User's Manual

Two Channel 400MHz Cell Enhancer
User Handbook
Handbook N.-50-128501HBK Issue No:-A
Date:-12/08/2005
Page:-
29 of 39
4.11 12V Single Relay Board (80-008901)
4.11.1 Description
The General Purpose Relay Board allows the inversion of signals and the isolation of
circuits. It is equipped with a single dual pole change-over relay RL1, with completely
isolated wiring, accessed via a 15 way in-line connector.
The relay is provided with polarity protection diodes and diodes for suppressing the
transients caused by "flywheel effect" which can destroy switching transistors or induce
spikes on neighbouring circuits. It’s common use is to amalgamate all the alarm signals
into one, volts-free relay contact pair for the main alarm system.
Note that the board is available for different voltages (12 or 24V) depending on the type
of relay fitted at RL1.
4.12 PP9 NiCad Backup Battery (96-000017)
The NiCad rechargeable battery fitted in this system is trickle-charged from the main 12V
supply by a diode and resistor and powers the RS232 controller/monitor board and the
telephone line modem in the case of a power failure. This gives the controller and modem
sufficient time to dial out and alert the control centre of the new (failure) status of the