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Build a Pocket Ionizing Radiation Detector (PIRD)

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Step 3: Making a High Voltage DC Power Supply

Picture of Making a High Voltage DC Power Supply
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A high voltage DC power supply can be created from a disposable camera. First, take out the big black capacitor. Take out the smaller capacitor near it and place it where the bigger capacitor used to be. This will be used as a "filter capacitor." Take off all the unnecessary odds and ends (the xenon flash tube, the battery contacts, etc.) refer to the before and after photographs. I added a potentiometer to adjust the output voltage, but this is not necessary (that's the blue thing, don't worry about it). Make sure that if your camera had a "charge" button, solder the two contacts for the button together so that the unit is always in "charge" mode.

Be careful! The output from this unit will be around 400-600v! Test it out by touching two AA batteries to the + and - spots that were taken out, and the red LED should be on (or whatever other light is there).
 
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redox6021 year ago
How should a potentiometer be soldered into the circuit in order to adjust the voltage output? With one AA battery, I'm getting 360V, and with two AA batteries, I'm getting 650V. I'd like to be right around 400.
kelseymh2 years ago
That is a really awesome I'ble! I wish I had seen it before Randy, so I could get the glory of Featuring it :-)

I had a bit of trouble following the pictures and descriptions -- you might consider using the "image notes" to identify exactly where in each picture we should focus.

One comment about your "ambient air" G-M counter. You note that when properly aligned, the counter should discharge every minute or two. That's consistent with sea-level cosmic ray rates in the Northern Hemisphere. I wonder if you could get a more quantitative calibration using an Am-241 source scavenged from a smoke detector?