Messin' With Sasquatch

Sasquatch here being wall-plug (mains) electricity

The initial inquiry at work was innocent enough, I think — a colleague asked what the voltage limit of a BNC connector is. Wikipedia (linking back through a vendor’s spec sheet) says 500 V, and one also has to worry about the coaxial cable, which was the discussion until another colleague popped out of an office with “Two-and-a-half kiloVolts”. Complete with a description of the apparatus where that appeared in the experiment.

That led into a discussion of some of the crazy things we had done in the lab when we occasionally (or not so occasionally) didn’t have a strong grasp of what was going on. Two of the items that came up (and I had heard the story before, but it had been a few years) were The Cord of Death™, and Son of the Cord of Death™.

The Cord of Death™ sounds scary enough: it was a standard 3-prong power plug, i.e. with a ground pin (NEMA 5-15) … on both ends. Which is not advisable under almost any conditions. Apparently it was used to power a power strip whose power cord connection was bad and could not be fixed, but the rest of the strip was fine. And since all of the connections are in parallel, if you supply power to any outlet in it, the rest will have the juice. And in a grad school situation, I can see how such a kludge would be done instead of spending money on a new power strip.

The Son of the Cord of Death™ was a power cord, with the ground pin snipped off, and a BNC connector on the far end. I’m sure there are several applications for a connection where you want and AC signal at 60 Hz and around 120V, so why not skip the middle-man and avoid a power supply that’s just going to give you what the mains is supplying (oh, safety. Well, there is that, I suppose…)

All reminiscent of connecting two forks or metal rods onto a power cord to cook a hot dog or make a pickle glow.

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I didn’t have any contributions quite so reckless. I blew several things up in the lab in grad school — I don’t think any of our laser diodes died of old age — but I stayed away from deliberately messing with wall socket electricity as much as possible.

4 thoughts on “Messin' With Sasquatch

  1. Since my father is an Electrician by trade, I learned early on not to play around with the wall sockets. It still didn’t stop me, at the ripe old age of four, from figuring out the the tines on a fork might just fit inside them.

    When I woke up several minutes later I had a much firmer grasp of my father’s point about not messing with the wall sockets.

    He still takes great delight in telling that story.

  2. Open a coax cable. Shelding, insulation, hollow cylindrical conductor; a polyethylene foam core (low dielectric constant), central copper wire. Insertion of the central wire into the foam cylinder is facilitated by a slit down the entire length of said foam. A particularly naughty spark… All the fun is in the footnotes.

  3. When I was in 7th grade, I tried to make a model of an electric motor for a science fair project from plans I found in a book. It used a 6v lantern battery for its power.

    Upon completion, I wired it up and gave the rotors a couple of spins, but to no avail, it wouldn’t keep running.

    I thought I could solve the problem if I had some more juice. As luck would have it, I found an old power cord, and having not yet learned neither the difference between AC and DC nor the inadvisability of hooking 120v to something designed for 12v, I wired it to my motor and plugged it in.

    Nothing happened at first, so I gave it a spin to get it started. It made a few turns, giving off sparks, and then, predictably, the lights went out as it blew a fuse.

    This in turn, resulted in a stern lecture from my father.

  4. At 6-7 years old I opened a clock and reversed the wires inside to see if it would run backwards when I plugged it in. Somehow I wired a short and the wall receptacle emitted a large spark and turned black as the fuse blew. Dad soon made sure I understood that I was not ready to begin experimenting with electricity yet.

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