[Prev][Next][Index][Thread]
Re: Rotaty popping, (Was Re: commercial cap failure)
> Original Poster: "Robin Copini" <rcopini-at-merlin-dot-net.au>
>
>
> Hi jon, Ed.
>
> I noted to the list, last month about this same occurence.
> Have you checked the firing point on the incoming wave form
> in relation to your SRSG. If mine is at the wrong point, the thing
> sounds like a 'dog' and I get continual 'backfires' across the
> safety gap. Just changing the firing angle turns it into a pussy-cat.
I "timed" my SRSG using the trial and error method. I rotated the motor
housing in 5 degree increments, and then 2 degree increments, until I
achieved max spark and max input current, (they coincided). I did this three
different times, all with the same result. The "happy" firing point seems to
be quite critical, within a 2 or 3 degree range.
Just to confirm, my coil runs quite smooth. I have heard a sound like a car
door slamming just a few times, and when I did hear that sound I didn't
notice anything else happening, no safety firing, drop in output sparks, not
even a hiccup. (Heck, maybe what I heard was a car door slamming).
> Could it be that as you change the level of control inductance with
> the welder, you are also shifting the phase of the waveform in
> relation to the srsg firing point? - I bet the srsg motor supply is
> not coming out of the welder - it's coming straight from the wall.
I'm wondering about that myself. I have my SRSG motor, (120Vac), tapped into
the 120Vac terminals of the variac.
Another thing that I have noticed with my coil is that maximum input current
is at 210Vac. When I turn the input voltage up past 210Vac the input current
starts dropping, (no matter where the inductance is set or how much or how
little parallel resistive ballast in switched in). Welder ballast resonance?
Phase shift?
I need to do a few tests to see if I can determine why the input current
drops off above 210Vac.
Geez, so many things to understand. Is this a great hobby, or what?
Regards,
Jon Rosenstiel