Panasonic KX-TG7100ES Service Manual

Contents

9KX-TG7100ES/KX-TG7102ES/KX-TG7103ES/KX-TGA710ES4.2.2. Power Supply CircuitThe power is supplied to the DECT BBIC, RF Module, EEPROM and Charge Contact from AC Adaptor (+6.5 V) as shown inFig.101. The power supply is as follows;• DECT BBIC (IC7):CN2 (+6.5 V) → IC1 → Q9 → IC7CN2 (+6.5 V) → IC1 → Q8 → IC7• RF Module (IC10):CN2 (+6.5 V) → IC1 → Q9 → IC10 (PLL)CN2 (+6.5 V) → IC1 → Q10 → IC10 (Power AMP)• EEPROM (IC5):CN2 (+6.5 V) → IC1 → Q9 → IC5• Charge Contact (TP16):CN2 (+6.5 V) → R55, R56 → TP164.2.3. Telephone Line Interface• Bell signal detection• Clip signal detection• ON/OFF hook circuitBell & Clip (: Calling Line Identification Presentation: Caller ID) signal detection:In the standby mode, Q3 is open to cut the DC loop current and decrease the ring load.When ring voltage appears at the L1T (A) and L1R (B) leads (when the telephone rings), the AC ring voltage is transferred asfollows;• A → C4 → R6 → R33 → IC7 Pin 60 (CID INp)• B → C3 → R4 → R35 → IC7 Pin 52 (CID INn)ON/OFF hook circuit:In the standby mode, Q3 is open, and connected as to cut the DC loop current and to cut the voice signal. The unit is conse-quently in an on-hook condition.When IC7 detects a ring signal or press the TALK Key onto the handset, Q4 turns on and then Q3 turns on, thus providing anoff-hook condition (DC current flows through the circuit) and the following signal flow makes the loop current.• A → D3 → Q3 → Q5 → R21 → R22 → D3 → B [OFF HOOK]