KX-NSX1000, KX-NSX2000 - Panasonic PBX Service Manual (repair manual). Page 12

12

Provides a description of the main converter that insulates primary DC voltage and converts it to secondary (32V output). 

1. Main converter section (primary side)

Consisting of the following parts, the primary side main converter is an insulated, separately-excited flyback converter. 
Q1: Main switch FET
T1: Insulated transformer
IC1: Control IC for Q1 control
PC1: Secondary control transmission element
Other peripheral circuitry
Secondary output status is transmitted from PC1 to the primary side; on/off control is executed by IC1 to control secondary
voltage. 

2. Main converter section (secondary side)

This is a T1 isolation transformer output, consisting of rectification smoothing circuits of D101, C102, C106 to C11. 
32V output and power source for output voltage (Refer to Part3).

3. Latch Operation Section

Latch circuit for main converter stop due to abnormal state such as excessive output voltage.
Transmits abnormal state detected on secondary side (described in Part 5) to IC1 by PC2 primarily using the IC1 latch func-
tion and stops the main converter by latching. 
Latching is canceled 60 seconds after the source of the abnormal state is removed and AC input is off, and is reset to ordinary
operation when AC power is turned back on.