Author Topic: Broken Variac - Fixable??  (Read 1407 times)

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Offline Gregg

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Re: Broken Variac - Fixable??
« Reply #25 on: June 15, 2018, 01:01:17 pm »
 :-+Congratulations, it looks like a reasonable repair.  Just don't snag the loops of wire as you take it off or put it on your bench.  Some of the old school variacs had nice perforated metal surrounds to protect them from damage; maybe another project in the offing to test your skills. ;)

Online Ian.M

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Re: Broken Variac - Fixable??
« Reply #26 on: June 15, 2018, 03:21:31 pm »
That would be quite a bit of work.   Its a pure open frame panel mount one, so unless you have a suitable enclosure you can mount it shaft up in, at the very least its going to need a back plate connected to the front plate with four thick walled pillars and massive bolts or studding so it doesn't rest on the rotor or winding before you even consider how to wrap it in metal mesh.   Then you've got to make a scale for it and find or make a pointer knob for that shaft size, and the knob's got to be very well fitted to the shaft as the inertial and shock loads when the rotor hits its end stops can be quite high.   

If I had that set sitting on my bench I'd concentrate on getting the big one set up for general bench use. Its going to need a  terminal cover and preferably a voltmeter, ammeter, circuit breaker,  voltage selection switch (so you can use it as 115V in 0-270V or 0-135V), IEC C13/C14 output and input connectors and a load power switch.  It could also do with a pair of lifting handles and some rubber feet, as I bet its a heavy brute.

For a weight comparison with the 3A one, you don't need to fully strip it down though you should probably remove the knob.   Just measure the case metal thickness and measure dimensions to calculate the total area (allowing for flanges etc.) and check with a magnet if its steel or aluminium, then look up the density and calculate the mass of the case and subtract it from the total measured weight.  It will be near enough. 

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