Monday, August 04, 2014

Fixing clocks

Fast on the heels of my success with the printer, I turned my attention to our non-working clock. It's a small brass carriage clock that was given to us when we got married 34 years ago. The only value it has is sentimental, and to be honest we're not that sentimental, so replacing wouldn't be an issue. However, every so often I get interested in why something has stopped working and how I might be able to fix it.

Maybe a year ago the clock started to have problems. A battery had failed and the negative battery connection had become corroded. I cleaned it up with a bit of emery paper and the clock worked again with a new battery. But the problem with corrosion is that it takes a lot of effort to clean up and once it's set in it doesn't easily go away. Eventually the clock failed again and I assumed that that was it. For over a month now it's been sitting in the lounge declaring the time to be 11:55, causing confusion and occasional panic!

So I decided it was time to explore, and I had a look at it. The terminal was indeed terminal. Corrosion had spread over the whole surface and there was little point attempting to clean it away in the ope of restarting the stopped clock. The question was: Did the mechanisms still work? Off the the man garage!

No doubt you've heard of the concept of the man-drawer, a place where men keep useless stuff that might come in useful one day. Well for some of a drawer is simply not enough space, we need a shed or even a garage! I have bits of things in boxes and crates. I have a large supply of screws, nuts, bolts, washers, hinges, plastic thingies form fitted kitchens and wardrobes stored away just in case a major incident occurs and one of the stability brackets from an Ikea bookcase is the ideal solution to the problem.

I dug around and found some flat town and earth cable from an old wiring project from years ago and stripped out a bit of copper wire. Using a fresh battery I bridged the connections and listened. The clock ticked. It was alive again! Next job was to remove the old negative terminal and come up with a solution. I twisted the copper wire into a spiral rather like the ones you see in the end of a torch or battery compartment and shaped the other end to make a connection with the circuit board. A bit of soldering and the job was done.

The clock is ticking, or at least it was when I left it half an hour ago. If it runs for a day I think I can declare it fixed. If it doesn't, it's still fixed, just not in a permanent fashion!

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