HOWTO make a 4,000-volt infrared "snooperscope"


15 Responses to “HOWTO make a 4,000-volt infrared "snooperscope"”

  1. robuluz says:

    Those were the days. Pop out to the shed and blow the dust of your 4000V transformer, and look around for your old can of black airplane dope. Got yourself an infrared snooperscope, right there.

    You’d be positively thrilled with the rising number of home invasions!

  2. awjt says:

    That’s not all a girl can do with 4000 volts and a plastic tube.

  3. Antinous / Moderator says:

    For the time, money and effort invested in this, she probably could have installed a trapdoor and an alligator pit.

  4. monopole says:

    Actually the design is a converter tube which translates Near IR light to visible. The 4-6kV tube does not emit Near IR light, a filtered incandescent  lamp does that.

    Now $40 of plastic, CCD, and LED’s do the same thing:
    And incredibly well

    • peterkvt80 says:

      After the WWII there were lots of these IR scopes around. They didn’t need illumination. You could see people at night as fuzzy green images just from their body heat. Mine was completely sealed watertight so the high tension battery could not be changed. After a couple of years the image faded away to nothing.

  5. Nick Kukich says:

    Relax, Cory.  4000V is not particularly sensational.  A flyback transformer from a CRT assembly might put out in excess of 20kV.

    • Paul Renault says:

       Actually, getting 4,000 volts out of three D cells is pretty interesting.  Mind you, small electronic camera flashes have been doing this for a long time; disposable cameras’ flashes manage to get high voltages out of just one AA battery.

      And, like the flyback transformer, you treat these circuits, when live, with lots of respect.  And with one hand in your pocket.

    • The battery supply had a cap to story energy so was still hazardous despite being powered by batteries. BUT… the neon sign transformer is lethal and overkill. Would I power the tube with a neon sign transformer centimetres from my face and eyes….. not likely!!!!!!

    • whitcwa says:

      Yeah, every video camera with a CRT viewfinder has a multiple-kilovolt supply inches from your face. No headlines yet.

      • No,  but the internal impedance of the CRT supplies is considerably higher than the neon sign transformer. Meaning, the CRT supplies can only supply limited current, a neon sign transformer, depending on size can usually deliver 50 mA or more which is easily fatal.

  6. petz79 says:

    If there’s a person in your bedroom and you don’t already know, if it’s a friend or foe, I don’t think such a device is going to help you much.

  7. Eark_the_Bunny says:

    That sounds like a neat little gadget.  Use it to detect burglars and  then divert the 4,000 volts and ZAP them.

  8. Couldn’t a 4K Volt infra-red light double as a Hot Dog warmer?

Leave a Reply