Panasonic KX-F1200 Service Manual And Technical Manual page 135

KX-F1200
9. IN-U_- U_" Ii=UT CIRCUIT
1) Function
In-use detect circuit detects the lower voltag_ ut telephurle line, _nd re_ugn,zes that thu paralleled telephone is OFF-HOOK.
Then, CPU lights, the IN-USE LED on operation panel to red.
The different voltage is detected at "OO" and "PBX" set in user mode #28.
CO mode detects ON-HOOK if the voltage is more than 30V and detects OFF-HOOK if it is less than 24V. ]
PBX mode detects ON-HOOK if the voltage is more than 21V and detects OFF-HOOK if it is less than 15V.J
2) Circuit operation
(1) Settings: Line1, CO mode
Line1 T-R (48V) _ R63 _ ZD9 _ O7 _ Q8 _ PC11 _ INUSE L1
(ON) (ON) (OFF)(OFF) (High)
II
IParallel Tel ON-HOOKI
Line1 T-R (16V) --, R63 -4' ZD9 --* Q7 --, Q8 --, POll --, INUSE L1
(OFF) (OFF) (ON) (ON) (Low)
II
IParallel Tel OFF-HOOKI
(2) Settings: Line2, PBX mode
Line2 T-R (24V) --* R70 --, PC10 ---,ZD12 --, Q9 -', Q10 ---, PC12 ---, INUSE L2
(ON) (ON) (ON) (OFF) (OFF) (High)
II
A/B L2=High _ IParallel Tel ON-HOOKI
Line2 T-R (9V) --, R70 --, PC10 --, ZD12 --, Q9 --, Q10 --, PC12 --, INUSE L2
(ON) (OFF) (OFF) (ON) (ON) (LO..W)
A
II
A/B L2=High T IParallel Tel OFF-HOOK I
Circuit Diagram
*bVL) +SVD
t
R69[
H79_-_lk __.Q24 C222 ' - _'_-_J3 6 D3
o..°, o,:t,o c"
PCl 1 R661
4_PC12
3_"_2 R73f
L. N_L2 (_
+5VD
R651 R63
+I VD
R72 ,: R70
REC 1
REC 2
o
0
Line 2
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