Panasonic KX-NT700RU Service Manual ▷ View online
9
KX-NT700RU
4.2.4.
TELEPHONE LINE
4.2.4.1.
Bell signal detection
When TELEPHONE LINE is idle, photo coupler PC604, PC604 are OFF.
When there is an incoming signal from TELEPHONE LINE, the current flows PC605 as in the following way.
When there is an incoming signal from TELEPHONE LINE, the current flows PC605 as in the following way.
RING - L604 - R646 - PC605(1-2) - C628 - R6010 - R651 - R616 - L604 - TIP
: This cause pin4 of PC605 to change the level from High to low.
TIP - L604 - R616 - R651 - R6010 - C628 - PC604(1-2) - R646 - L604 - RING
: This cause pin4 of PC604 to change the level from High to low.
: This cause pin4 of PC605 to change the level from High to low.
TIP - L604 - R616 - R651 - R6010 - C628 - PC604(1-2) - R646 - L604 - RING
: This cause pin4 of PC604 to change the level from High to low.
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KX-NT700RU
4.2.4.2.
DC loop circuit
In the off hook status, PC601 is ON.
DC loop path:
DC loop path:
RING - L604 - D613 - D612 - D604 - Q603(E-C) - Q602(C-E) - R656 - R655 - D604 - R616 - L604 - TIP
At this time, the output of the photo coupler PC605 changes level from High to low.
TIP - L604 - R616 - D604 - R655 - R656 - Q602(E-C) - Q603(C-E) - D604 - D612 - D613 - L604 - RING
At this time, the output of the photo coupler PC604 changes level from High to low.
At this time, the output of the photo coupler PC605 changes level from High to low.
TIP - L604 - R616 - D604 - R655 - R656 - Q602(E-C) - Q603(C-E) - D604 - D612 - D613 - L604 - RING
At this time, the output of the photo coupler PC604 changes level from High to low.
4.2.4.3.
Pulse dial transmission circuit
When the Off hook status, pulse dial transmission is executed by alternating On hook and Off hook.
The status of On hook or Off hook is controlled by the switching transistor Q603.
The status of On hook or Off hook is controlled by the switching transistor Q603.
Pulse dial path:
PB* IC1(13) - PB RA1 - PB CN3(20) - Flat cable - CN301(20) - RA302 - R654 - PC601 - R653 - Q603 (B)
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KX-NT700RU
4.2.5.
Key Input Control Circuit (PANEL BOARD)
The key data is under the matrix control by pin17,18,20,22,24,25-27,29-31 of IC1.
The key information output from COL[4-0] is input into ROW[5-0],when the key is pressed.
The key information output from COL[4-0] is input into ROW[5-0],when the key is pressed.
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KX-NT700RU
4.2.6.
SIGNAL ROUTE
4.2.6.1.
2-party conference call (1 IP call)
4.2.6.2.
2-party conference call (1 TEL call)
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