Components Description - Kenwood kac-9104d Service Manual

● AUDIO UNIT (X09-8750-10)
Ref. No. Application / Function
IC1 Isolation amplifi er
IC2 Phase
IC3 INFRA SONIC FILTER
IC4 LOW PASS FILTER
IC5 BASS BOOST
IC6 (1/2) Triangular wave generation
IC6 (2/2) Error amplifi er
IC7 Comparator
IC8,9 NAND
IC10,11,14 Resonance detection circuit
IC13 Comparator, Control circuit
IC15 DC/DC converter IC
IC16 (1/2) Attenuation circuit to attenuate input signal by 6dB
IC16 (2/2) Attenuation circuit to attenuate input signal by 1.5dB Attenuates output when temperature in the set becomes high
IC17 (1/2) Power supply voltage PWM control
IC17 (2/2) Temperature protection
Q1-3 PCON switch
Q4,5 AUTO Pcon
Q6,7 Mute
Q8,9 DC/DC converter ON/OFF control
Q10 4.4V AVR
Q11,12 DC/DC converter pulse ON/OFF control
Q13-16 Gate driver
Q17-22 DC/DC converter
Q23 FAN drive
Q24-27 AVR
Q28,29 Tracking when ±15V AVR is turned OFF
Q30 HB 15V AVR
Q101,113 D-class amplifi er switch
Q102-112 Pulse amplifi cation, shaping and level shift
Q301-304 Current-voltage conversion
Q305,306 Resonance detection circuit
Q307-311 Latch circuit
Q312 Comparator, Control circuit
Q313 Attenuation circuit to attenuate input signal by 1.5dB Attenuates output when temperature in the set becomes high
Q314 Attenuation circuit to attenuate input signal by 6dB Attenuates output when temperature in the set becomes too high
Q315 Mute
Q701-704 Electric power amplifi cation

COMPONENTS DESCRIPTION

Isolates noises caused by potential differences in GND
Change phase (0° → 180°)
Cuts off ultra low frequency of audio signal
Cuts off high frequency of audio signal
Bass boost (Variable level)
Generates reference signal for digitalizing analog signal
Compensates errors by feedback from the output
Digitalizes by comparing analog signal with triangular waves
Generates and shapes the inverted waveform and to create dead time in D-
class section
Detects short in SP output circuit, measures over current in the circuit, and
activates the protection operation
Controls D/D CON and D-class On/Off with the over current detection and
Pcon control signals
Generates drive signal for switching component
Attenuates output when temperature in the set becomes too high
Controls the dead time of DC/DC converter when the power supply voltage in
the secondary side becomes too high. Prevents the power supply from pumping
Turns off DC/DC converter when temperature in the set becomes too high
Turns on the circuit when ON signal is applied to the PCON circuit
Sends DC voltage from SP IN to Pcon control circuit
Generates mute drive signal and turns off LED
Turns off DC/DC converter when protection is detected
Vef 5V reference AVR
ON or OFF of DC/DC converter drive waveform
Gate driver in DC/DC converter FET
DC/DC converter switching
Limits FAN power supply voltage under the rated voltage
±15V AVR
Matches the trailing edge of "-15V" AVR with that of "+15V" AVR
Stacking AVR to obtain High+B for D-class
Turns the D-class amplifi er ON or OFF
Generates the signal that drives the D-class fi nal FET
Converts current to voltage to detect over current and sends it to the comparator
Detects short in SP output circuit, measures over current in the circuit, and
activates protection operation
Detects abnormal output DC voltage and retains it
Controls D/D CON and D-class On/Off with the over current detection and
Pcon control signals
Turns off audio signal
Switching of D-class high current
KAC-9104D
Operation / Condition / Compatibility
3