kevin gilmore Posted March 16 Report Share Posted March 16 So this started a few weeks ago when someone found a picture of my 100 watt night light. Its an 833A tube. (new picture below) And he wanted a megatron made from 8 of these. (10 vac at 10 amps each tube) so 800 watts filament power just for the output tubes. By the time you make the +/- 1kv power supplies running at 40ma, and the power for the 300b driver tubes etc, way past the limit for usa 120v 20 amp service which is 1850 watts. And with the top of the tube at silly and dangerous high voltage... bad idea. So i started looking for slightly less silly alternatives. I think the 211 tube fits the bill. running with +/-750v power supplies at 35ma. So a megatron with 211 output tubes, 300b drivers and a high gain input tube. unless someone has a better idea. 8 Quote Link to comment Share on other sites More sharing options...
spritzer Posted March 16 Report Share Posted March 16 This might be too crazy for me but why not go further. I happen to have a couple of 30kWh, 400V battery packs so a DC-DC converter and make it "portable"? 1 1 4 Quote Link to comment Share on other sites More sharing options...
G600 Posted March 16 Report Share Posted March 16 March madness, redux. Was the original March madness in 2013? Quote Link to comment Share on other sites More sharing options...
jamesmking Posted March 16 Report Share Posted March 16 2 hours ago, spritzer said: This might be too crazy for me but why not go further. I happen to have a couple of 30kWh, 400V battery packs so a DC-DC converter and make it "portable"? portable if you are godzilla or king kong.... 1 Quote Link to comment Share on other sites More sharing options...
simmconn Posted March 19 Report Share Posted March 19 I like the idea with the 211. It also helps keeping the noise from the filament supply at bay with the common cathode configuration. If matching tubes for the CCS sounds too much, we can always consider the 1700V depletion mode SiC JFET. Thermal management is going to be a challenge though at 35ma. Quote Link to comment Share on other sites More sharing options...
TammerDown Posted March 29 Report Share Posted March 29 Can we call it juggernaut? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted March 29 Author Report Share Posted March 29 i like that. i also like "david and goliath" Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted March 30 Author Report Share Posted March 30 (edited) there will be 4 output boards. 12 x 6 inch each. filament boards will stack on them, each filament board will have 5 x 5v 4a switchers. 2 switchers in series for the 211 so chassis is likely to be a bit over 24 inches wide and 20 inches deep. updated picture Edited March 30 by kevin gilmore 3 Quote Link to comment Share on other sites More sharing options...
Emooze Posted April 3 Report Share Posted April 3 Sign me up, probably be cheaper than paying for heat in the winter. Quote Link to comment Share on other sites More sharing options...
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