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Adrian Tuddenham[_2_] Adrian Tuddenham[_2_] is offline
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Default Minifon P55 wire recorder , pocket size of mid 1950s

N_Cook wrote:

Adrian Tuddenham wrote in message
valid.invalid...
N_Cook wrote:

[...]

I'm starting to find differences from this schematic
http://vintage-technics.ru/Minifon%2...nned-P55-1.JPG
orientation of triple ganged master switch is different
I cannot find the fast acting switch parallel to the seriesed end or

reel
switches


The first place I would look is around the operating key bank. I assume
it momentarily by-passes the end-of-spool switches, so it is probably
operated from one end of the slide locking bar on the key bank.

Have you tried following the end-of-spool wires back from the deck plate
onto the amplifier board (if they haven't fallen off yet) ? They might
lead you to it.



I can see why the 2 end of reel switches are in series but not why that
"switch" is in parallel with another one , the fast acting one, as it will
do nothing unless at the end of reel , which has to act before the fast one
, so what is the point?


I haven't got the machine in front of me, but my guess is:

At end of reel, the motor is disconnected and then cannot run either
way. Pressing a button will operate the slide bar and momentarily
re-connect the motor for long enough to get the wire moving and re-close
the limit switch circuit.

It could have been done much more elaborately, so that each direction
button operated in association with the appropriate limit switch; but
that would have involved more wires from the deck to the chassis and
extra switches on the button bank.


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