Panasonic KX-TCD410SLS Service Manual page 56

EEPROM, LCD)
- RF Module: IC3
- PLL Oscillator
- Detector
- Compress/Expander
- Amplifier for transmission and reception
22.2. Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6V: TP3)
The Reset signal generates R19, C23 and 2.65V.
22.3. Charge Circuit
Circuit Operation:
When charging the handset on the Base Unit, the charge current is as follows;
DC+(5.5V ~ 6V) D4
BATTERY+ ... Battery ... BATTERY-
(Base) GND DC-(GND)
In this way, the BBIC on Handset detects the fact that the battery is charged.
The charge current is controlled by switching Q2 of Handset.
Refer to Fig.101 in Power Supply Circuit
22.4. Battery Low/Power Down Detector
Circuit Operation:
"Battery Low" and "Power Down" are detected by BBIC which check the voltage from battery.
The detected voltage is as follows;
- Battery Low
Battery voltage: V(Batt) < 2.3V
The BBIC detects this level and "
"battery alarm" starts ringing.
- Power Down
Battery voltage: V(Batt) < 2.2V
The BBIC detects this level and power down.
23. SIGNAL ROUTE
TP14(4V) IC3(6, 27), D3
R43, R44 CHARGE+(Base)
R21
().
IC1(37)
CHARGE+(Handset)
GND L5 CHARGE-(Handset)
" starts flashing and
56
IC1(39, 63) (2.65V)
L4 Q2
CHARGE-
F1