Hello, a query about power supplies

[Sparky49]

Sorry, I presume one would control a grid voltage or something with a potentiometer.

I will look into producing a fixed power supply. Many thanks.

[Sparky49]

If someone could give me a suitable transformer number, I'd be very grateful.

I will find a rectifier which will suit it, although if you know of a combo which would work together, that would be great too.

Sorry to be a pain, but I'd like to know I'm not wasting money.

[Mooly]

Originally Posted by Sparky49

Sorry, I presume one would control a grid voltage or something with a potentiometer.

I will look into producing a fixed power supply. Many thanks.

Yes you would use a pot for that. To make a variable PSU that can supply a bit of current (which the pot can't) can be done easily. All you need is the basic unregulated supply (say 300 volt) and to add a high voltage high power series pass transistor (actually two to make a darlington) and feed the base from a pot. One resistor and one more transistor will add current limiting and protection.