A Simple, Valve Curve Plotter

[pwdrive]

What happens when the HT suffers a momentary short? Yes, you've guessed, new LM317 time. Floating a regulator is really only for very controlled environments, not the relative rough and tumble of valve testing.

That's why I like valves, they recover better, the variable HT PSU that I have is a valve one I cobbled up with various bits, it's had a few wars but still works ok.

Lawrence.