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August 18, 2019, 02:35:48 PM

Author Topic: Costume props  (Read 240 times)

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Offline Bodger

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Costume props
« on: October 13, 2018, 10:26:00 AM »
I'm working on a cosplay prop using tubes I've salvaged from an old tv. Many of them will light up with a 12 ac power supply. I want to make this prop (a steam-fairy pistol) portabl but a pack of AAs is too dim.

Offline Paul Joppa

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Re: Costume props
« Reply #1 on: October 13, 2018, 12:46:20 PM »
Yes, you will need much larger cells and many of them to get enough voltage and current to light up a normal tube. They'll still be pretty dim unless you exceed their rated heater voltage by quite a bit.

Alkaline cells have a fair bit of internal resistance, sou you'll lose some voltage to the internal resistance - like .2 to .3 volts with a 12-v stack of C cells (never mind AAs, they are too small). More important, the voltage falls rapidly under high current, so the brightness will fade rapidly as the evening wears on unless you only fire them up for brief intervals with plenty of rest time in between.

Do you have any battery-operated power tools? Their rechargeable batteries will have a flatter discharge voltage curve.

If you have 7-pin or 9-pin "mini" tubes, you can probably rig up an LED in the center of a socket to light them up in your choice of color, with vastly smaller battery requirements...
Paul Joppa