Introduction
My first valve driven, variable speed dekatron spinner was a failure in that I used silcon rectifiers for the power supply. I failed to achive the goal of an all valve spinner. Mike Moorress has an all valve spinner but it is for 110V mains and I needed a design to work at 230V for the UK where I live. A trivial solution would be a step down transformer but...
I wanted to use EB91 (6AL5) double diodes as rectifiers (as I had a few in my junk box) and I did not want to abuse any of their ratings. So I evolved the design below using a small transformer, with two 6 volt secondaries, for the heater supplies and using the transformer primary to give me a centre-point about which I could arrange a negative doubler and a positive doubler, to give me the 550 volt potential I needed to use a GTE175M trigger tube to drive a GC10 dekatron...
And my thanks to Mike Moorress who gave me suggestions fo 230V operation and, of course, the original idea.
Schematic & PCB
Note that this circuit connects directly to the mains and has potentially fatal voltages present. The capacitors will retain a charge after the circuit has been disconnected from the mains. Please take care.
You should look in the "/Dekatron Projects/All Toob Dekatron Spinner 2" folder.
Photo Gallery
Simple! Now explain to my wife what it is for...