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connected to
resonance circuit
Q
1
UP
Q } connected to
resonance circuit
Q,
DOWN
Lyvref
Strobe
Data
CLOCK
Control Data Structure
ll
ol
5
4
3
2
1
1
|
0
9
8
7
6
esfesfes[e[-[e]:
[ mae
position
position
Bi
position
ia
6 5
4321
no change
no change | 0 0
—12dB}
0110
Qi
01
—10
0101
Q2
10
—8
0100
Q+Q:
[11
—6
—4
0010
~—2
0001
0
0000
+ 2
ool
+4
1010
+6
1011
+ 8
1100
+10
1101
+12
1110
input =>
SEQ-555ES
AUTOMATIC
ACOUSTIC
COMPENSATION
Pink noise is output from the oscillator inside this
set and radiates from the speaker. These signals are
input
at the
microphone,
divided
into
10 bands,
measured
and analyzed,
then equalization is applied
to flatten frequency response.
The
signal input from the MIC jack is amplified at
the ICy9;
mic amp
circuit. (The frequency response
is corrected at the same time.)
The
amplified
signal is applied to ICs;g. The ICs)
output
signal is applied to the frequency
filter cir-
cuits,
then
is rectified
at the rectification
circuit,
passes the multiplexer circuit and is digitalized at the
A/D
converter,
and is memorized
in the RAM
by
microcomputer B.
The
equalizer is controlled by this memorized
con-
tent to flatten frequency response.
FILTER
CIRCUIT
IC,
rectification circuit
In the circuit above, the RLC
resonance
circuit is
formed
by Q1, C2, C3, R2 and R3. IC,, Cy, Ri and
the resonance circuit form a band pass filter.
C2, C3, Ro and R3 determine the center frequency.
a
1
10 pe J RIRICIC
After passing the filter circuit, it is converted to DC
voltage by the rectification circuit. This DC voltage
is applied to the A/D converter via the multiplexer.
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