Re: Terry's DRSSTC

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Shad Henderson" <sundog@xxxxxxxxxxxx>

Hi All, Terry,

Beware running that VTTC like that!

811A tubes don't like to run on their side, unless the filament pins are
vertical!

The hot filament wire can sag close to the grid and cause a flashover.

Stand it back up and run it that way :)

Shad

On Mon, 2004-11-22 at 01:31, Tesla list wrote:
> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
>
>
> Hi All,
>
>
> I have been working on my DRSSTC :-) I have Dan's Resonant Driver Board
> put together without too many left over parts ;-) Real nice stuff Dan has
> figured out!
>
>
> Today I worked on the input section design. I went with a voltage doubler
> so I can run fully off 120VAC. I also added a bunch of heavy
> filtering/protection for the AC line.
>
>
> 
<http://www.hot-streamer.com/TeslaCoils/MyCoils/DRSSTC/DRSSTCinput.gif>http://www.hot-streamer.com/TeslaCoils/MyCoils/DRSSTC/DRSSTCinput.gif
>
>
> It runs off my 15 amp variac box so there is no soft start. The MOVs and
> hydraulic breaker protect the line from the usual over voltage and shorting
> events. The filter is a dual stage type to cut RFI and all that. The two
> diodes are slightly over rated since I hate blowing stupid diodes ;-) The
> 220uF caps and 1 ohm resistors form a low pass filter (might need poly MF
> bypass too?). Right now it is a rather low Fc frequency since I suspect
> that the resistance will have to be smaller in the long run. The resistors
> also happily control fault currents if things go nukies. The main caps
> are four 4700uF 200V caps and two 1000 ohm 100W resistors to drain them.
> Hmmm... Maybe those should have been 10K/25W... :o) No wonder I have so
> many extra parts laying around :D
>
>
> I think there should be some big poly caps right at the IGBTs. I note
> some of Dan's coil pictures show these. I worry that the big electrolytics
> may not like 300 amp 200kHz stuff and may wimp out. I have some 4.7uF 600V
> 500Ap polys that I can mount right on the IGBTs This may also relieve the
> need for such heavy copper buss work to the IGBTs. Electrolytics just are
> not RF things. Note the fancy stereo amps that have electrolytics for LF,
> film for MF, and mica for HF all in parallel for wide band frequency
> bypassing. This same input power system may have uses for OLTC stuff too,
> noting Steve's successes in heavy DC power for OLTCs ;-))
>
>
> I hope to run my existing coils off it. My big coil can play tuning tricks
> toward reducing primary current which helps the IGBTs. I could also make
> new coils, but later when I know what needs to be optimized.
>
>
> So I am trying to get a DRSSTC going here too ;-)) If all else fails,
> Gerry just got a pole pig :-))
>
>
> Cheers,
>
>
> Terry
>
>
> BTW  Details of my tube coil are at:
>
> http://www.hot-streamer.com/TeslaCoils/MyCoils/TubeCoil/
>
>
>
>
>
--


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