 Hz
From: Tesla List <tesla-at-stic-dot-net>
Date: Sat, 9 Aug 1997 20:29:08 -0500
Approved: tesla-at-stic-dot-net

From: 	Rick Holland[SMTP:rickh-at-ghg-dot-net]
Sent: 	Saturday, August 09, 1997 4:57 PM
To: 	Tesla List
Subject: 	RSG -at- 60 Hz

Tesla List wrote:
 is it the phase angle (of the 60Hz signal)
> > that the gap fires at? If so does that mean that you adjust it by
> > rotating the rotor about the motor shaft until the contacts are firing
> > at the right spot? Surely there must be some part of the synch gap that
> > takes into account you res. freq. - everything you have told me so far
> > deals with 60Hz.
> 
> > Still slightly unsure,
> > TES
>   >>
> 
> TES,
> 
> Yes, your understanding is correct about rotating the motor to make
> gaps fire at the correct point along the 60Hz AC sine wave.  Just
> adjust the phase for best spark output.
> 
> I'm not sure I understand what you are asking about the resonant
> frequency.  I suppose you mean the RF tank and secondary
> resonant frequency, for example 250 kHz?   The sync-gap is not
> affected by the RF resonant frequency...a particular sync-gap can
> be used at any RF frequency without modification.  The gap does
> not synchronize to the RF frequency...it can't either.
> 
> John Freau

Pardon me, John while I stick my foot in my mouth. I believe TES asked
if the rotor should be adjusted on the shaft of the motor. The idea as I
understand it, is that the entire motor is turned in relation to the
stationary electrodes so that the phase is advanced or retarded as
needed.

As far as resonant frequency, the gap's purpose is to short (spark) at
just the right moment to dump the maximum voltage/current from the
supply transformer into the capacitor of the tank circuit. Here in
Texas, that happens 120 times a second. At the same time, this effective
short circuit puts the tank capacitor in parallel with the primary coil
where the cap's energy is dumped (through the spark) into the primary
coil and causes a ringing effect between the capacitor and primary coil.
In effect, they find their own resonant frequency and react to it. Of
course, some of this energy is reflected to the much greater inductive
impedance of the supply transformer, which is why it should be protected
from these much higher frequencies with choke coils and bypass
capacitors.
I release the podium to those more qualified.

    Rick Holland

    The answer is 42