11 Nov
2005
11 Nov
'05
7:53 p.m.
Douglas Taylor wrote:
What I don't have is circuit schematics that tell
me how to connect
power to these parts and what voltages, and how to cable the electronics
to the interferometer portion.
Any tips on how to efficiently reconstruct circuit diagrams from
inspection of the electronics? There are two cards, with standard TTL
and analog parts. The printed circuit has a design date of 1985, while
the IC's have 88-89 dates.
Well, you could start by tracing out the power pins from the chips, and
working out what they connect to. Obviously the TTL will want 5v
(possibly at quite a high current). The analogue supply voltages would
be more difficult, but have a look at the voltage ratings of power
decoupling capacitors - that will give you an "absolute maximum" idea.
The "real" voltage will probably be somewhat less.
Gordon.