KRC-478R/RV/RY/RYV
3
COMPONENT DESCRIPTION
SYNTHESIZER UNIT (X14-6xxx-xx)
REF.
No.
FUNCTION
OPERATION
IC1
-COM
Controls system.
IC2
ELECTRIC VOLUME
Switches each source, decodes FM stereo signal, controls sound.
IC4
POWER IC
Amplifies power so that the speaker can drive audio signal.
IC5
EQUALIZER AMPLIFIER
Amplifies and equalizes the cassette head output signal (120
sec).
IC6
SUB MOTOR CONTROLLER
Controls sub motor's loading and eject modes.
IC8
RDS DECODER
Decodes RDS signal from tuner MPX signal.
IC9
-COM RESET
Resets
-COM after detecting the back-up voltage comes
less than 3V.
IC10
MUTE DRIVER
Mutes power IC (IC4) and E-volume (IC2) when the back-up is
detected and
-COM mute signal is output.
Q1,2
BACK-UP 5V AVR
Usually output 5V when battery is connected.
Q3
SW 5V
Outputs 5V when
-COM makes Q3's base level "L".
Q4,5
SW 14V
Q4's corrector outputs the back-up 14V when
-COM makes Q5's
base level "H".
Q6,7
8V AVR
Output 8V.
Q8,9
MAIN MOTOR SW
Output 14V when
-COM makes Q9's base level "H".
Q10-13
ILLUMINATION AVR
Q12's corrector outputs 10.3V when
-COM makes Q11's
base level "H".
Q14
P-CON. START-UP
Cancels Q15's protection circuit effected by C9 time constant and
Q14's inner base resister.
Q15
P-CON. PROTECTION CIRCUIT
Stops output signal, and makes Q16's base level "H" when P-CON
output comes GND shorted.
Q16,17
P-CON. SW
Outputs the back-up 14V when Q17's base level comes "H".
Q18
ACC DETECTION
Corrector level comes "L" when ACC comes "ON".
Detection voltage : 8.95V.
Q19
BACK-UP DETECTION
Corrector level comes "L" when the back-up comes "ON".
Detection voltage : 9.0V.
Q20
-COM RESET
Resets
-COM when Q20's base level comes "H".
Q21
DSI
Indicates when Q21's base level comes "H".
Q51
POWER AMPLIFIER SVR CONTROLLER
SVR level comes "L" when
-COM makes Q51's base level "H".
Q52
PREOUT MUTE CONTROLLER
Mutes preout sound when Q52's base level comes "L".
Q53
ELECTRIC VOLUME MUTE
Mutes E-volume (IC2) signal when Q53's base level comes "H".
Q54,55
AFC
Switches AFC time constant.
Q56
MPX BUFFER
For the front-end MPX output buffer (Emitter follower).
Q57-60
PREOUT MUTE CONTROLLER
Mutes preout sound when Q52's base level comes "L".
Q61
FM+B SW
"ON" when Q61's base level comes "H".
Q62
AM+B SW
"ON" when Q62's base level comes "H".
Q63
FM+B SW
"ON" when Q61's base level comes "H".
Q64
AM+B SW
"ON" when Q62's base level comes "H".
Q65
PANEL SW
"ON" when Q65's base level comes "L" (Panel OFF).
Q67
NOISE BUFFER
For E-volume (IC2) output buffer (Emitter follower).
