23-04-2012, 04:34 AM
I'll double-check when I get up but I'm sure that T3 was a AC127.
As for testing them, I've done it with an LED and a couple of resistors. Two of them light the LED with their bases disconnected, ie are short circuit collector to emitter, and the other doesn't light it at all.
I don't know how they can have blown either; I'd have expected the BC108 to go first. Maybe one was faulty before I started?
I thought that BC227/BC237s should be OK as they can stand 800mA and are getting less than that. Why the sods are getting warm is something that needs looking into.
As for the current limited PSU how about this:-
I've got all the bits, apart from the FETs but am not bothered about being able to go right down to 0V. One point: what should RSC be?
To be honest I didn't realise that what I was doing to that audio board was dangerous.
Thanks for the support
Joe
As for testing them, I've done it with an LED and a couple of resistors. Two of them light the LED with their bases disconnected, ie are short circuit collector to emitter, and the other doesn't light it at all.
I don't know how they can have blown either; I'd have expected the BC108 to go first. Maybe one was faulty before I started?
I thought that BC227/BC237s should be OK as they can stand 800mA and are getting less than that. Why the sods are getting warm is something that needs looking into.
As for the current limited PSU how about this:-
I've got all the bits, apart from the FETs but am not bothered about being able to go right down to 0V. One point: what should RSC be?
To be honest I didn't realise that what I was doing to that audio board was dangerous.
Thanks for the support
Joe
