Technical/Programming Manual
FT1020G3 Rev 2.2.1
45
Table 8 Connection of the Audio Amplifier 60W, 120W and 250W
Designator
Type
No.
Label
Pin
Description
CON1
Screw
terminal
1
24Vdc
+
Power input. 19V - 32V, 2.8A (60W), 5.2A
(120W), 10A (250W)
2
-
CON2
Screw
terminal
1
AUDIO IN
+
Audio input <=1 V
RMS
. Input impedance:
10K.
2
-
3
STDBY
Audio amplifier enable/disable input, logic
5V, <= 5mA. It is to minimize the unit power
consumption.
The amplifier output will be disabled when
the input is high.
CON3
Screw
terminal
1
AUDIO
OUTPUT
+
Audio output to the transformer secondary
side on the main control board. 16V
RMS
to
the associated different transformer.
2
-
6.4.3
OWS Volume Adjustment
All volume adjustments are made on the Audio Amplifier Module via the trimpot VR1 only.
This volume adjustment is given a reference designator, VR1 and named “VOLUME” on all
amplifier boards. This trimpot, VR1, is shown in both Figure 18 page 43 and Figure 20 page
44.
Do not use VR2 for adjusting the volume at any time, VR2 is only used for factory
calibration purposes.
The following procedures describe how to adjust the volume.
1. Manually turn on the evacuation tone.
2. Adjust the trimpot clockwise a little at a time to increase the volume on the audio
amplifier.
3. Then test or measure if the required audio level is met. Specious
4. Repeat 1 to 3 as necessary.
6.4.4
Auxiliary Audio inputs
The OWS provides an auxiliary audio input controlled by a supervised auxiliary enable
input. The auxiliary audio input can be connected to a background music source and
enabled via the auxiliary input. The auxiliary inputs are also used to connect the Brooks
remote desktop microphones. When the CIE is in quiescent conditions and the auxiliary
enable input is activated, the auxiliary audio is activated and remote PA announcement or
background music will be broadcasted across the speakers.
Note
: Shielded cables must be used for Audio signals and its shielding should be
connected to the CIE EARTH terminal, this is to reduce disturbances.
6.4.5
OWS Dual Strobe Output
The OWS Dual Strobe output circuit is shown in Figure 21. A small current flows through
one of the two strobes constantly, which is normally too small to activate the strobes in
normal conditions. The EOL resistor of the output is 47K, however, the EOL resistance may
vary based on the strobe model connected. Multiple dual strobes can be used.
Figure 21 Typical OWS Dual Strobe Control Circuit