Big Voltmeter (by alaric)
My mate Seth brought me back a lovely big AC voltmeter from India, where the power distribution systems tend to reflect an earlier, more exciting, time where things arced and crackled, and everything was made of Bakelite.
Anyway, it's meant to mount on a panel, and the rear of it just has two exposed screw terminals. So I had to do a bit of work to make it usable.
Firstly, I obtained some crimp terminals - a nice set with eighteen different kinds, including rings, spades (male and female), forks, and butt splices in three different sizes.
Anyway, I really wanted it for the ring terminals, which would securely attach to the screws on the back of the voltmeter. So upon returning to home, I went to Maplin and obtained a large enough box, then spent a pleasant hour or so in the workshop with my father in law drilling holes in the box so that I could mount the voltemeter on it. We also scraped away some paint from the inside of the mounting holes, exposing the bare metal, so that I could attach another ring crimp terminal to the mounting bolt as an earth connection. Better safe than sorry!
The end result is a nice box with the voltmeter mounted on it, with no exposed live metalwork, and a standard mains plug on the other end so it can monitor my mains voltage. This is a pretty useful tool, since we do get power cuts and brownouts and so on quite often out here, and the lights often change brightness at random...
As I write, it's reading a bit over 230v, while earlier, it was reading more like 225v. At some point I'll ask Sarah to turn the shower on (our biggest load) and we'll see how much the voltage drops - because I know the lights usually dim when the shower comes on 🙂
Building Maintenance, Electronics | alaric | 
Mon 1st Oct 2007 2:49 pm
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