Teledyne Gurney DRO
Posted by
abenedro
on 2003-05-03 17:40:23 UTC
Jon
Never thought of that!
I assumed that the reader head did the conversion as they have two
sensors and light sources which change over when switched between
metric and imperial. The o/p from these is a sine wave processed by
gates etc so that an up down signal is sent to the display board.
This looked like it had a counter missing (74192) so I have fitted
one to see what happens. It will now read on all the digits but only
counts downwards when on imperial! More checking has revealed that
both up and down streams of pulses are present on the display input
when on imperial. These are sent from the input boards which is full
of gates etc and that is as far as I have got!
I contacted Gurley and they were helpful but the only copy of the
schematic was sent out by mistake to a repairer some years ago and
they do not have anything else or any idea where it went. Sad as the
sensors are shaping up ok.
Peter
Never thought of that!
I assumed that the reader head did the conversion as they have two
sensors and light sources which change over when switched between
metric and imperial. The o/p from these is a sine wave processed by
gates etc so that an up down signal is sent to the display board.
This looked like it had a counter missing (74192) so I have fitted
one to see what happens. It will now read on all the digits but only
counts downwards when on imperial! More checking has revealed that
both up and down streams of pulses are present on the display input
when on imperial. These are sent from the input boards which is full
of gates etc and that is as far as I have got!
I contacted Gurley and they were helpful but the only copy of the
schematic was sent out by mistake to a repairer some years ago and
they do not have anything else or any idea where it went. Sad as the
sensors are shaping up ok.
Peter