Re: More SSTC Questions

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

Original poster: "Jan Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>


Hi!

>>  See http://www.hut.fi/~jwagner/tesla/SSTC/555-forward-cvt.gif for
>>  proper overvoltage protection.
> LOL, ok i think ill get this going.I am going to get every part on the
> schematic.I have most.I have about 10 CMOS 555s.
> And some IRF840 mosfets.And
> diodes....I just need those resistors and capacitors.I have a Q.On the
> schematic it looks like you put microfarads.But in the email you put
> nano.Whicj is it?

Probably was a typo. The schematic is correct. Although, my "n"
sometimes loooks like a "u"... 

So the caps are correctly: two "FKP"-type i.e. blue or red
470nanoFarad 100VAC caps or even higher capacitance like 1.0
microFarad each. If they don't read FKP or MKP (or FKP1 or so) then
the caps are no good for this purpose.

Then other is a 22microFarad larger than 200VDC electrolytic. What I
use is 220microF 350VDC from a dead PC powersupply which is the
cheapest place for larger HV electrolytics.

This is all assuming you have 110VAC mains. If you have 220VAC, then
small caps are 250VAC and electrolytic is 350VDC.

Good luck! Let's hope your mosfet survives longer! :o)

Umm and yeah dont forget to put the whole thing with mosfet and all
inside a small metal encasing (or some box/parcel with aluminium foil
wrapped on the outside). The mosfets don't like the high voltage
induced or coupled from the TC secondary - I've had a few mosfets fry
this way due to gate-source overvoltage, despite zener diodes on the
gate and everything. So put everything in a shielded box.

cheers,
 - Jan

--
*************************************************
 high voltage at http://www.hut.fi/~jwagner/tesla