KX-NCP1174XJ (serv.man2) - Panasonic PBX Service Manual (repair manual). Page 17

Read Panasonic KX-NCP1174XJ (serv.man2) Service Manual online

17
     KX-NCP1174XJ
5.2.13. Power Supply Voltage Generator
The input from the main power supply is in 3 voltage levels: +15V, +30V, +40V.
Since the voltage levels: +15V, +5V, +3.3V, +40V, +160V, -100V and AC 75Vrms are required onboard, voltage levels are generated
onboard as written below.
The protection circuit consists of an output short protection and an overvoltage protection.
When an output of power supply is short, IC7 or IC10 works to stop the output as the output short protection.
When +5V and/or +3V output become overvoltage caused by Q12 and/or Q13 short, it is detected by D20 and D21. Q15 is cut by
Q16 to shut down the input power supply as the overvoltage protection.
Page of 67
Display

Click on the first or last page to see other KX-NCP1174XJ (serv.man2) service manuals if exist.