Power Circuit And Redial Back-Up Circuit - Panasonic KX-TS550MEB Service Manual

12.3. Power Circuit and Redial Back-up Circuit

Function:
This set is powered from the line. When it is an OFF-HOOK status, Tel Line → D17 → Q1 → R9 → Pin 27 of IC1 (to become
the power supply for IC1 speech network).
The voltage from the line is turned into a constant voltage by D2 and then supplied to the IC1, reset circuit.
Through Tel Line → R1 → R3 → D17 → R14 to become the power supply for IC1, and the redial Back-up will be done.
17
KX-TS550MEB / KX-TS550MEW