Terry's DRSSTC

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

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>


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-dot-com/TeslaCoils/MyCoils/DRSSTC/DRSSTCinput.gif>http://www.hot-streamer-dot-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-dot-com/TeslaCoils/MyCoils/TubeCoil/