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What am i doing wrong?

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Bluechip:
Some LM317T chips need a MINIMUM load of 10 - 15mA to regulate correctly. ( Been there !! )

Also,

First Diag: The diode above the LM338 is wrong. It don't seem to do anything ??

See att.

shipto:
I think during normal operation it doesn't I believe its there in case the cap somehow manages to discharge through that line.
dont ask me how I am guessing.

Because I am still struggling the circuit seems absolutely fine until I try to put a cap on the voltage out line then even with diodes it makes the 317 go pop, lucky I have so many but I dont really want to blow any more if i can help it.
Heres the rub I tried to remove caps from the 5v line and thats fine except the infrared driver goes haywire without any  :bang:
although I currently have the driver working from a seperate power source maybe it will be fine if I connect it as it needs to be?

Bluechip:
If the capacitor on the output is charged up ( would be anyway ) and say the input got disconnected. The output would then be +ve of the input. This is back to front. Most regulators will not like this and promptly perish. If it happens, D1 will conduct and connect the input to the output, ( less some 0.6V, the volt drop across D1 ), this is relatively harmless and the chip will survive.

There does not seem to be any DC path on the cct. you first posted from the output, through R1, adj. terminal, and R2 to deck as shown in the diag. I got from the LM338 data sheet. It's not marked on your diag. but it could be the attempt at D2 on the one I posted ???

It looks to be the wrong way round ???

Check the differences between the two LM338 diagrams ??

Where did you get yours from ??

shipto:
from google images some have c2 some dont but I think i see what your saying c2 may need to be there.
I am going to a friends his daughter in law has qualifications maybe she can help me.

shipto:
Went back to drawing board and I think (no fingers crossed emoticon?) I have it, rather than trying to run the 5V of the 24V line I thought what if I ran them both from the feed line. So I hooked a 12V supply to the breadboard along with 2 lm317's and got the result in the picture.
No dancing banana dont want to jinx it.

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