Re: Rotary phase adjustment

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

Original poster: "Jon Rosenstiel by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jonr-at-pacbell-dot-net>

Ed,

I've found that with 120bps it's necessary to de-couple the secondary somewhat,
the bang is just too big for tight coupling. (Geez, why can't we have it all)!

The way I determined if I was firing at 120 or 240bps was to touch the rotating
electrodes after a run. If it was firing at 120bps only 4, (in my case with
1800rpm motor), of the rotating electrodes were warm. When it fired at 240bps
all 8 were warm.

By the way, with my 6" coil I've had best results using 120bps with the
secondary raised 1.75"

Jon

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, April 19, 2001 11:00 AM
Subject: Rotary phase adjustment


> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Esondrmn-at-aol-dot-com>
>
> I was working with my 3.0" coil the other night and noticed there are two
> points of adjustment on the phase angle control variac where the coil runs
> smoothly.  I find these points by turning up the power to about 30% and then
> adjusting the phase control to where the safety gaps quit firing.  The gaps
> are brass cabinet knobs and if I remember correctly, are set to somewhere
> between .35" and .40".  One position is clearly 240 bps and I can get to full
> power here with the safety gaps not firing if adjusted just right.  The coil
> runs well, smooth and with a constant tone.  The other position seems to be
> firing at 120 bps.  I can tell by watching the gap (my control position is
> only about 8 feet away), it is uncovered and you can see that it is locked in
> at a different place.  The performance of the coil is also much different.  I
> have two toroids on this coil, just like on my 6.0" coil.  The first toroid
> is mounted just about two inches above the top of the secondary then a larger
> toroid is mounted on a hollow aluminum spacer up about 6.0" above that.  When
> firing at 120 bps, there is a very intense corona coming downward from the
> lower toroid with discharges to the strike rail.  This is happening at about
> 60% of full power.  I cannot increase the power above this level at 120 bps
> as the safety gaps will not quit firing.  It is obvious that the tank voltage
> is much higher in this mode and the secondary spark activity is much more
> intense.  I would like to open up the gaps and give it a full run in this
> mode - but when I was first testing this gap a few months ago, I tried
> running it at 120 bps and burned up the secondary.  I really don't want to do
> that again.
>
> When I get this set up on my 6.0" coil, running at 7 kva, the rotary gap will
> be located in the cabinet below the coil and I will not be able to see it
> fire.  I definitely want to start out running it at 240 bps.  I guess I can
> determine whether I am at 240 or 120 bps by finding the spot where the safety
> gaps can be set the closest and still run at a given power level without
> firing.  The lowest setting would indicate the correct 240 bps rate.  It is
> nice that John's control circuit provides the option of running at either
> rate - but mandates that you know how you have it set up.
>
> Ed Sonderman
>
>
>