Re: Tesla coil tank circuit based on cap discharge through an SCR

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Fucian-at-aol-dot-com>

In a message dated 6/27/01 9:44:02 AM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes: 


>
> If we are talking a resonate transformer design one SCR would not work. The 
> current between the primary and cap is a damped oscillation (AC). Two SCRs 
> in parallel (or TRIAC) might work but it might be a little tricky triggering 
> them. If you just want to hit the primary with a big capacitor discharge 
> that would work but it would be just a basic step up pulse transformer (not 
> much HV compared to a resonate Tesla coil design). Also the SCR voltage 
> would have to be rated not for the capacitor voltage but the back EMF 
> (kickback) generated in the primary after the field collapses. The real 
> problem is you would, even for a small setup, need very large SCRs that 
> could handle high surge current. Also if you don't trigger them properly 
> even correctly sized one can be destroyed. That's way spark gaps are so 
> popular. 
>
> If you are still interested in this there is a type of car ignition system 
> called a capacitive discharge (CD) that charges a cap to 300V or more and 
> using an SCR connects the cap to the coil. You might be able to find 
> schematics for one on the web. 
>
> Ray 



Yes, I know about CEMF.Wouldnt a large diode work?If i t was in series with 
the SCR?And triggering 2 scrs is wayto complicated.Its not worth it when a 
simple spark gap could be used.This could be goodfor maybe an ignition coil 
type though.For a gib pulse.Kinda like a MARX generator. 

Oh well, 
It was just an idea.Thanx anyways guys, 
Matt