Re: Hard Drive Motors, RSGs and Stuff

[FutureT-at-aol-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

In a message dated 7/17/00 11:25:45 AM Pacific Daylight Time, 
tesla-at-pupman-dot-com writes:

> Original poster: "Troy Peterson" <highvoltage-at-mad.scientist-dot-com> 
>  
>  Hi all, 
>   
>  It's been a while since I've posted to this list, but coiling has been 
good 
> for
>  me. While I am still looking for a solution to my capacitor problem 
(Bottles
>  are too lossy and big for my coil, but thats all I have...) Some other
>  questions have finnally gotten the better of me. Firstly, what exactly is 
> the
>  diference between a syncronise RSG and an Asyncronous RSG. I have an idea: 
> it
>  has to do with firing, a sync gap always fires on the peaks or something, 
> but
>  please elaborate.

Troy,

The sync motor is "locked" to the 60Hz line, it runs at exactly 1800 rpm
or 3600 rpm.  The firing time or position along the 60 Hz sine wave will
occur at the same exact spot every time.  By rotating the motor or the
electrode holder to a certain position, the firings can be adjusted to
fire at the AC peaks as you said (assuming 120 bps).  Sync gaps can
also fire at a higher bps such as 240, 360, 480, or higher multiples of
120 bps.  However I have found the 120 bps to the most "efficient" 
when the coil is properly designed.

If the coil is not properly designed, then one might replace a higher
speed sync or async gap with a 120 bps sync gap, and get poorer
results rather than better.  Because of this, the design of a 120 bps
sync gap TC is more demanding than an async TC.  Mainly, the cap
must be of the correct size for the power input, etc.  With an async
TC,  one can simply adjust the bps to compensate (to a degree) for 
a cap that is too small.  Most coilers who are just getting involved
with rotaries start with async gaps.  However if you plan to use the
rotary with an NST, then a sync gap should be used because async
gaps tend to destroy nst's.

You can see some of my work at:

   http://hometown.aol-dot-com/futuret/page1.html

Cheers,
John Freau