Nixie Tester

W sent me a nice thank you gift recently. A small box arrived in the mail from him loaded with a variety of nixie tubes to mess around with. Most of them appeared to be in good used condition with only a couple of them being partially burned out. Nixies were considered ‘failsafe’ because even when one of the numeral elements ceased to light you still knew whenever that number was to be displayed. Didn’t take a genius to figure that out. Thanks to W and one of the techs in our vintage instrument repair department at work I now have a nice little nixie tube collection. Problem is, I did not have an easy way to test any of them.

Typically nixie tubes light up around 170VDC to 200VDC. That’s a lot of juice to pump into them. None of my DC bench power supplies go anywhere near that high a voltage. I would have to spend some time building a custom device or rig up a power transformer to ignite these old tubes. In an email I asked W if he had any advice for building a basic nixie tester. He gave me some good suggestions. Then something very cool happened about one week later. I received another box in the mail from W. This time he sent me a home brewed nixie testing setup. It’s simple, and it works well. Man is it dangerous though.

Taking an old electrical power cord W cut off one end and stripped back the insulation. Then he soldered on a series of components that take 120VAC from a wall outlet and shifts it to 170VDC. W soldered on a nixie socket and left one wire terminated with an alligator clip. More often than not nixies were connected to circuit boards with sturdy sockets. Makes them easy to replace just like a light bulb when one of them completely burns out. You just pop a new one in. With this rig W built all I have to do is shove a nixie in, connect the alligator clip to any socket pin and plug the cord into a wall outlet. Because some of the wiring is exposed I came up with a procedure of plugging in the cord to a power strip with a big toggle switch. Making connections with one hand only I then turn the power strip on and the nixie lights up. Afterward I turn off the power and unplug the cord. Only then will I handle the tester.

170VDC is nothing to be messing around with. Got to take it seriously because that shit could hurt me real bad or kill me outright if I get zapped.

~ by factorypeasant on January 17, 2007.