Tube based PWM at about 150 kc. (hey, it's tubes so kc is right...)
The reason I depict R1 as going to the plate is because it technically must . In this app the load might be on the ngative side. That is, like in a tot em pole arraingement.
It's obvious what a screen grid does kinda, but I am not so sure. I am not sure exactly how to run this. I want maximum current and the ability to acc omplish PWM at 150 kHz. I know the tubes will not be cheap of course. the r eason for tubes is that I want about 5 kV output. I lso know this is insane , but so what.
Z1 keeps the thing from melting in the absence of excitation of course. I d on't need to pull a Sony with this type of components for a damn open 15K r esistor way in the other side of the thing. that much is fine acually, what I don't know is what to do with the screen grid.
If I just connect the screen to the plate that is like a triode right ? If I lower the screen voltage from there what happens ? It has something to do with the gain. I don't want to have to pump these things with more voltage than they put out. I am already going to find T1 because it may have to ta ke the full output voltage.
This is how the rest of it looks :
As you can see, to make a sceeen supply separate makes for a few problems. I do not intend to go through what it takes to make for example this :
One of them in stereo would best be done with like three power transformers . Count me out.
Now they still do make tubes right ? ofr audio purposes for one, but that w ould be no godd for this app because no output tube could handle 5 kV. tisi s in the realm of a TV horizontal output. Actually more like maybe the tube s used in linears for CB radios. Well not legally, they take ten meter ham jobs and retune them a bit. (that part for our overseas folk who might not know what "breaker one nine" means)
Anyway, the exact purpose of this thing is not important. I need to know ho w to most efficiently use the tube. Figure a pentod power tube like maybe a 6JE6 (??) or something like that. 6MJ6 maybe ?
At that point, bias the screen like I did, or tie it to the cathode, anode, no node or what ? Of course I want it to conduct like all hell to keep it more efficient. At the same time I need it to switch fast and I don't need any strange ions floating around in there. (or whatever)
One other question, related but...well, the plate voltage will not be pulle d negative from the screen voltage will it ? Or will it ?
Thanks. Ideas ? Anything but calling me a lunatic. I get enough of that fro m the locals...