DC ALARM CONNECTION AND SOUND SIGNAL SELECTION
A. Two stage alarm by third core
Strobe shown with common 0v, with sounder
Line monitoring by supply reversal
Select alarm stage 1 on SW1
Select alarm stage 2 on SW2
NOTE: That the two stage control always operates as follows:-
The first stage sounds by supplying volts to a unit via control switch ‘x’,
This switch remains on and the second stage signal is controlled by
switching volts to the third terminal via switch ‘y’
.
Earth
Connection
To Next Sounder
4
3
2
T
B
3
1
3
4
T
B
2
2
Sound Selection
Pressure Unit Connector
x
y
T
B
1
to next strobe
1
4
3
2
1
0v
Sounder
& Strobe
Sounder
+24v dc
Earth
Strobe
+24v dc
LK2 removed (link 24v dc)
LK1 (link 0v)
(On other side of PCB)
(On other side of PCB)
Earth
Connection
4
3
2
T
B
3
1
3
4
T
B
2
2
Sound Selection
Pressure Unit Connector
x
T
B
1
1
4
3
2
1
Strobe
0v
Sounder
+24v dc
Earth
LK2 (link 24v dc)
LK1 (link 0v)
(On other side of PCB)
(On other side of PCB)
resistor (E.O.L)
Earth
Connection
4
3
2
T
B
3
1
3
4
T
B
2
2
Sound Selection
Pressure Unit Connector
x
T
B
1
1
4
3
2
1
Earth
LK2 removed
(link +24v dc)
LK1 removed
(link 0v)
(On other side of PCB)
(On other side of PCB)
resistor (E.O.L)
Strobe
0v +24vdc
Sounder
0v +24vdc
resistor (E.O.L)
Line monitoring by supply reversal
Single Stage Alarm, Sounder and Strobe
operate separately
Line monitoring by supply reversal
Single Stage Alarm, Sounder and Strobe
operate together
D7292/12
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