TeachLogic Forum 232 User Manual
Page 5
a brief word about infrared
Infrared is a light ray that is below the visible
spectrum, just like the sound spectrum extends
beyond your hearing ability. An example of infrared
transmission is the remote control for your TV set.
When a button is pressed, a beam of infrared light
is emitted by a Light Emitting Diode (LED) from the
remote control. It is detected by a receiving diode
in your TV set. When you press a certain command
on your control, the internal electronics cause the
infrared light to flicker in a programmed sequential
pattern (called modulating the light beam). The
modulated infrared beam is detected by the
receiving diode and is electronically decoded. The
decoded signal activates the circuitry to perform
the command function on your TV set.
So how does this apply to the infrared communication
system you are about to start using? The
microphone/transmitter has several Light Emitting
Diodes (LED) that emit infrared light beams to the
sensor located in the corner of the room. Now
when you talk into the microphone, the microphone
element modulates the light beam, causing it to
flicker in sync with your speech. The sensor detects
the sequential signal and the electronic circuitry in
the Forum 232 converts that sequential signal into a
line level analog audio signal. Now that audio signal
can be fed into an amplifier. The amplifier magnifies
the electronic signal and sends it to the speakers.
This causes the speaker cone to move in sync with
your voice. The speaker replicates your voice and
disperses your voice evenly throughout the room.
1
IR transmission
The IR transmitter
transmits directly to the
sensor. However; due to
the strength of the IR
transmitter, the infrared
signal will bounce off the
walls, ceiling and floor for
reception thus providing
continuous connectivity
throughout the room.
Benefit: total freedom
of movement within the
room with no restriction
of orientation.
Infrared will not
penetrate a solid surface
thus preventing any
transmission from
going out of the room.
“What’s said in
the room, stays in
the room”.