Pfc Controller Circuit; Ic1 (On Main Board); Ac Detection Circuit - Panasonic KX-TDA0103XJ Service Manual

KX-TDA0103XJ / KX-TDA0104XJ / KX-TDA0108XJ / KX-TDA0103X / KX-TDA0104X / KX-TDA0108X

3) PFC Controller Circuit

When the voltage is added to the Vcc terminal (Pin 8 of IC1) of PFC controller circuit, oscillation signal output (Pin 7 of IC1) is
led to the PFC switching circuit, and switches the rectified DC voltage.
As for supplying the voltage to Vcc terminal (Pin8 of IC1), it is fed from PFC start-up circuit on start-up and from Vcc voltage
feeding circuit at normal times. The supply voltage to Vcc voltage feeding circuit is fed from T1 (Sub winding).
(*1) Although it is fed from sub winding of T1 at normal times, mainly fed from Vcc voltage feeding circuit of PFC circuit.
PC1 (on Sub board) detects the operating state of PFC circuit operation and transmits the result to DC alarm detection circuit
(Refer to Alarm Signal Sending Circuit (P.28)).
Refer to Fig.1 (E), (H), (I)

IC1 (on Main board)

Pin1 FB: Voltage error amp -input
Pin2 COMP: Voltage error amp output
Pin3 MUL: Multiplexer input
Pin4 IS: Current sense
Pin5 ZCD: Zero cross current detector input
Pin6 GND: GND
Pin7 OUT: Gate pulse output
Pin8 VCC: Input voltage

4) AC Detection Circuit

Provided the input AC voltage rectified by D16 and D17 at Rectifier Circuit 2 is 80Vrms or above, transistors Q7, Q8 and Q9
(on Sub board) turn ON. The current flows through a diode of PC2 (on Sub board) and reaches the AC alarm detection circuit
(Refer to Alarm Signal Sending Circuit (P.28)).
To put it simply PC2 detects the operating state of the AC detection circuit operation and transmits the result to the AC alarm
detection circuit (Refer to Alarm Signal Sending Circuit (P.28)).
Refer to Fig.1 (F), (G)
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