Honeywell
COMPONENT MAINTENANCE MANUAL
PART NUMBER 964-0452
1I.B.1516A Page 60
Mar 30/01
23-12-01
(9) ON OFF Module, A15
The ON OFF Module, A15, contains 3 relays for switching ON and OFF the transceiver.
The relay contacts are closed when the line ONREL is connected to ground. Transform-
er, T1, provides an auxiliary voltage of +28V (with relays in operation = 22V) for supplying
the exciting coils of the 3 relays via the protective, thermally-controlled resistor, R1, and
the diode rectifier, V1. On operation, this auxiliary voltage is substituted by the +28V unit
internal voltage. Capacitor, C4, ensures, on primary voltage drop, that the relays do not
release during the 10ms transparency time.
Further, the module provides the supply voltage for the internal blower (BLOWHI, BLOW-
LO). For protection against HF interference from the power amplifier, the supply voltage
is connected with the sockets, X40.1 and X40.2 via each lead-in filter and an LC circuit.
Page 90
To Next Page
Loading...
