What's wrong with this LM350T circuit ? ( IC blown when shorted output )

[Pigi_102]

Hello all,
I've found a nice circuit around, for an LM350T variable power supply, and I built it.
Here the link:
https://www.eleccircuit.com/lm350-adjustable-voltage-regulator/
I added a second pot, as indicated in the linked page, for a precision settings, and thus the circuit become this one:

Everything was perfectly working ( voltage regulation and so on ) so basically I havn't made any (big ) mistake.
( In effect I did inverted values for C3 and C4 but it was working fine )

Reading trough the datasheet I've seen that the IC has short circuit protection so I tried to short the output ( I'm a bit disorded on my bench and sometimes it happen to me to have too much stuff on it and the output get shorted ) and immediatelly the LM350 blown.
Alle the diode were in correct position as per circuit and datasheet

Can someone help me in understanding why it blown ?

Thanks in advance

Pierluigi

 

[danadakk]

Dana,
thanks for taking the time to help me but what you ask is way over my capabilities.
I'm starting to think that what I'm asking is way far from my capabilities as beginner hobbiest, and should wait until I get more experienced to achieve this result.
Not to say that at 3,5 bucks at IC it could be expensive to do all tests
I'll keep informed if I can proceed.


Pierluigi

I am not advocating short circuit but a partial load step so you dont hose the LM350,
for tests purposes. And witness with a scope what LM350 terminal pin voltages are doing.
For clues.

Regards, Dana.