Service Manual

GSM-204-323
Control and alarm board (CAB)
31st Oct 01
Technical Description: Horizon macro outdoor
68P02902W02-A
CONTROLLED INTRODUCTION
Tech. 4–23
Battery selector
The battery selector switch connects two 4 mm DM sockets on the CAB front
panel to the internal batteries, to allow measurement of:
 Total battery voltage.
 Individual battery voltage.
 Battery current, measured by millivolt equivalent (0.75 mV equals 1 A).
Figure 4-16 shows the battery selector test circuit.
5K1
5K1
5K1
5K1
5K1
5K1
1
+I
–I
C28
B28
f
a
a
b
c
d
e
b
c
d
e
DM
SOCKETS
BLUE
BLACK
0 V
–12 V
–24 V
–36 V
–48 V
f
CONTROL BOARD
2
A32
B31
A31
A23,24,25
B32
Figure 4-16 Diagram of the battery selector test circuit
Table 4-2 shows the expected DMM values for each position of the test switch.
Table 4-2 Battery selector switch test values
Test switch setting Reading Cell under test
a – 48 V dc All
b –12 V dc Cell 1
c –12 V dc Cell 2
d –12 V dc Cell 3
e –12 V dc Cell 4
f Battery charge
current
All