# L.W. Chuck Co power supply



## Rick Berk (Mar 30, 2013)

I was just given a L.W. Chuck Co. magnetic chuck 6X18. I have wire wheeled it clean of rust and paint. The person who gave it to me said it had been sitting on a shelf for 35 years that he knew of and did not know anything about its condition. My question is can I buy a bridge rectifier from Radio Shack, put 120 VAC in and get 110 VDC out. The tag on the side of it said 110VDC. Any suggestions will help me as I have never used a magnetic chuck or vise. The current draw is listed a 1 amp. The power supplies I have found on ebay are well out of the range I want to spend on this possible boat anchor.  Thanks.


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## Tony Wells (Mar 30, 2013)

The short answer is no. The resultant voltage would not be 110, although it would be a rough DC (with some AC superimposed on it). You want to add capacitors for filtering, and a voltage regulator to control the output. It won't be hard to build a power supply. Google is your friend. Here's a basic explanation of how AC to DC power supplies work:

http://www.electronics-tutorials.ws/diode/diode_6.html

Without a regulator, the voltage will actually be higher than your input, if I remember right, input x 1.414


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## Rick Berk (Mar 30, 2013)

Thanks Tony, Ill keep searching, Although I wired my own house electricy has always been magic to me. I have never studied this subject or never had any friends that could help me with it.


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## Tony Wells (Mar 30, 2013)

Simplest way would be a variac and a bridge. That way you could run the input voltage down to where the output would be what you needed. 1 amp, you say? Sure about that?


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## Rick Berk (Mar 31, 2013)

Thanks Tony you just said the magic word, I have a variac that has been on my shelf for 25 years and I never knew what to do with it, I'll get it dug out monday then head to Radio Shack for a full wave rectifier. I'll also check but I thought I read on the tag 1.0amp  do you suspect that it is 10 amp? I can't find anything on the internet about LW chuck co. other than other people have them with no power supplies also.


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## Tony Wells (Mar 31, 2013)

No, I don't think it would be 10 amp. 1 amp is probably about right. One thing I might mention is that many original power supplies for mag chucks have a de-mag function where AC voltage is fed to the coils for a few seconds to help remove residual magnetism in the part. You hit that button and while it is buzzing, remove the part slowly away from the chuck. You might later want to add that feature.

You should fuse this thing, though. Try a 2 amp slo-blow. Make sure your Variac is heavy enough to handle the load, and once you dial in the voltage, use a switch to control it. Leave it set. If you run it down in voltage, the current draw will climb rapidly. Not good for the Variac.


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