Circuit Description; Coaxial Relays; Line Relays; Alarm And Fault Triggers - RF Technology Eclipse Series Operation, Maintenance And Installation Manual

3 CIRCUIT DESCRIPTION ______________________________________________

Function/Signal
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3 Circuit Description
The following descriptions should be read as an aid to understanding the schematic
diagram at the rear of this manual.
3.1

Coaxial Relays

The coaxial relays switch the RF signal path between two repeaters. A separate relay
is used for antenna – receivers and another for antenna – transmitters. Both relays are
powered ON in normal operation, in the MAIN mode. Transistors Q10 and Q11 drive
each relay. In STANDBY mode the relays default to OFF position so are particularly
suitable for monitoring an ac or dc power failure condition.
3.2

Line Relays

The relays RL1, RL2, RL3 and RL4 provide the input/ output signal line switching
facility. Transistor Q9 drives these relays in unison with Q10 and Q11 operation.
All relays operate together. Either all are ON or all are OFF.
The schematic shows the relays in STANDBY or OFF position.
Four signal lines are switched through RL1, RL2 and the DB-25 connector. Another
three signal lines are available for user expansion switched through RL3 and the DB-9
connector.
3.3

Alarm and Fault Triggers

ATI Alarm output
The HSS is designed to work with the Eclipse Alarm Trunking Interface (ATI) and
can also be easily interfaced to third party equipment. The ATI combines the receiver
and transmitter alarm signals and the output is brought to a common pin (ATI card
DB-25 Pin 4). The ATI also monitors and will alarm if either the receiver or
transmitter is disconnected from the rack frame connector.
In alarm condition the standard ATI output is Alarm_High.
RF Technology Hot Standby Switch
Option DB-9 Pin Connector
Pins
5
9
4
8
3
7
2
6
1
Relay Standby Position
Closed
Link
Open
Closed
Link
Open
Closed
Link
Open
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