User's Manual

VHF Headstation & In-Line Amplifiers
User Handbook
Handbook Nō.-50-127201FCC Issue No:-A
Date:-14/06/2005
Page:-
34 of 45
4.10 24V Single Relay Board (80-008902)
4.10.1 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.
4.11 24V, 400W Power Supply Pack (96-300054)
4.11.1 Description
The power supply unit is a switched-mode type capable of supplying 24V DC at 17.0Amps
continuously. Equipment of this type typically requires approximately 10.0 Amps at 24V
DC, so the PSU will be used conservatively ensuring a long operational lifetime.
No routine maintenance of the PSU is required. If a fault is suspected, then the output voltage
from the power supply may be measured on its output terminals. This is typically set to
24.5V using the multi-turn potentiometer mounted close to the DC output studs on the PSU
PCB.
All the PSU’s used in AFL Cell Enhancers are capable of operation from either 110 or 220V
nominal AC supplies. The line voltage is sensed automatically, so no adjustment or link
setting is needed by the operator.
4.11.2 Technical Specification
AC Input Supply
110 or 220V nominal
Voltages:
90 to 132 or 180 to 264V (absolute limits)
Frequency: 47 to 63Hz
DC Output Supply:
24V DC (nominal)
Voltage:
20 to 28V (absolute limits)
Maximum current: 17A