8. CIRCUIT OPERATION (HANDSET)
8.1. MAIN BOARD
8.1.1. POWER SUPPLY CIRCUIT
The power supply circuit consists of 4 regulators. IC314 supplies the power to the CPU(IC307).
IC301, IC305 and IC308 are controlled by the CPU(IC307). Each output voltage is 3.0V.
8.1.2. RINGER CIRCUIT
When the Ring signal is received with the power switch of the handset ON, the ringer is
activated. When the ring signal is received, IC307(45) and IC307(46) are, set High or Low.
(Depends on Ringer Vol setting) After Q302 and Q305 are set High or Low, Q304 and Q300 are
switched on by the ringer frequency in IC307(45) (Q300 is a High Current Driver) and the buzzer
is then ON.
8.1.3. RECEIVED VOICE SIGNAL
Содержание KX-TD7895 - Digital Spread Spedtrum Telephone
Страница 3: ...3 2 CONNECTIONS OF HANDSET ...
Страница 4: ...3 3 BASE UNIT ...
Страница 5: ...4 DISASSEMBLY INSTRUCTIONS 4 1 BASE UNIT ...
Страница 6: ...1 Remove the four screws A and remove the Bottom Cabinet ...
Страница 9: ...2 Take the Battery out of the Rear Cabinet after disconnecting the Connector ...
Страница 10: ...3 Remove two Screws D from the Rear Cabinet ...
Страница 12: ...6 Remove the Antenna from the Front Cabinet after removing the Screw E ...
Страница 13: ...7 Remove the RF unit from the Main Board ...
Страница 20: ...34 CHARGE I ON OFF ...
Страница 23: ...6 4 RF UNIT FREQUENCY TABLE ...
Страница 32: ...10 TROUBLESHOOTING GUIDE 10 1 NO VOICE RECEPTION 10 2 NO VOICE TRANSMISSION ...
Страница 33: ...10 3 NO LINK BASE UNIT ...
Страница 39: ...12 CABINET AND ELECTRICAL PARTS LOCATION 12 1 BASE UNIT ...
Страница 40: ...12 2 HANDSET ...
Страница 41: ...12 3 CHARGER ...
Страница 42: ...13 ACCESSORIES AND PACKING MATERIALS ...
Страница 46: ... CAPACITORS ...
Страница 63: ......
Страница 64: ......