Low voltage DC power supply 5kW 6

[alansimpson]

I need a variable DC power supply (0-100 V) to supply about 100 amps for some experiments. I have looked around and most seem sophisticated and expensive (over 5k)

Anybody know of cheaper solution or is this only to be expected at this power level?

Was messing around with car batteries and large resistors to control current. Cant find a rheostat big enough.

I have 3 phase.

thanks.

 

[jimbofitz]

Not sure about Lambda supplying 100Amps at 100V but we have 300Amp DC supplies of theirs in house.

Please clarify, your subject says 5 kW but your application says 100V @ 100A which is 10 kW.

Some of the extra expenses seen will be related to regulation and ripple of the output, which is also unknown.

 

[VEBill]

Maybe a welder?

It depends what you're up to. Especially the stability, precision and adjustability requirements.

Also, do you need adjustable voltage? Or adjustable current?

 

[alansimpson]

Thanks for help. I figured we will probably be working at 50 V but I put in a bit of flexibility up to 100 V. Probably not required.

Current is the most important issue so current controlled would be preferable.

As far as stability goes we will have to see.

Thanks again

 

[itsmoked]

Was messing around with car batteries and large resistors to control current. Cant find a rheostat big enough.

Why not use a saltwater rheostat? Nothing cheaper and they run up to megawatt ratings.(sealed dumpsters)

Use two metal plates facing each other in a container. Add salt. The distance between the plates controls the current.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ruggedscot]

The salt water rehostat is pretty funky - If you are playing with DC then you will get some hydrogen from one of the electrodes, and then if you were to create a spark, yep one almighty pop ! and a poop in your trousers.....

 

[IRstuff]

There's a default search for "high current power supply" no Dogpile

http://www.bruker.com/current_regulated_ps.html

http://www.us.tdk-lambda.com/hp/product_html/esspower.htm

TTFN

FAQ731-376

 

[ScottyUK]

There are some really big HP power supplies on the surplus market and ebay. Definitely worth a look.


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If we learn from our mistakes I'm getting a great education!

 

[ozmosis]

Try this company:

http://www.sprint-electric.com/products.php

used to be quite a simple basic DC drive but now gone all digital but still pretty basic stuff.

 

[ScottyUK]

Have a look on the US ebay site for item 220474815684, an HP 6475C power supply. 110V DC at 100A with normal features like current limit and good regulation, and just under half the price you are quoting.


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If we learn from our mistakes I'm getting a great education!

 

[OperaHouse]

There are a lot of 7.5V supplies on ebay with a lot of current cheap on ebay. Popular in the days of TTL but no one wants them any more. The supply can be stacked in series with batteries or crude unregulated supplies to get the voltage you want. Sounds like an anodizing application.

 

[waross]

You could try an old automotive 100A or 140 A alternator.
You can do a ratio between the engine RPM that the alternator starts charging at to the maximum engine RPM. The alternator will put out about that ratio times 14 to 15 Volts.
Example, The alternator starts charging at 800 RPM, maximum RPM is 5600 RPM. The ratio is 5600/800 = 7. Expect about 7 x 15 Volts or 105 Volts at that speed. (Make allowance for the ratio of engine speed to alternator speed.)
You can control the output with a small field current.
If you need more voltage, change pulleys and spin it faster.
You won't get something for nothing. The drive motor must be powerful enough to supply the energy that you want to develop.

Bill
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"Why not the best?"
Jimmy Carter