22
en | Maintenance
Airman 850
09-2021 | V07 | F.01U.264.819
Customer maintenance manual
Bosch Security Systems LLC
RED
GREEN
COPPER
Figure 6.3:
Airman 850 headset, boom assembly reference view
Red Wire
Green Wire
Copper Wire
Vcc = 3.3V
V out
Ground
DEVICE UNDER TEST
3.
Follow the steps 4 through 8 in
Microphone / amplifier sensitivity check, page 20, and
then measure the output of the boom microphone. The output should be 24 mVRMS ± 7
mV
i
Notice!
If the output does not fall within the tolerances, adjust the gain pot as shown in the previous
illustration.
This test is not designed for absolute accuracy, but rather to tell if the boom assembly is
functioning properly.
If no output or no acceptable output is obtainable, then replace the boom assembly.
Testing the Circuit board assembly
To test the circuit board assembly, do the following:
1.
Construct a test circuit. For more information, see illustration below.
2.
Connect the circuit board to the test circuit.
With
Vin
measuring 100 mVRMS 1 Khz,
V out
should read 210 mVRMS ±60 mV.
If the output is outside this range, replace the circuit board.
12 Vdc
25uf
25 Vdc
220
V OUT
J8
J9
J2
J3
25uf
+
V IN
600
470
1/2W
DEVICE UNDER
TEST
Figure 6.4:
Airman 850 headset, circuit board test diagram
Summary of Contents for Airman 850
Page 1: ...Airman 850 AIRMAN 850 Headset en Customer maintenance manual ...
Page 2: ......
Page 33: ......
