Read Panasonic KX-NT700RU Service Manual 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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