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Topic: Arduino + Vacuum Tubes as a transistor (Read 705 times) previous topic - next topic


Good day!

I've recently finished a "Mad Scientists Lamp" (http://www.instructables.com/id/Mad-Scientists-Light/) that uses 3 25W incandescents and an off-the-shelf dimmer.  Yep, it's pretty cool, but I have that dimmer turned way, way down, so it's only putting out about the same amount of light as a candle (<2VAC).

What I want to do now is introduce some random flickering, and was going to do so with an arduino and some clever programming, such as adjusting the duty cycle of a digital out to control the brightness.

1.  I can't seem to work out why 10VDC barely lights the light, yet 2VAC (so says my fluke) lights it much brighter. Even if RMS is taken into account, I can't figure it out why 10VDC is so dim.

2. Obviously, I can't drive 3 lights with the arduino, so I was going to use a transistor driven by a digital out to "blink" the 120VAC to control brightness.  It's been, perhaps 10 years since I've messed with transistors, but it IS possible to choose a high-power transistor, and drive it with the output of the arduino, yeah?

3.  Being all retro-looking in the first place, why not use a vacuum tube instead of a transistor, for the same effect. But, since arduino is digital, the vacuum tube would be acting like a relay, which has limited life.  Should I perhaps look into preamp tubes, like they use in guitar amps?  I've got no vacuum tube experience, i just think it'd be neat.

The bulbs in question are 25W tall bulbs they sell at home depot.

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