HME 46-3, HMD 46-3
02/2008
5.2.6 Testing of the ActiveGard
™
of the PCB (not HMD/E 46-31)
1. Connect the sine wave generator with the negative and the positive line at TP3 (+) and TP4 (-), see “Printed
2. Measure the output signal at TP8 (+) and TP9 (-), see “Printed circuit boards”, page 19.
3. The following table show you the input levels of the signal generator and the corresponding
measurement results:
Figure 1
Operational test of the dynamic microphone
Input signal of 1 kHz
at TP3 (+) and TP4 (-)
of the PCB
Output level at TP8 (+) and TP9 (-):
Audible via loudspeaker
Output level at TP8 (+) and TP9 (-):
Damaged loudspeaker or open
cable connection
300 mV
eff
±
5 mV
Output level is reduced about
min. 8 dBV. The PCB with
loudspeaker works correctly.
290 to 310 mV
eff
1 V
eff
±
5 mV
30 to 40 mV
eff
Speaker´s voice
Audio amplifier
output
Headphone
connector
input
Microphone
connector
output
Oscilloscope
