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Re: LTR Charging vs. Firing Time
In a message dated 99-06-21 16:21:29 EDT, you write:
<< Hi Terry:
> While it's clear how to adjust a simulation for optimal sync RSG timing,
> how do you adjust a real coil? Is it sufficient to simply rotate the
> sync motor in it's cradle for maximum arc length, or do you scope the cap
> charging voltage vs. AC mains voltage at a low variac setting and adjust
> the motor phase, prior to cranking up to full power? I know that it
> would be bad to apply power when the phase is 90 degrees away from peak
> (zero cap voltage at gap presentations)...
> Regards, Gary Lau >>
Gary,
In my reso-cap days, I used to just rotate the motor for best spark
length, starting at low power to prevent the zero cap voltage at gap
presentations, then crank up the power and rephase as needed at
full power. I like to place a numbered dial onto the motor cradle, with
a pointer on the motor. The proper phase settings can be made
into a chart that shows the proper phase settings for various
sized caps, NST's, etc. Now of course I'm observing everything
on the scope, but it's not necessary, but really nice to see.
In any case, even if you started the system at zero cap voltage
at presentations there would probably be no problem, because
with LTR caps, the voltage remains lower when the gaps are not
firing than when they are firing. It doesn't matter if presentations
are missed, etc. This is still another wonder of the LTR - IK set-up.
I'm beginning to think that the large cap you're using is letting
the inductive kick effect occur strongly in your coil. Terry's cap
voltage peaks somewhat before his gap firing at 75 degrees. But
your larger (?) cap should delay the peak to perhaps around 50 to
60 degrees (?). You may be getting as much cap voltage as if you
were using resonant charging. I may look at this more if I get the
chance.
Cheers,
John Freau