Fostex A-8 - Motor and Solenoid Drive Circuits

4.3 REMOTE PUNCH IN/OUT [REMOTE PUNCH IN/OUT]
A latching type foot switch is plugged into the REMOTE PUNCH IN/OUT phone jack
on the rear panel. '
Each time the foot switch is depressed, C15 is repeatedly charged and dis 
charged, producing waveforms shown below.
These signals are shaped by UI and then input to the exclusive OR gate U2-10.
When input pins #8 and #9 are in combinations of "L" and "H" levels, an "H" level
is obtained from its output pin #10 whose waveform is shown below.
Fig. 4-2
U6 is a delayed flip flop which outputs signals shown below upon receiving a
play mode "H" level from U3-10 and the signal from the foot switch.
U8 is a reset circuit, and when the play mode is cancelled, an "H" level is
applied to pin R of U6 and the flip flop is reset. Also, when the GROUP select
switch is manipulated, an "L" reset pulse is applied to U3-13 and the resulting
"H" level from U8-11 applied to the R pin resets U6.
Fig. 4-3
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