Panasonic KX-TS2368RUW Service Manual ▷ View online
8 BLOCK DIAGRAM
Mic
Speaker
VDD
STOP
Head Set
LCD
IC801
IC601
Q421, Q424
CPU
Handset
AMP
Receiving
Transmit
AMP
Dial
Line Selector SW
Q108
AMP
Q109
LINE1
Hold
LINE2
Hold
Q405, Q406
T21
Q101, Q103
Ringer
D21
D110
IC201
IC22
Handset
AMP
Sending
DC-DC
Converter
Tone
Detection
Mic
Speaker
Mic
Speaker
H/S
T
LINE1
C21
R21
T1
Ringer
D1
IC1
C1
R1
R
D111
Q501~505
Q551~555
LINE1 LED
LINE2 LED
T
LINE2
R
SP-PHONE
AMP
IC303
Q302
CPU
Reset
IC304
3.7V
IC302
4.5V
Battery
Battery
Low
CPU
Key Board
Switch
KX-TS2368RU BLOCK DIAGRAM
K
X
-T
S
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68
R
U
W
9 CIRCUIT OPERATION
9.1. Reset Circuit
9.1.1. Function
This circuit is used for to reset the microcomputer when inserting batteries.
9.1.2. Circuit operation
When the batteries is inserted into the unit, then the voltage is shifted by D304 and power is supplied to the CPUas shown
below.
below.
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KX-TS2368RUW
9.2. Telephone Line Interface
9.2.1. Circuit operation
·
On hook
Q101 is open, Q101 is connected as to cut DC loop current and cut the voice signal.
Q101 is open, Q101 is connected as to cut DC loop current and cut the voice signal.
·
Off hook (in case of Line 1)
In talk status, RLY output from IC801 (45) changes to low level, causing Q103, Q101 to turn on and resulting in a
line loop.
Q101 turns on thus providing an off-hook condition (active DC current flow through the circuit) and the following signal flow is
for the DC loop current.
(Line 1) Tip
In talk status, RLY output from IC801 (45) changes to low level, causing Q103, Q101 to turn on and resulting in a
line loop.
Q101 turns on thus providing an off-hook condition (active DC current flow through the circuit) and the following signal flow is
for the DC loop current.
(Line 1) Tip
→
POS101
→
D110
→
SW110
→
Q101
→
Q108
→
R124
→
D106
→
D110
→
(Line 1) Ring
·
Pulse mode
A pulse signal that repeated switches between high and low logic is output from IC801 (44).
This switches the line loop on and off, generating the dial pulse signal.
A pulse signal that repeated switches between high and low logic is output from IC801 (44).
This switches the line loop on and off, generating the dial pulse signal.
·
The receiving signal flows: (in case of Line 1)
TEL line
TEL line
→
POS101
→
SW110
→
Q101
→
C113
→
R125
→
C108
→
Q109
→
Q405
→
Q406
→
CN401
→
CN402
→
Speaker (H/S)
·
The transmission signal flows: (in case of Line 1)
Mic
Mic
→
Q421
→
Q424
→
C435
→
R437
→
Q108
→
SW110
→
Pos101
→
Tel Line
9.3. Ringer Circuit
When the bell signal is input between telephone line, the signal are output at the speaker via the following path:
Tel line
Tel line
→
R1/C1 [R21/C21]
→
D1 [D21]
→
IC1 (1) [IC22 (1)]
→
IC1 (8) [IC22 (8)]
→
C5 [C35]
→
T1 [T21]
→
C625
→
Speaker
[ ] : in case of Line2
9.4. Tone Detect
This circuit is used to sense the status of the line (busy tone or dial tone) during Auto Redial.
9.4.1. Circuit operation
D110
→
Q101
→
C201
→
R201
→
R205
→
IC201 (5)
→
IC201 (1)
→
D202
→
R208
→
Q201
→
IC801 (50)
When the subscriber hangs-up, check the intermittent tone. If cycle tone is detected, the collector of Q201 goes to a low logic.
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KX-TS2368RUW
9.5. In Use Detector Circuit
9.5.1. Function:
This circuit is designed to automatically provide an LED indication when either one telephone or another telephone which
is connected in parallel across the line is engaged.
is connected in parallel across the line is engaged.
9.5.2. Circuit Description
Q351 turns ON. Then the DC is converted at T351 (9 pin
→
+, 8 pin
→
-). Q352 base becomes (High) and Q352 turns ON.
When Q352 is ON, Q351 base becomes (Low) and Q351 turns OFF. And no electric current flows in the collector of Q351.
Thus Q351 starts oscillating.
In this circumstance voltage is generated at T351 (1, 2) as well as T351 (3, 4).
This output voltage is then rectified by D351 and D352, and smoothed by C351, C352 thus supplied to the IN USE circuits of
Line 1 and Line 2 respectively.
Thus Q351 starts oscillating.
In this circumstance voltage is generated at T351 (1, 2) as well as T351 (3, 4).
This output voltage is then rectified by D351 and D352, and smoothed by C351, C352 thus supplied to the IN USE circuits of
Line 1 and Line 2 respectively.
·
Off hook
When the circuit voltage is less than 18 V (unit and telephone are on-hook).
Telephone Line
When the circuit voltage is less than 18 V (unit and telephone are on-hook).
Telephone Line
→
D110 [D111]
→
D506 [D556] OFF
→
R520 [R570]
→
Q506 [Q506] base a low level.
→
Q506 [Q556] OFF
→
Q507 [Q557] base a high level.
→
Q507 [Q557] ON
→
Q508 [Q560] ON
→
D507 [D557]
→
R821 [R823]
→
LED D803-R [LED D805-R] ON.
·
On hook
When the circuit voltage is more than 18 V (unit and telephone are on-hook).
Telephone Line
When the circuit voltage is more than 18 V (unit and telephone are on-hook).
Telephone Line
→
D110 [D111]
→
D506 [D556] ON
→
R520 [R570]
→
Q506 [Q506] base a high level.
→
Q506 [Q556] ON
→
Q507 [Q557] base a low level.
→
Q507 [Q557] OFF
→
Q508 [Q560] OFF
→
LED D803-R [LED D805-R] OFF.
[ ] : in case of Line2
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KX-TS2368RUW
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