I am in need of a voltage regulator IC to be used as a constant current source. Max o/p between 5A to 10A.?

Question

Tried LM 317 but has low o/p current. Any comments on LM 338? What about the LM 78xx series? I am using a 12v, 5A i/p.

Answer 1

You can't get 12V 10Amp out of a power supply if you put only 12V 5Amp in.

Here is a description (with diagram) of how to make a 12V 10A power supply.

http://www.elecfree.com/circuit/power-su...

Answer 2

I will tell you one way of doing it.  You can figure out the details.  

First of all 5-10A is a lot of current!  Are you sure you know what you want?

One way to make a constant current source is to monitor the output current with a sensing resistor- usually very low ohms, but in your case with so much output current, very very low ohms.  As the voltage across the sensing resistor changes, the output source changes to make the voltage stay the same.  That means you have a constant current by making the voltage drop across a fixed resistor stay the same.

The implementation is not that hard, but with the amount of current you have to have, that will be the challenge.

You will have to have a high-current capacity transistor to pass the current necessary for this high power output.  You can use a low power opamp to handle the drive.

I know this is vague.  But in engineering we start of with the specs and go from there.