21 Sep
2014
21 Sep
'14
8:56 p.m.
How do DC OK circuits typically work?
Typcially a set of analogue comparators, such as sections of the LM339
chip. They detect if power rails are above some minimum threshold, or in
the the better types of PSU, if the power rails are within a certain
voltage range. Some PSUS check all pwoer rails (all have to be good for
DC OK to be asserted), others just check the main rails
Not asserting DC OK could I guess either be 'genuine' (one of the power
rails is missing) or 'false'(the DC OK circuit has failed).
-tony