Hi, I'm looking for eagle files for and adjustable lm317/337 power supply... I built one last night but the positive rail is wacky....
I can basicaly get 4V out of it, and if I turn the pot any further it jumps to the full 28V input voltage...
I can basicaly get 4V out of it, and if I turn the pot any further it jumps to the full 28V input voltage...
I had the same problem only with LM317 variable power supply...
Check if the pot is OK... I hah damaged pot...
There is also good to put 1/2W pot
Greeting,
Toni
Check if the pot is OK... I hah damaged pot...
There is also good to put 1/2W pot
Greeting,
Toni
allready swapped pots, and regulator itself... will try to swap caps later.. or maybe start by removing all of them... and putting them back one at a time...
WOULD REALY APPRECIATE A PCB FILE !
WOULD REALY APPRECIATE A PCB FILE !
Ok, it must have been the pots... eventualy swapped with a 1W 3k3 resistor, and its pumping out 18.5V now, which I can live with... target was 15- 20 volt...
Thats pretty close to what I settled on...
Waiting for some better quality phillips caps from the UK... So I may still remove a few, but these have been added one at a time with proper listenig using headphones.... life would be so much better with a scope, but your ears are pretty usefull too...
Waiting for some better quality phillips caps from the UK... So I may still remove a few, but these have been added one at a time with proper listenig using headphones.... life would be so much better with a scope, but your ears are pretty usefull too...
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Hi Nordic,
you have omitted the decoupling caps on the regulator pins.
The circuit could oscillate without them and similar control problems may ensue.
you have omitted the decoupling caps on the regulator pins.
The circuit could oscillate without them and similar control problems may ensue.
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