6
a brief word about infrared
Infrared is a light ray that is below the visible spectrum, just like sound 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.
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 amplifier 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.
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”.
