Panasonic KX-TG6500BXB Service Manual page 94

KX-TG6500BXB / KX-TGA650BXB
18.3.1. Charge Circuit
The voltage from the AC is supplied to the charge circuits. Main charge (180mA at the Battery) of maximum 6-hours is started
soon after the Handset is placed on the Base Unit. Then it changes to Trickle charge to prevent from overcharging.
Q361 and Q362 detect the ON-HOOK state (Handset is placed on Base Unit).
Q371 and Q372 control the charge current.
Q373 sends a signal to the Handset for about 5 seconds soon after the Handset is placed on the Base Unit.
This signal tells that the Handset is been charging on the Base Unit or the optional charger.
When the signal is received: charging on the Base Unit
No signal: charging on the optional charger.
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