voltage regulators

Hey guys, does anyone know of a direct replacement for lm317 and lm337 that can handle a little more current? if not, can't they just be parralled for more current? thanks, frank

I think the LM338 for the positive side goes up to 5A.

I used 3A LM350, not sure if there is negative pair.

Nele said:

I think the LM338 for the positive side goes up to 5A.

Click to expand...

You can use the LM338k or LM350 in the negative rail as well.  This is what AMEK do in their PSU's.  If for example you wanted + & - 24v you would  make 2 seperate PSU's that were both 24v.  You then connect the 24v rail of one PSU to the 0v rail of the other, which becomes your 0v rail of the bipolar supply. The other 2 rails are then + & - 24v with respect to this rail.  I ripped off the AMEK circuit for my desk & it works very well.

One other thing.  You need to be rather careful if you are aiming to draw 5A from an LM338k.  The more the LM338k is dropping voltage across it the less the amount of current it will deliver.  It will only do 5A if it is approaching the minimum volts across it to get it regulating.  Look at the data sheet, to know whether you're in spec & bolt it to a good heatsink !!