Toa IR-200M, Service Manual

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IR-200M Y
11 11
Low frequency section
RF and IR section
PLL synthesizer section
Power supply section
Electret condenser
microphone
Bias circuit
R300, 302
Microphone amplifier
M302(1/2)
Pre-emphasis
M302(1/2)
Low-pass filter
Q300
Buffer amplifier
Q4
RF amplifier
M200
LED driver
M201
Q202, 203
Infrared emitting LED
LED200-202
Infrared emitting LED
LED203, 204, 1
Power selector switch
SW101
Green Red
IR bias control
Battery voltage monitor Reset
Battery checker
LED100
LED driver
M202
Q205, 206
Ripple filter
Q5
Loop filter
IR bias control
Q200, 201
Drive current control
Q204, 207
AF level control
VR300
RF level control
VR1
VCO
Q2, 3, 5
D1, 5
Voltage detector
M101
Compressor
M300
DC-DC converter
M102, Q101, D104
Tone oscillator
M303, 304, X300
Channel selector switch
SW100
CPU (control)
M100
Clock
X100
6.000MHz
DC 5.0V
DC 5.0V
AF mute
M3
DC 2.4V
OFF detection
Q100
M
Circuit switch
Q102, 103, 105
Circuit voltage
DC 5.0V
Power switch
SW102
Circuit voltage
DC 2.4V
Battery
terminal
Charging
terminal
PLL
M4
Amplifies signals
from microphone
element.
Amplifies high frequency
components of audio
signals at time constant
of 300 μs.
Serves as a buffer
and cuts 15 kHz or
higher frequencies.
Logarithmic-
compresses audio
signals to 2:1.
Supplies power to
microphone
element. Oscillation circuit
uses C-MOS
inverter.
Performs system control,
frequency data transmission to
PLL, and battery voltage monitor.
Serves as an
impedance converter
as well as a buffer.
Oscillates transmitting
frequency in
conjunction with PLL.
Amplifies
RF signals
from VCO.
Frequency-divides and phase-compares each
output from reference oscillator (6 MHz) and
VCO, generating pulses depending on the phase
difference.Comparison frequency is 25 kHz.
Low-pass filter to produce
control voltage (DC) for
VCO by using pulses
generated from PLL IC.
Controls power
supply to Infrared
emitting LED.
Converts voltage of RF signals into
current, and amplitude-modulates
infrared lights generated from
infrared emitting LED.
Switches LED drive
current to output infrared
lights in High or Normal
mode.
Creates 5 V DC
from battery
voltage.
Turns on and supplies 5 V DC to the entire circuit to operate when the power
switch is turned on. Once the CPU starts operating, it controls the circuit switch.
The circuit switch turns off through OFF control and termination operations
when the power switch is turned off. It also turns off when the battery voltage
drops to 2 V or less, disconnecting the following circuits and preventing
over-discharge of battery.
• IR-200M
BLOCK DIAGRAMS AND OPERATION DESCRIPTION
BLOCK DIAGRAMS AND OPERATION DESCRIPTION