Aastra Ascotel IntelliGate 2065 - 7.5.5.4 Connecting a loudspeaker system

Ascotel IntelliGate 2025/2045/2065
812 Cabling interfaces Part 4
• If the door intercom interface is DC-free and has a high input impedance (≥
600 Ω), connect the output path (in the loudspeaker direction) to Ta and signal
ground SGND.
• If the door intercom interface is not DC-free and if it has a low input impedance
(< 600 Ω), connect the output path (in the loudspeaker direction) to LS and sig-
nal ground SGND. In this case power the interface at the AC and AC’ connec-
tions via an external bell-ringing transformer with 8...12 VAC and set the vol-
ume control to minimum.
7.5.5.4 Connecting a loudspeaker system
The loudspeaker system is connected via a line input (e.g. audio input for adver-
tising texts) or a microphone input. The input should have a priority circuit and a
separate volume control. The priority circuit is used to fade out the background
music when an announcement is being made.
[1] Jumper (1-2) for asymmetric input
R
1
, R
2
, R
3
voltage divider when using a microphone input
Fig. 4.78: Schematic circuit diagram of the connection variant for a loudspeaker system
• When using a microphone input on the loudspeaker system:
– Since microphone inputs are usually designed for low signal levels only, use
a voltage divider to reduce the signal from the door intercom interface (R
1
,
R
2
, R
3
).
– Use a screened cable for the microphone wires for the connection between
the PBX and the loudspeaker system.
– Connect the cable screening to the loudspeaker system only, not to the PBX
or else ground loop humming will occur.
• Connect the loudspeaker system input to Ta and Tb.
• Connect the priority circuit to TS and TS’.
R
1
330
Ta
Tb
TS
TS'
R
2
330
R
3
10
[1]
Loudspeaker system
Microphone input (Pin 3)
1
4
2
5
3
haz1156aaenb0