17 Dec
2017
17 Dec
'17
6:23 a.m.
On 12/17/2017 08:24 AM, Peter Coghlan via cctalk wrote:
OUTPUT CROWBAR:
The common use is to create a hard short circuit across the output if
the output voltage
exceeds a safe limit.? The logic is that a power supply is cheap
compared to the rest
of the computer.? The typical output where this is done is the 5V rail.
The tester likely cannot test a triac its not a simple transistor or
diode.? They are easy to test
a light bulb (12V) and a DC source.
Allison
I have a
suspicion that this component may be faulty on the input side of my
H7826 PSU. A little tester I have does not recognise it, it is possible that
the currents it uses are too low for this particular triac, but I am not
sure.
What is the function of this triac in your power supply?
I have come across a triac which is used to switch between 115V and 230V input
in the PSU of a DEC 3000/300. My triac went short circuit which caused some
release of magic smoke when the PSU was used on 230V. I also had difficulty
finding a replacement for it so I ended up leaving it out. The PSU worked
fine on 230V only without it once I replaced the other damaged components.
If your triac has a different function, ignore the above.
Regards,
Peter Coghlan.