There's always a different way to do something. Have been reading a few threads about using TV damper diodes as HT rectifiers - a 6AL3 I think has only 29 volts drop at 400ma 
so it sounds like a pretty good way to go. Anyway, there comes a time when you would like to have a regulated supply. You can stick a tube in series with the dc line and run it like a dirty big cathode follower to supply your stuff. You can use a pair of triodes as the rectifiers with the grid voltage controlling the rectifier output votage.
Or another way I just thought of - use the damper diodes or some other indirectly heated diodes, and have the regulator feedback path control the heater voltage of the diodes. Reduced cathode temperature makes the diode conduct less and lowers the output voltage and vice versa. The response time would be very slow so it would be only suitable for a cct that drew a steady current like a Class A amp or a preamp or something. Wouldn't reduce hum or ripple, just keep the voltage steady, that's all.
Well, that's it.
so it sounds like a pretty good way to go. Anyway, there comes a time when you would like to have a regulated supply. You can stick a tube in series with the dc line and run it like a dirty big cathode follower to supply your stuff. You can use a pair of triodes as the rectifiers with the grid voltage controlling the rectifier output votage. Or another way I just thought of - use the damper diodes or some other indirectly heated diodes, and have the regulator feedback path control the heater voltage of the diodes. Reduced cathode temperature makes the diode conduct less and lowers the output voltage and vice versa. The response time would be very slow so it would be only suitable for a cct that drew a steady current like a Class A amp or a preamp or something. Wouldn't reduce hum or ripple, just keep the voltage steady, that's all.
Well, that's it.
Controlled rectifiers..
Yes, I've thought of triodes (or pentodes) as controlled rectifiers.
They could be useful for evening out the long-term mains variations. They hardly make for a low Z poder supply though!
Hum / ripple would reduce as the mains voltage rose.
Damper diodes? Hmm, you could watch the voltage cycle at about 1/60Hz. That should be fun Just slightly faster than paint dries
Cheers,
Yes, I've thought of triodes (or pentodes) as controlled rectifiers.
They could be useful for evening out the long-term mains variations. They hardly make for a low Z poder supply though!
Hum / ripple would reduce as the mains voltage rose.
Damper diodes? Hmm, you could watch the voltage cycle at about 1/60Hz. That should be fun
Just slightly faster than paint dries Cheers,
thanks for the interest..
Circlotron,
dhaen is an internet friendly corruption of D'Haen which is my old family name from Belguim. It means cockerel.
My avatar says de, ha, e, n starting from the top right down.
It's written in Katakana which is a Japanese script type used for foreign words. I'm a bit of a Japanese culture and language freak
The local time is 15:40. What's yours?
Cheers,
Circlotron,
dhaen is an internet friendly corruption of D'Haen which is my old family name from Belguim. It means cockerel.
My avatar says de, ha, e, n starting from the top right down.
It's written in Katakana which is a Japanese script type used for foreign words. I'm a bit of a Japanese culture and language freak
The local time is 15:40. What's yours?
Cheers,
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