SSTC newbie

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

Original poster: "Alan Sharp by way of Terry Fritz <twftesla-at-qwest-dot-net>" <AlanSharp-at-compuserve-dot-com>

Shad,

IRF740 is fine for 180V but a bit tight at  350V.

> Is it a necessity to use 2 separate gate transformers, or can I wind 
>them both on the same core?  I have a very nice ferrite core transformer 
>that has plenty of room once I remove the old windings from the bobbin. 
Is 
>the gate transformer simply a 1:1 isolation transformer (what it looks to 
>be in most of the coils I've seen)?

Your first question is interesting - you could try the experiment.
Your ferrite core transformer is probably an overkill - lots of
leakage inductance as you are trying to switch the FET in say 50nS,
you need to minimise stray induction, so small transformers, short leads. 
It is a 1:1
isolation tranformer - most folks use small ferrite toriods say 1 inch
diameter,
twist the 3 wires together to improve coupling and then wind about 10 turns
around the toriod.

Use a variac to bring up the voltage - scope the driving voltage across the
FET gates.

If you are looking for an off the shelf design then Richie Burnetts design
has been
copied sucessfully by a few others:

www.richieburnett.co.uk 

my own efforts are at   www.alansharp.co.uk

try not to blow too many FETs

All the best,

Alan Sharp


Message text written by INTERNET:tesla-at-pupman-dot-com
>
Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<sundog-at-timeship-dot-net>

Hi All,

   Well, after some bad luck with the VTTC frontier, I'm looking at 
building a solid state coil.

    So begins the wallet-draining venture into SSTC's....I'll get the tiny 
boxes ready for the MOFSET's funerals...some of them will probably be 
cremated on the spot and their ashes scattered with canned air ;)
Any of the veteran SSTC'ers that want to help are more than welcome to 
contact me off-list.  Thanks All!
  Shad  G5-1203<