Components Description - Kenwood kac-X1R Service Manual

AUDIO UNIT (X09-8560-10)
Ref. No. Application / Function
µ-com
IC1
IC3 DC/DC converter driver
IC5 (2/2) Comparator
IC6 (1/2) Comparator
IC6 (2/2) Comparator
IC7 (1/2) Comparator
IC7 (2/2) Comparator
IC10,11 Isolation AMP
IC12 Buffer AMP
IC13 (1/2) Signal amplification
IC13 (2/2) Signal amplification
IC14 (1/2), Comparator,
IC20 (1/2) Signal amplification
IC14 (2/2) Comparator
IC15,16,21 NAND gate
IC17 NAND gate
IC18 Signal amplification
IC19 (1/2) Signal amplification
IC19 (2/2) Signal amplification
IC20 (2/2) Signal amplification
IC22 Filter
IC24 Signal amplification
BassBoost circuit
IC55~57
(Remote control operation)
Q1,2 POWER ON SWITCH
5V constant voltage
Q3~5
power supply
Q6 SW5V control
Q7 Pcon over voltage control

COMPONENTS DESCRIPTION

Overall control.
Generates the gate waveform for switching.
Compares the analog signal with the triangular wave and generates the PWM waveform for
the minus output-side amplifier of the BTL.
Detects ASO. Compares current with voltage to detect short in the output.
Detects the resonance waveform that is caused when the plus and minus terminals are
shorted in the vicinity of the SP terminals, and protects from the short.
Detects over current with the waveform shaped in IC17 and sends the result of the detection
to the µ-com and the TR used to control the D-class amplifier.
When SP+ or SP- terminal output is shorted to the ground, the current in the + power supply
and that in the - power supply are unbalanced. The unbalance in the current is converted into
DC voltage in Q176 and Q177, and when the voltage exceeds the preset value the output is
reversed and the protection function is activated.
Removes the common mode noises in the input signal.
Buffer AMP for RCA output.
Amplifies the output voltage between the SP + and SP - terminals and generates the NF signal.
Amplifies differences between the input and feedback signals. Initial stage of the D-class amplifier.
Triangular wave generation.
Compares the analog signal with the triangular wave and generates the PWM waveform for
the plus output + side amplifier of the BTL.
To gate pulse of the D-class amplifier.
Retains the pulse width and keeps holds a certain width when IC6 and IC7 (2/2) detect its
individual over current.
Amplifies and rectifies the output voltage at the SP + terminal, and generates DC voltage that
is proportional to the output.
Amplifies the potential differences caused by current running in the GND pattern, and sends
it to the µ-com to obtain current.
Amplifies the DC offset at the SP + terminal, and applies to the DC servo.
Generates the inverted waveform of the triangular wave that is generated in IC14 (1/2) and IC20 (1/2).
Filters and rectifies the resonance waveform that is caused when the plus and minus terminals
are shorted in the vicinity of the SP terminals, and sends the resultant DC voltage to IC6 (2/2).
When 1Ω load is detected, lowers the voltages at pins 1 and 7 and decreases the signal
clipping level in order to limit the SP output.
Boosts the signal with the operations from the remote control.
GAIN=0~+18dB, fc=40~100Hz
Turns ON/OFF DC/DC converter power supply in response to the output from pin 8 of the µ-com.
It is used as the constant voltage power supply of 5V for the µ-com and the SW5V.
Turns ON/OFF 5V to the SW5V line in response to the output from pin 20 of the µ-com.
Blocks the ON signal to the Pcon and places the Pcon in the OFF condition when the battery
voltage is too high.
KAC-PS1D/X1R
Operation / Condition / Compatibility
3