LM317/LM338 2x 16850 voltage not enough?

[bakulaw]

Thanks for the replies. I checked my wiring again and I just found out that lm338 Tab is touching the heatsink, my ndb7875 diode is also on the same heatsink. Is the diodes housing(dunno what to call) connected to diodes circuit?

 

[Hiemal]

http://crfgsandiego.org/images/temp/10.gif

Nope, it isn't.

 

[The Lightning Stalker]

Enough charge on the capacitor can blow
away the bond wires and cause the diode to
go open circuit. I hope that is not the
case.

 

[bakulaw]

My lm338 is also damaged, its not regulating current, it killed my diode. Is there a way to make the current stop flowing when regulator is damaged? Is it ok to add fuse at the output?

 

[Hiemal]

just to be sure, you had it connected like this, yes?

http://diyaudioprojects.com/Technical/Current-Regulator/1-Amp-Current-Regulator-Scheamtic.png

and this is its pinout.

http://circuits.datasheetdir.com/39/LM338-pinout.jpg

AS far as making it stop if the regulator is damaged... It shouldn't be problematic once you replace the regulator and i'm kind of mystified how one of those could die unless you stuck it in a wall outlet or something. They're normally VERY robust.

 

[The Lightning Stalker]

My lm338 is also damaged, its not regulating current, it killed my diode. Is there a way to make the current stop flowing when regulator is damaged? Is it ok to add fuse at the output?

By the time a fuse blows, the damage has
already been done. There isn't really a
way without a significant increase in
complexity.

 

[bakulaw]

Hmmm. Are there fake lm338s/lm317? I bought this on ebay. I already damaged a few. lm338 cant give more than 1.8A, i thought it has thermal protection but mine sometimes die instantly. I think my wiring is correct since its working fine around 1A. Thanks all for your time.

 

[The Lightning Stalker]

Almost all are fake. Take a look.

http://laserpointerforums.com/f39/x-drive-x-boost-88589-2.html#post1303419
http://laserpointerforums.com/f67/lm317-driver-still-best-cheap-option-90086.html#post1310728

 

[bakulaw]

Almost all are fake. Take a look.

http://laserpointerforums.com/f39/x-drive-x-boost-88589-2.html#post1303419
http://laserpointerforums.com/f67/lm317-driver-still-best-cheap-option-90086.html#post1310728

I wish you're lying, i've a lot LOL. Thanks! I can stop trying to fix it now.