Neon bulb display tansformers

Hello!

If I wanted to build a digital display out of neon bulbs, would I require a separate transformer for every display element?

Switching very high voltage is tricky and expensive, so that’s probably the cheapest way.

Maybe you could instead control a shutter in front of segments of one always-on neon tube?

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Hi, you can use transistors with a high switching voltage (70Volt). See here an example they use for a clock display http://www.bowdenshobbycircuits.info/page7.htm

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Oh, I was thinking about neon tubes which have secondary voltages at 1kV or higher, imagining each segment as a separate neon tube. You are right, I missed the “bulbs” part of the question. 70V is a lot easier than a few kV! Thanks @pauldg123 for catching that.

The “12 Stage Neon Sequencer (NE-2 / NE-51)” project there looks like a great example, including the boost converter for a 70V supply. @arcadeperct — that would avoid the need for a transformer at all. It looks like PNP transistors with the required C/E voltage rating are less than $1 per transistor. Mouser shows the 400V-rated STX93003 for $0.44 quantity one; Arrow shows $0.15 quantity one. If you use multiple bulbs per segment, you’ll only need one transistor per segment, not per bulb, as they draw very little current. (Also note that if you do this and still use a transformer instead of a DC power supply as shown in that project, you’ll need to rectify the AC into DC.)