Tuesday, March 30, 2010

Right Tool

I've been making another lab bench recently for a new project. Got a good, strong table from the used furniture store. Covered it with anti-static mat, and finally I found some "shelves" at Homeplus. Actually, they are small, cheap (low-quality) student's computer desks - but they are plenty strong for my purposes. As I was assembling them this morning (some assembly required), I noticed that my screwdriver was EXACTLY the same tool as shown on the instructions.

I know, I'm an engineer, and never read instructions. I wasn't actually reading them, I just happened to notice the picture of the screwdriver as I was about to throw away the instructions! Here is the finished product:

EDIT 1: I needed to show the clean lab bench, because in just a few weeks time, it will end up looking like this:

Well, that's not entirely fair, this photo was taken on a really messy day for the lab bench - usually is isn't quite so cluttered.

Finally, I am quite proud of myself for solving a problem. It's a little difficult here in Korea to connect to the building's electrical ground. In the USA, our plugs and outlets both have a fairly easy way to connect to the earth ground. But in Korea, two factors work against me for this purpose. First, the ground connection isn't a prong and socket, but rather a springy "finger" which wipes against a small metal strip on the side of each power plug. It is not easy to connect to this (I've tried). Secondly, there are not many electrical outlets in a room. In the USA, it's relatively easy to connect to ground at the outlet, but in my office here the outlets are under the floor. Accordingly, everything is powered from plastic outlet strips. The first lab bench I connected to ground, I did it by taking apart the plastic power strip and soldering on a long ground wire to the internal ground bus. It was clumsy, and I didn't like the result very well.

This time, the outlet strips I got for the new lab bench didn't have screws. If I wanted to take them apart, I was going to have to break something. Therefore, I came up with my new idea. I bought two power plugs at the store. I then took them apart, removed the main power prongs for 220V (just to make it safer and clearly something special). That left just the grounding prongs. Now I can connect my lab bench to ground very easily - just screw the ground wire to this special plug, and then plug it into the outlet strip (The Stumbler says with a big,proud smile).

EDIT 2: My super grounding invention wasn't so super after all. Turns out the two main power prongs also provide the main force that holds the plug in the socket. Without these prongs, the plug is only held by the spring wipers of the ground, which isn't very strong. In the end, I just taped the plug to the socket using duct tape, which isn't very elegant.

EDIT 3: Why do we call it a lab bench? You don't sit on it. Several Korean friends were confused when I mentioned lab bench, and thought it was a kind of chair.

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