
7.8. HOOK SWITCH CIRCUIT
1) Circuit Operation
The hook switch of this unit employs the photo switch consisting of LED and photo transistor. The
2kHz pulse from the gate array of IC2 causes the LED to emit the light. The light is interrupted at ON-
HOOK and passes through at OFF-HOOK by the hooking bar,so that the hooking is performed
controlling the light of the photo transistor. The detection signal is determined by the microcomputer
of IC6.
7.9. HANDSET CIRCUIT
1) Transmission signal path
The analog input signal from the handset microphone is input to the communication LSI through the
IC2 built-in analog amplifier. In this LSI the network control based on A/D conversion and the handset
software and the gain control based on the down load data from the PBX are performed. The voice
data is sent to IC1 by the serial transmission. The voice data is transmitted between PBX and DPITS
with the protocol originated by KME.
2) Reception signal path
24
Содержание KX-T7453
Страница 7: ...5 IC DATA 5 1 IC1 7 ...
Страница 10: ...10 ...
Страница 15: ...15 ...
Страница 21: ...The reset signal is negledted 21 ...
Страница 26: ...8 2 THE LCD DOES NOT OPERATE 26 ...
Страница 28: ...8 5 SPEAKER PHONE TROUBLE 8 6 TONE DIAL TROUBLE 8 7 HANDSET TROUBLE 28 ...
Страница 29: ...9 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 29 ...
Страница 33: ...13 ACCESSORIES AND PACKING MATERIALS 33 ...
Страница 34: ...14 REPLACEMENT PARTS LIST Note 1 The marking RTL indicates that the Retention Time is limited for this item 34 ...
Страница 39: ... 39 ...
Страница 41: ...41 ...
Страница 43: ...43 ...
Страница 48: ...1 5 2 6 3 7 4 8 ...
Страница 49: ...9 13 10 14 11 15 12 16 ...
Страница 50: ...17 21 18 22 19 23 20 24 ...
Страница 51: ...33 34 35 36 25 32 ...
Страница 57: ...SW301 CN301 1 2 3 ...