RADIOMETER TCM3 - Page 80

2. TCM3
TCM3 and TCM30 Service Manual
Output PCB
Description
This PCB is found in TCM3 of RUN 22 onwards and in TCM30.
The
PCB
which
is
mounted
on
the
Power
Supply
PCB
as
a
“piggy
back”,
includes
a
switching
FET
and
various
logic
circuitry.
The
PCB
is
powered
only
(Vsroe
and
+5V),
if
the
monitor
is
mains
supplied.
01
15
оп
when
the
gate
is
low
(O2
on).
When
REC
is
connected
to
the
monitor
(TCM3
only),
J6/6
is
low.
When
BAT
is
connected
to
the
monitor,
terminal
J6/7
is
low.
When
the
monitor
is
switched
on,
J6/8
is
low.
If BAT is connected to the monitor, Q6 cuts off, and Qt goes on via QDID and
Q2. QDI/A pin 3 goes high.
If the monitor is switched on, Q7 cuts off and QD1B pin 6 goes low. Q4 cuts off
and QS5 saturates and J6/6 goes low. This makes a FET in BAT, similar to O1,
switch off the charge current to BAT.
If BAT is connected to the monitor, it will be charged only if the monitor is
switched off.
If the monitor is switched on and REC is connected (TCM3 only), then ODUC pin
8 goes low, QD1/D pin 11 goes high, Q2 saturates, Q1 goes on and the recorder is
supplied by Voarmce:
annaan +