Page 10
INDUCTION LOOP
Operation
The audio signal transmitted by the devices connected with the loop amplifier
generate a current inside the loop wire .
The magnetic field generated by the current is picked up by the hearing aid of
the impaired passenger and this allows them to hear the audio signal
properly.
Connecting the audio signal
Connect the audio signal (+) coming from the device to be amplified to
connector
IN+
of the amplifier unit.
Connect the audio signal (-) coming from the device to be amplified to
connector
IN-
of the amplifier unit.
Make sure the jumper for the built-in microphone activation is not inserted (
D
in the picture at page 9).
Connection example with Esse-ti active or 2W speaker unit:
terminal
A
of the speaker unit-> terminal
IN+
of the amplifier unit
terminal
–
of the speaker unit -> terminal
IN-
of the amplifier unit.
Connection example with any Esse-ti autodialer with built-in speech module
(Helpy 2W, Helpy Quick, Helpy Quick-TL, Helpy Vox, ST61):
terminal
ALT2
of the Esse-ti autodialer -> terminal
IN+
of the amplifier unit
terminal
–
of the Esse-ti autodialer -> terminal
IN-
of the amplifier unit.
Connecting the loop wire
Connect one terminal of the loop wire to the
L1
terminal of the amplifier unit
(no polarity to be respected).
Connect the spare terminal of the loop wire to the
L2
terminal of the amplifier
unit.
Placing the loop wire
For a correct audio signal transmission, it is strictly required to place the wire
loop in the most proper position.
Warning: the loop wire must not be tampered with (prolonged,
shortened, altered, …) so as to cause damage.