Kenwood KAC-M1804 Service Manual page 5

Ref. No.
D201 Diode for -26dB ATT circuit and Auto P-
Con control
D233 Diode for -26dB ATT circuit error prevention Prevents -26dB ATT circuit from turning on when P-CON is Hi
D215 Temperature protection circuit diode
D216
IC7 Temperature protection circuit
OP-AMP
Q203, Q204 Transistor for DC protection and ± 11.5V
power protection
IC8 OP-AMP for primary overcurrent protection
circuit
D228 Diode for primary overcurrent protection
circuit
D208 Zener diode for BATT overvoltage detec-
tion circuit
Q215 Transistor for BATT overvoltage detection
circuit
D232 Zener diode for BATT reduced voltage de-
tection circuit
Q213, Q214 Transistor for BATT power ON/OFF control
D207 Zener diode for prevention of P-CON cir-
cuit error operation
Q211, Q212 Transistor for latched circuit
IC9 DC/DC converter control IC
D206 Diode for prevention of DC/DC IC error op-
eration
D214, D219 Diode for temperature protection control
Q210 Transistor for temperature protection control
Q205 - Q207 FET for DC/DC switching
Q208, Q209 Transistor for gate voltage drawout
D204, D205 Diode for gate voltage drawout
D224 - D227 Diode for ± B power rectification
Q216 Transistor for +11.5V power
Q217 Transistor for -11.5V power
D209, D210 Zener diode for ± 11.5V power
Q219, Q220 Transistor for reducing shock noise
Q226 Transistor for +5V power
Q227 Transistor for -5V power
D212, D213 Zener diode for ± 5V power
Q218 Transistor for -B+12V power
D211 Zener diode for -B+12V power
Q229, Q230, Q231 Transistor for use by auxiliary circuit during
reduction in the -B+12V power supply
D202, D229 Diode for use by auxiliary circuit during re-
duction in the -B+12V power supply
Q221 Transistor for D-AMP IC output ON/OFF
control
Q222
D217 Diode for D-AMP IC output ON/OFF control
Application / Function
(No.WA122<Rev.002>)5/7
Operation / Condition / Compatibility
5.1V Zener diode for the temperature protection circuit
Protection when there is abnormal DC output to SP OUT, or
when the voltage of the ± 11.5V power supply is abnormal
Protection when the primary current is about 17A or higher.
Not latched. Automatic restoration after a few seconds.
Powers off when BATT voltage is 17V or higher.
Powers off when BATT voltage is 7.8V or lower.
Latched circuit for DC protection and power protection
Stops DC/DC converter oscillation and stops ± B supply when
temperature protection is detected.
Shuts down the +11.5V power faster than the -11.5V when
powering off.
Q221 ON → AMP output OFF
Q222 ON → AMP output OFF