> I've got this ship's clock (Wempe Chronometerwerke) to fix. The
> PSU had a hissy (literally) fit and has taken out a few components.
> Now I have to decide on the extent of the repairs. The ship is on
> a world trip and is out of port temporarily until the 30th, when it
> returns and then continues its voyage, so whatever I decide has
> to be doable in a fortnight


Can you provide a fuller spec of what the chronometer "black box"
outputs/inputs are?

IF the output of this device is well defined I would be EXTREMELY tempted to
replace the main works with something else. The very large number of
boards/ICs for what sounds like a simple function suggests it may do more
than is apparent (even with TTL level ICs involved).

A PIC would do a timekeeping and solenoid driver job with ease but timing
accuracy would need care. Is this the ship's primary time reference or would
it be acceptable to correct it manually occasionally.

Any old PC laptop (or most any other sort of laptop) would probably meet the
need with a solenoid driver via the printer port. Adding a temperature
sensor (if the location is not of fixed temperature) would allow you to
temperature compensate the timekeeping.
This solution has the advantage of being replaceable with other equipment.
(I may be able to supply a 386 based laptop if desired).

Even HCT doesn't like 14 volt supplies - a suitably grunty crowbar zener and
fuse may be in order if you repair the existing gear.

Pace desolderer will take IC's out of DS boards with moderate ease. Discuss
offlist if needs be.




        Russell McMahon

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu