Components Description - Kenwood kac-8104d Service Manual

● AUDIO UNIT (X09-8730-10)
Ref. No. Application / Function
IC1 DC/DC converter IC
IC11 Isolation amplifi er
IC12,13 NAND
IC14 INFRA SONIC FILTER
IC15 BASS BOOST
IC18 LOW PASS FILTER
IC31 (1/2) Triangular wave generation
IC31 (2/2) Comparator
IC32 (1/2) Triangular wave generation
IC32 (2/2) Error amplifi er
IC60 Attenuation circuit to attenuate input signal by 1.5dB Attenuates output when temperature in the set becomes too high
IC61,62,64 Resonance detecting circuit
IC63 Comparator
Q1-3 PCON switch
Q4,5 Mute
Q6 DC/DC converter ON/OFF control
Q8-11 Gate driver
Q12,13,19,20 DC/DC converter
Q25,26,28,42 AVR
Q29,30 Tracking when ±15V AVR is turned OFF
Q37,38 DC/DC converter pulse ON/OFF control
Q51,52 AUTO Pcon
Q151 Mute
Q400,403 D-class amplifi er switch
Q401,402
Q404-409,414 Pulse amplifi cation, shaping and level shift
Q415,417
Q410-413 Power amplifi cation
Q416 HB 15V AVR
Q600,601 Resonance detecting circuit
Q602,612 Protection
Q603 Attenuation circuit to attenuate input signal by 1.5dB Attenuates output when temperature in the set becomes too high
Q604-607 Current-voltage conversion
Q608-611 Latch circuit
Q900 FAN drive

COMPONENTS DESCRIPTION

Operation / Condition / Compatibility
Generates drive signal for switching component
Isolates noises caused by potential differences in GND
Generates and shapes the inverted waveform and to create dead time
in D-class section
Cuts off ultra low frequency of audio signal
Bass boost (Variable level)
Cuts off high frequency of audio signal
Generates reference signal for digitalizing analog signal
Digitalizes by comparing analog signal with triangular waves
Generates reference signal for digitalizing analog signal
Compensates errors by feedback from the output
Detects short in SP output circuit, measures over current in the circuit,
and activates protection operation
Controls D/D CON and D-class On/Off with the over current detection
and Pcon control signals
Turns on the circuit when ON signal is applied to the PCON circuit
Generates mute drive signal and turns off LED
Turns off DC/DC converter when protection is detected
Gate driver in DC/DC converter FET
DC/DC converter switching
±15V AVR
Matches the trailing edge of "-15V" AVR with that of "+15V" AVR
ON or OFF of DC/DC converter drive waveform
Sends DC voltage from SP IN to Pcon control circuit
Turns off audio signal
Turns on or off D-class amplifi er
Generates the signal that drives the D-class fi nal FET
High-current switching in D-class
Stacking AVR to obtain High+B for D-class
Detects short in SP output circuit, measures over current in the circuit,
and activates protection operation
Turns off DC/DC converter when protection is detected
Converts current to voltage to detect over current and sends it to the
comparator
Detects over voltage in output and retains the current
Limit FAN power supply voltage under the rated voltage
KAC-8104D
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