Originally posted by: Bulldozer2003
I have a bunch of 1.5A rated LM317 positive voltage regulators. If I want to provide more than 1.5A, can I put two in parallel to provide up to 3A? Do i need any diodes or anything on them to do this?
Yes, and no.
The problem comes in when one wants to supply, say, 8.03V, and the other wants to supply 8.05V. The 8.03V one will do most of the work and then overheat and shut off. So simply hooking them up in parallel is not really a good idea.
But there may be a way around this. I would try the following (just as an experiment)
1) Put a small series resistor on the output pin of each regulator. One ohm or so should be OK. Just makse sure the resistors can handle the power.
2) After the 1-ohm resistor, tie the outputs together.
3) Give each voltage regulator its own feedback circuitry, but put an adjustable resistor (potentiometer) in each pack.
4) Crank up the amps with a load of some sort, and adjust so that each regulator drives the same current.
It still might not work, but this stands a chance of working.