汽车音频功放电路图.pdf

POWER AMPLIFIER
KAC-649S
SERVICE MANUAL
© 2001-4 PRINTED IN KOREA
B51-7802-00 (K) 3387
LR
B
INPUT SENSITIVITY(V) INPUT SENSITIVITY(V) INPUT
R
(MAX)
(MAX)
(MIN)5
(MIN)5
A
4
4
SPEAKER LEVEL INPUT LEVEL SPEAKER


3
3
GND
2
2


L
1
1
HPF HPF
LPF LPF
STEREO
MONO (Lch) MONO
STEREO
MONO (Lch) MONO
A B A
OFF OFF
+
B A B A
OPERATION
OPERATION
INPUT SELECTOR INPUT
FILTER FILTER
LINE IN LINE OUT LINE IN LINE
POWER IN BRIDGED
SPEAKER
LEFT RIGHT
FUSE(25A) BATT. OUTPUT
A
25
B
POWER AMPLIFIER
KAC-649S
COMPONENT DESCRIPTION
AUDIO UNIT (X09-5420-10)
REF. No. FUNCTION OPERATION
Q1-4 MUTE Decreases shock noise in first moment when . turns on or off.
Q5-12 DIFFERENTIAL AMPLIFIER
Q13 RIPPLE FILTER
Q14-17 DIFFERENTIAL AMPLIFIER
Q18-21 PENSATION Detects temperature of the heat sink, and protects bias current drift.
Q22-29 OVER-CURRENT PROTECTION Detects over-current, and limits the power stage current.
Q30-37 POWER AMPLIFIER DRIVER
Q38-45 POWER STAGE
Q46 . DETECTION Detects -ON, and turns Q47 on or off.
Q47 POWER SWITCH Supplies power to IC5.
Q48 MUTE ON/OFF Turns Q49 on or off.
Q49 MUTE DRIVER
Q50,51 SWITCHING POWER STAGE
Q52 OVER-CURRENT PROTECTION The detected over-current stops IC5's working.
Q53 OVER-VOLTAGE PROTECTION When over-voltage puts on BATT, Q53 turns . off.
Q54,55 CONSTANT VOLTAGE POWER SUPPLY Supplies + and - 15V power.
Q56,57 SWITCHING DRIVER
Q58-61 DIFFERENTIAL AMPLIFIER
Makes an input signal 6 more dB signal,
IC1,2 INPUT BUFFER / ISOLATION AMPLIFIER
and cancels automobile noise.
IC3,4 (1/2) : LPF
IC3,4
IC3,4 (2/2) : INVERTER
IC5 SWITCHING REGULATOR Oscillator for DC/DC converter.
2
KAC-649S
ADJUSTMENT
INPUT OUTPUT RECEIVER ALIGNMENT ALIGN
No. ITEM FIG.
SETTINGS SETTINGS SETTINGS POINTS FOR
Connect a cassette