Question about LM317

[bogdan2013]

I have an adjustable power supply with LM317 . I can increase the maximum current by putting in parallel more LM317 ?

[Simon]

No, You will need to use one or more parallel transistors, look around the net and you will find a schematic no doubt, or check the datasheet of the LM317 and it may have some hints, this is a common technique to get higher currents from the same regulator particularly when more current that the package could physically handle anyway.

[bogdan2013]

I found something :
http://www.reuk.co.uk/OtherImages/lm317t-pnp-pass-transistor-voltage-regulator.jpg

[Paul Moir]

That's the idea. 

If you're still in the design phase, you might think about something like the ancient LM723, which has a wimpy pass transistor but is pretty easily setup for external ones.  Plus current limiting is simple.

Have a look at:
http://www.thebackshed.com/forum/forum_posts.asp?TID=2249&PN=2&TPN=1

[mariush]

See  http://www.ti.com/lit/ds/symlink/lm117.pdf  (it's same datasheet for lm117 and lm317)

Typical Applications, page 17-25, you have several designs that all do more current than a single lm317.

[bogdan2013]

@Paul

Is a old PSU and I want to modify it .