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Re: Beating Solved
Tesla List wrote:
>
> > Subject: Re: Beating Solved
>
> >From bturner-at-apc-dot-netMon Sep 23 22:18:46 1996
> Date: Mon, 23 Sep 1996 12:02:09 -0700
> From: open_minded <bturner-at-apc-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: Beating Solved
>
> Tesla List wrote:
> >
> > >From sgreiner-at-mail.wwnet-dot-comSat Sep 21 12:10:53 1996
> > Date: Fri, 20 Sep 1996 16:46:09 -0700
> > From: Skip Greiner <sgreiner-at-mail.wwnet-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: Beating Solved
> >
> > Tesla List wrote:
> > <SNIP>
> > > Bert (and the gang) -
>
> <SNIP>
>
> >
> > Beautiful pics Brent. One question...How many breaks per each half cycle
> > of the mains does your synchronous break do.
> >
> > Thanks
> > Skip
>
> It's an 8-electrode, 1800-RPM sync. gap. I get 240 BPS out of it as it
> sits, so that's 4 breaks per single AC cycle, or 2 per half cycle. BTW -
> I just calculated out the dwell time, and I get about 40 uS, which
> is a bit too long. Details from the Corum Brothers suggest that I will
> do better with about a 20uS dwell, which I will get when I switch over
> to a 3600-RPM sync. motor. Will boost the BPS to 480 as well. Hopefully
> I'll get a bit hotter spark out of it!
>
> - Brent (...tuning for maximum smoke...)
Brent
Several questions which I hope don't bore you and others
1. Have you ever tried to use only 1 break per half cycle?
2. Do you phase the break points with the AC, ie., do you adjust the
break rotor with respect to the rotor shaft to place the break points at
a particular point in the AC cycle?
I have found at the 1 and 2 kva levels that I run that a single break
per half cycle at synchronous speed placed just before the peak is
extremely efficient. At my lower powers dwell time is not an issue since
the capacitor is pretty well discharged during its one chance. I have
tried 1, 2, 3, and 4 breaks per half cycle and have achieved the best
efficiency at 1 break per half cycle. I have varied the dwell time by
using smaller and larger contacts and both 1800 and 3600 rpm motors with
little change when set up as above.
Please publish your results at reduced dwell times and larger number of
breaks. It should help to better define the problems of runnung at
synchronous motor speeds.
Thanks
Skip