Racal Instruments 9901 Maintenance Manual page 53

from
IC5b/10
will
regulafe fhe currenf
in
Q32
to correct
the
error.
On/Off
Switching
4.51
The
single
pole
Power
on/off switch S51 operates
in
the
negative supply from the
rectifiers
D11-D14.
It
also
switches
off
the
+5V
supply by disconnecting the
reference
zener diode
DIO
in
the 'off position.
CPI
Chip
2V
Supply
4.52
A
stabilized
+2V
supply
is
derived from the
+5V
rail
via the regulator
Q14
which
is
controlled
by
Q15
from a reference voltage provided by the
CDI
chip at
IC2/1
1
.
4-10
9901
Vol.2