Supply for valve equipment

[medical-nerd]

Hiya

I've just obtained a valve power supply giving approx 300V DC plus heater output. I want to use this as the supply for a 'valve breadboard' where I will be building valve receivers using subminiature valves such as the DC70 and more normal valves.
I want to supply a range of voltages : 300V, 150V, 100V, 50V depending on the design.

What would be the easiest way to do this - is a simple resistive divider the best choice??

Cheers

Steve

[Gyro]

This circuit is fairly ubiquitous... https://www.elcircuit.com/2012/07/0-300v-variable-high-voltage-power.html

It's performance isn't great (it uses the incoming 300V rail as it's reference) but it is cheap to implement and does have rudimentary current limiting (at the risk of cooking the Mosfet). It ought to be good enough for basic dropping of the HT rail voltage for low current use though.

[Jwillis]

Aside from the filament  the rest of the valve doesn't require a whole lot of amps. The DC70 uses around 200mA at 1.25 V for the filament but the rest will at most take 25mA at 150V  .You could simply get some medium amp zeners . Just series them to get the appropriate voltages between each zener. I did this to make a supply for a tube radio and its still works great. Something similar to the circuit below.The value of the zeners can be any combination you need .