Re: Triggered Gap

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi CJ,

At 01:00 PM 12/9/2001 -0800, you wrote:
>A few questions about triggered gaps:
>
>1. Does the triggered gap have to be powered up at exactly the same time as
>the coil?

No, you can have it running before the coil.  If your coil uses a resonant
cap size, you should not run the coil without the gap going since the
voltage my ring up too high without the gap firing.

>2. Did anyone ever decide if it was safe to operate the dimmer while the
>coil was running

I do, but I have MOVs and heavy grounding on everything I touch.

>3. Is the control circuit for the gap absolutely necessary/does it increase
>performance?

You need the dimmer's electronics to do the high speed switching to run the
ignition coil.  Yes it is necessary.

>4. I saw Mark's gap b/f the big discussion on the list and I saw the
>original diagram with a 12 uf cap (Or something around there) so I got a
>motor run capacitor rated at 15 uf, now people are saying to use something
>around 2 or 3 uf, will my large size be a problem?

The ignition coil my get hot fast.  If it is sealed, it may even explode
from internal pressure.  Best to get the 2-3 uF or run for a short time and
keep an eye on the coil temperature.  DigiKey number P10945-ND is a nice
cap for this but two Radio Shack 1.0uF AC caps work too.

>
>
>-----------Not related to triggered gaps-----------
>
>I have seen people recommend putting safety gaps across the transformer, the
>capacitor, on the nst protection circuit, all over the place. Is there any
>disadvantage to having a large number of safety gaps, or are the two in the
>nst protection circuit all you need?

The two in the NST circuit should do everything.  One should not put a gap
directly across the primary capacitor since there is nothing to limit the
current (you can add a resistor).

>I have all of the parts from digikey that terry has on his circuit, but I
>can't seem to find the safety gap parts, Where do you get the standoffs?, I
>am assuming that the other part is just a bolt with an acorn nut on the end,
>please correct me if I am wrong.  

They are 1 inch aluminum standoffs from DigiKey.  I drilled and tapped a
hole in the side to hold the screw that has a brass acorn nut on the end.
A little set screw in the top holds the setting tight.  Another screw on
the bottom attaches it to the board and makes electrical contact.

Cheers,

	Terry


>
>
>Thanks,
>
>CJ
>