Can you ID this voltage regulator ?

[simonfraser]

It's the item at the bottom with the burn marks, 12V supply.

And is it feasible to replace it ?

My soldering skills are good.

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[rogerthebodger]

It's the item at the bottom with the burn marks, 12V supply.

And is it feasible to replace it ?

My soldering skills are good.

[/URL]

It looks like this but you will need to read the printed markings to determine the exact spec as this package seems to be available in various fixed volttages and variable as in my link

http://www.hobbytronics.co.uk/lm1117-voltage-regulator

 

[A_8]

You need the printed markings to know what it is and a lot of them look the same. I do think its a fixed regulator as there are no configure resistors around it.
Anyways they usually dont break unless something breakes them and from the pic it seems to have been overloaded so even if you find the right part it might just burn up again as the problem is in whatever the regulator is suppling power to.

 

[simonfraser]

ok, numpty here connected the power the wrong way round for too long, display not working
when i eventually figured out what i had done i reversed the connection and it immediately went bang !

is this worth a fix, or junk it ?

 

[Lon nan Gruagach]

ok, numpty here connected the power the wrong way round for too long, display not working
when i eventually figured out what i had done i reversed the connection and it immediately went bang !

is this worth a fix, or junk it ?

Depends what it is really.

There is a chance that power the wrong way made one of the components go short, which when you corrected the power blew the regulator.

If you had a bench power supply then the way to go would be use that instead of the regulator with a cautious current limit on it.

See if you can get a better pic of the bit missing the magic smoke.

 

[simonfraser]

tnx,

'If you had a bench power supply then the way to go would be use that instead of the regulator with a cautious current limit on it.'

thats interesting.

they have just offered me a good fix so as dont have a way to limit the current from my power supply i shall spend some more money instead, cant win them all.


could i have grounded / zeroed the shorted component and avoided the blown regulator ?

 

[Lon nan Gruagach]

could i have grounded / zeroed the shorted component and avoided the blown regulator ?

Only if you knew that it had gone faulty that way. Its not always obvious with semiconductors.
Consider a transistor that is in some ways 2 diodes facing each other. If reverse power shorts 1 diode, then the other will still block a shorted power supply. Then correct the power and you now have a conducting diode across the supply rails... you then throw the dice to see which goes first, the remainder of the transistor or the power supply.