[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: TSG beginner Questions



Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>



Tesla list wrote:
> 
> Original poster: "Patrick Bloofon by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <transactoid-at-home-dot-com>
> 
> Just a few questions regarding triggered spark gaps for a beginner...
> 
> 1) This is my first coil and I just want to get sparks...do they work
> considerably better than an RQ spark gap?  They do seem easier to build...

Why not just rig up a straight vanilla static gap... You'll get plenty of
sparks, and tuning your primary is probably easier with fewer things to
worry about

> 
> 2) I'm was looking at this site and it had a nice simple TSG:
> <http://www.fortunecity-dot-com/meltingpot/syria/1210/id42.htm>http://www.fortu
> necity-dot-com/meltingpot/syria/1210/id42.htm
> What is a "motor run capacitor" and do I really need one?

A motor run cap is one that is designed for 100% duty cycle (as opposed to
the smaller, cheaper motor start cap which is designed for <10% duty cycle
(if that)).  Yes you need it.  It limits the current through the ignition coil.

> 
> 3) What does the dimmer switch do? How does it control the SG?

A standard dimmer is basically an electronic switch that turns on sometime
after the zero crossing.  The later in the cycle, the less power gets to
the load (the light bulb).  In the TSG case, when the voltage hits the
coil, you get a spark, and the gap fires. Delaying the turn on (i.e.
dimming the light) makes the trigger occur later, relative to the phase of
the AC that is charging the primary cap.

The idea is to trigger the spark gap as the primary cap reaches peak
voltage, but not before.  With a static gap, one carefully fiddles with the
spacing to achieve this. The problem is that the breakdown voltage tends to
vary with the breeze, the temperature of the electrodes, the phase of the
moon, etc....  With a triggered gap, same spark same time, every time.


> 
> 4) Do I still have to adjust the spacing between the gaps? It seems to me
that
> setting the initial gap spacing would be difficult.

yes, but... You can set the gap the same way you set a standard static gap,
except a bit farther apart.


> 
> 5) Finally, is there a way to test the TSG? Like could I wire up a cap and my
> NST to it just to generate sparks? (ie, tank circuit minus the primary and
> secondary).

You could, but why bother... running just the primary tank cap and the NST
without the primary and secondary is a good way to destroy a cap (i.e. with
no load, the voltage gets higher...excess voltage on the cap == short life)

> 
> BTW, I will be using a 15/30 NST for starters (with plans to upgrade) and
8 SW
> caps.
> 
> Thanks,
> Patrick