1.3 System technology
1.3.1 IR radiation
Audio and control signals of teacher in TES-5680 are
transmitted as modulated infrared light. Infrared
radiation is part of the electro-magnetic spectrum,
which is composed of visible light, radio waves and
other types of radiation. Its wavelength is longer in
comparison with the wavelength of visible light.
Infrared light cannot pass through opaque walls and
ceilings thus guarantees privacy of the meeting by
avoiding being intercepted or disturbed. In addition,
infrared light has no radio radiation and a license is not
required when operating infrared light systems.
1.3.2 Carriers and channels
TAIDEN TES-5680 series system adopts 1-8 MHz
wave band. This wave band is suitable for the
transmission of wide band audio and corresponding
signals. TES-5680 uses 4 frequency points of BAND
Ⅲ
and BAND
Ⅳ
in IEC 61603(please refer to table 1.1.)
Route
Channel
Frequency
From
microphone to
TES-568xBX
Group 1
1.67 MHz
2.33 MHz
Group 2
2.33 MHz
3.0 MHz
Table 1.1 Channels and corresponding frequencies in
TES-5680 system
1.3.2 Principle of TES-5680 classroom audio
system
TAIDEN TES-5680 classroom audio system dedicated
to recording teacher’s instruction and students’
interaction in class by integrating digital infrared
technology, DSP technology with array microphone.
The system ensures broadcast level audio quality by
picking up teachers’ sound with IR microphone, and
the sound can be separately routed to the classroom
reinforcement system. A 360-degree array microphone
is used to pick up students’ interactive activities; the
sound will be further processed by the “3A” algorithm
(ANC, AEC, AGC) and then mixed with the teacher’s
audio to be fed into a third-party recording system.
(Figure 1.2)
Figure 1.2
Schematic diagram of TES-5680 classroom audio system
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