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Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
Steve- Thanks Actually it is a "tetrode" connection, with g1 to the feedback and g2+g3 to a tap on the HV transformer (through some RC filtering and a fuse).
Registered Member #3806
Joined: Sat Apr 02 2011, 09:20PM
Location: France
Posts: 259
Dr. Dark Current wrote ...
Phil, I posted the coil in the "Add your Tesla coil here" thread. Seems not much people acutally check it out. See here:
I'm using the GU-81M russian pentode.
PS, you can't full wave rectify a MOT and ground the negative output, because one end of the secondary is connected to the core and you'll most likely get an arc over to the primary of the transformer. Or leave the negative floating, but then you'll need to use a filament transformer with at least 3kV isolation between the windings.
Great coil, very neat building, I like it !
The circuit I'm planning is a plasma tweeter, I think I can let the -HV floating. But It's a good thing you pointed out possible issue with the filament transformer isolation, I wasn't thinking to that ... (That's where I realise I gotta be much more careful with my designs) Thanks Dr. DC for your post
@Steve: When I started this topic it was a general HV question, but it drifts towards TC's :p you may want to move it to the TC section
Registered Member #3806
Joined: Sat Apr 02 2011, 09:20PM
Location: France
Posts: 259
I ordered 3 more of these nice MOTs for future use
I'm gonna use two of them in my "coming soon" HFVTTC, as suggested by Steve
Steve Conner wrote ...
The solution is to use a voltage doubler. Then you can ground both the core and the negative output. Indeed that is why MOTs have one end of the secondary connected to the core, because they are designed for use with a doubler.
You get twice the output voltage, which you may not want, but you can fix that by reducing the input voltage to 120V.
You also have halfwave rectification, but you can fix that by using two MOT/doubler arrangements 180 degrees out of phase. (and maybe connect the primaries in series for 240V operation?)
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Question about MOT output voltage
Actually it is a "tetrode" connection, with g1 to the feedback and g2+g3 to a tap on the HV transformer (through some RC filtering and a fuse).
