Main Converter - Panasonic KX-NS500AG Service Manual

2) Rectification Smoothing Circuit
This circuit consists mainly of the following components and performs DC-AC conversion.
D1: Diode Bridge
C5: Primary Smoothing Condenser
3) Surge Absorber Circuit
As the main component of this circuit, Z1 protects against exogenous noise such as lightning surge.
Z1: Varistor
4) Inrush Current Avoiding Circuit
Immediately after AC input applies voltage, the following components control inrush current to the Smoothing Condenser.
NTC1, NTC3: thermistor
5) AC Detection Circuit
This circuit consists of the following components and detects AC input.
Main components: D81,D82,R80-R95,Q80,Q81,Q82,PC80
AC voltage commutates through D81, D82.
When AC voltage is over the threshold, Q80, Q81, and Q82 are switched ON to allow AC Detection Circuit to transfer AC input
status to the secondary side AC alarm signal delivery section through PC80
4.7.

Main Converter

This section describes the main converter circuit which insulates the primary DC voltage and converts the voltage to a Secondary
voltage (41V output).
1) Main Converter Section (Primary)
This main converter consists of the following components; Isolated, and Self-excited Pseudo Resonance Type Converter.
Q1: main switch FET
T101: isolation transformer
IC1: IC controls Q1
PC1: device for transfer control secondary side
Other peripheral circuit
Secondary side output condition is transferred by PC1 to the primary side.
Q1 is switched to ON/OFF in IC1 to control the secondary side voltage.
2) Main converter section (Secondary)
T101: The output of this isolation transformer is 41V, and is the power supply for output voltage in section 3.
41V output:
This output consists of the Rectification Smoothing Circuit of D101, C101.
This is the output described in section 3, 15V and 41V output for power supply, and also for battery output as described in
section 4.
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KX-NS500AG