Thursday, January 17, 2008


Today Richard demonstrated he can't even blow up a capacitor properly.

"We're going to blow up a capacitor, want to watch?"

Now, anyone else would ask "why?" at this point, but experience suggests that I wouldn't like the answer, so after due consideration I downed tools and followed him. A very alert observer might have noticed the pause.

In his room he'd already attached wires to the capacitor, which was potted inside a box as part of some device or other. I suppose the idea was to see how safe the device was if this capacitor ever decided to explode in normal use, but as I say, I didn't ask.

A power supply was attached, connected backwards across the poor cap and switched on. Cue rapid exit from room... The power supply quickly ramped up to about 4 volts and about 3 amps.

"Twelve watts? It's not going to last long" I opined, from the doorway.

"About... now, I'd expect" I ventured, after several seconds had passed with no visible result.

"Any time now..."


After about a minute at 12W I wandered in and wound up the supply up to full power, which was about 20W. People started to cower...

A minute or so passes, with nothing visible happening.

"Twenty watts? I don't believe it..."

I wander over to the device and feel it - it's distinctly warm... No smoke, but I do start to smell a rat - "You did disconnect the cap from the rest of the circuit, didn't you?"


Gah... Bloody capacitor's probably laughing itself silly while the rest of the circuit dumps all the power.


  1. "You wrote about me in your blog? I might sue you for deformation"

    "If you'd managed to deform the bloody thing I wouldn't have mentioned it..."

  2. He managed to blow it up the next day, it went "pffft" quietly after a few seconds and there was a small release of smoke. Hardly worth mentioning.

    Gah. In my day when we blew up a capacitor there'd be blood, holes in the ceiling and ringing ears...