Schematic Diagram; Circuit Operation; Printed Circuit Board; Component View - Panasonic KX-T7765X Service Manual

KX-T7765X

7 Schematic Diagram

T
M(+)
C1
M1C
100
10V
M(-)
R
7.1.

Circuit Operation

1. Call circuit
Depressing switch S1 causes terminals 1 and 2 to be shorted through R7, therefore a call is detected at the doorphone
adaptor side.
2. Conversation
The transmited voice signal is sent to the doorphone adaptor via the following path.
Mic → Q1, 2 → (Mic amp.) → D1 → T1 → Doorphone adaptor.
The received voice signal is received at the SP via the terminal 1 → T1.
Note:
1. S1: Call switch.

8 Printed Circuit Board

8.1.

Component View

R1
C3
2.2K
M0.0047
C2
0.69V
Q1
50V 1
MIC AMP
R5
22K


5
5
7
5 5
a a
&
6 


7
6 
 
S(-)
4
3
R3
RECT
1K
R2 R8
2.2K 150
2.75V
1.37V
Q2
0.08V
MIC AMP 0.73V
C4
R4 R6
10
150
270
16V
KX-T7765X SCHEMATIC DIAGRAM
(
(
4
5
4
&
5
&
&
&
5
0  0 
&
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8
SP
S(+)
T1
6
2 1
D1
R7
1K
C5
C6
M0.047
1
50V
(NP)
S1
Call SW
3483=
3E)
5
5
6
'