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.

The schematics and PCB layouts were created using Eagle and are available for download here.

Photo Gallery


Simple! Now explain to my wife what it is for...