As the title suggests, I want to build a variable power supply that allows me to supply valve amplifier prototypes with a B+ supply on the fly.
It beats having to have a hefty (and damn expensive) stock of different power transformers around.
Here's what I've considered to this point:
-Putting a high-wattage potentiometer/variable resistor in series with the primary of say, a 600VAC transformer. Rectification would give me up to 800V easily.
-Making a multitapped transformer, that would allow me to change primary windings to modify the output voltage.
-Variac supply, which I don't want to do, knowing the exorbitant cost of Variacs and that I'm working on a student budget.
I don't want to jimmy down the output using resistors, as that would require I have a large stock of varying resistances around and would also assume I have a pretty well-factored load. With building tube amps, only so much can be garnered from the datasheets and at least to me, nothing beats mocking them up on a breadboard to test that everything operates as it should.
Ideally I'd like to build a constant voltage source, that is, one that would hold the output voltage within a certain degree assuming the load changes a reasonable amount, but how exactly I'd go about this dictates whether indeed that is possible. It doesn't need to go to an extreme degree, say 600V max. The larger RF tube projects I'd still break down and buy a transformer that would give me dedicated output voltage for my needs.
Does anyone have any ideas? I've tried googling this, but information on builds of this type seems pretty scarce.
It beats having to have a hefty (and damn expensive) stock of different power transformers around.
Here's what I've considered to this point:
-Putting a high-wattage potentiometer/variable resistor in series with the primary of say, a 600VAC transformer. Rectification would give me up to 800V easily.
-Making a multitapped transformer, that would allow me to change primary windings to modify the output voltage.
-Variac supply, which I don't want to do, knowing the exorbitant cost of Variacs and that I'm working on a student budget.
I don't want to jimmy down the output using resistors, as that would require I have a large stock of varying resistances around and would also assume I have a pretty well-factored load. With building tube amps, only so much can be garnered from the datasheets and at least to me, nothing beats mocking them up on a breadboard to test that everything operates as it should.
Ideally I'd like to build a constant voltage source, that is, one that would hold the output voltage within a certain degree assuming the load changes a reasonable amount, but how exactly I'd go about this dictates whether indeed that is possible. It doesn't need to go to an extreme degree, say 600V max. The larger RF tube projects I'd still break down and buy a transformer that would give me dedicated output voltage for my needs.
Does anyone have any ideas? I've tried googling this, but information on builds of this type seems pretty scarce.