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Hi everyone,
Quick question: can we use a rheostat on our 5v 200a DC Power supply? We're doing electroforming and would like to start our acid copper baths at 2V before we put a piece in the tank, and then turn it up to 5V once the piece is fully submerged.
Can we regulate the powersupply with a rheostat? If yes, is there anything in particular we should be aware of? If we can't use a rheostat, any recommendations?

We're using a Powertec Multimod DC power supply - " Powertec 6M5-CCA-17-S101C 269-100051-001 "

Let me know if you need any other info.

Thanks!
 

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I wouldn't. To control 1000W from 0-5VDC at 200A, you are looking at 0.025ohms of resistance max, and 200A running through a wire wound resistor is not something I would want to do. It will end up likely having to be big to avoid having things catch on fire.

It will not be an off-the-shelf device either, someone will have to make it for you, like these people: http://mf-powerresistor.com/rheostat.htm

I would look for something like a variable voltage DC power supply built for that purpose, they use them on anodizing systems.

http://www.apdcpowersupply.com/products/
 

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Hi everyone,
Quick question: can we use a rheostat on our 5v 200a DC Power supply? We're doing electroforming and would like to start our acid copper baths at 2V before we put a piece in the tank, and then turn it up to 5V once the piece is fully submerged.
Can we regulate the powersupply with a rheostat? If yes, is there anything in particular we should be aware of? If we can't use a rheostat, any recommendations?

We're using a Powertec Multimod DC power supply - " Powertec 6M5-CCA-17-S101C 269-100051-001 "

Let me know if you need any other info.

Thanks!
Of course not !

200A Thru a rheostat ?

Remember it takes less than 100A to weld metal,

So what do you think 200A would do ?

Unless you can find a rheostat rated at 1000w safely.

Radio shack definitly won't have one.

You would need to put some form of dimer on the primary side of your
power supply, assuming that it's even dimer compatable.

A variac may work to some extent, depending on how the power supply works, if it's just a standard supply using a tranny and rectifier
then it will work, BUT if it's some form of switch mode supply, then
it will NOT work.

Sorry man ! not so easy !
 

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You could do this, but it is a bit old-fashioned. Your rheostat needs to be capable of 200A which is going to make it quite big, heavy and expensive. It will also run quite warm and waste quite a bit of energy.
A more modern approach would be to use a switchmode buck converter. This would allow the same control with minimal losses and may actually cost less than that big rheostat. This may take a bit of finding, 200A buck converters are not that thick on the ground, but you should be able to find one somewhere.
 

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Where I work we use 12volt \ 300amp rectifier's made by Rapid Electric. They have 240 volt input to a variable transformer (Powerstat) which feeds to a 240x12 volt transformer then is fed to the diode and capacitor banks. We use the reverse of plating for cleaning steel wire. The output is adjustable from 0 to 12 volts by turning the powerstat dial on the input. They work out very well for us.
 

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Awesome - we'll look in to that CyberKnight - thanks for your help!
Here is there name and address:
RAPID POWER TECHNOLOGIES INC.
18 Old Graysbridge Rd
06804 Brookfield , United States
Tel: View phone number
Fax: +1 203 775-0666 (FPS)

Glad to help ya.
 
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