Panasonic KX-TS2365RUB Service Manual ▷ View online
12 BLOCK DIAGRAM
Mic
Speaker
Head Set
LCD
IC801
IC601
Q421, Q424
CPU
Handset
AMP
Receiving
Transmit
AMP
Dial
Q108
AMP
Q109
Q405, Q406
T1
Q101, Q103
Ringer
D1
D101
IC201
IC1
Handset
AMP
Sending
Tone
Detection
Mic
Speaker
Mic
Speaker
H/S
Data
T
LINE
C1
R1
R
SP-PHONE
AMP
Key Board
Switch
KX-TS2365RUB: BLOCK DIAGRAM
IC303
Q302
CPU
(Reset)
IC304
3.7V
IC302
4.5V
Battery
Battery
Low
CPU
(
(
KX
-T
S
236
5RUB
21
13 CIRCUIT OPERATION
13.1. Bell Detector Circuit
When the bell signal is input between T/R, the signal are outputted at the speaker via the following path: Tel line
→
R1/C1
→
D1
→
Pin 1 of IC1
→
Pin 8 of IC1
→
C6
→
T1
→
C625
→
Speaker
13.2. Line Interface
In talk status, L1 RLY output from pin 25 of IC801 changes to low level, causing Q103, Q101 to turn on and resulting in a line
loop.The loop current flows from D101(+)
loop.The loop current flows from D101(+)
→
Q101
→
Q108
→
R124
→
D106 in that order, A pulse signal that repeated
switches between high and low logic is output from pin 26 of the CPU.This switches the line loop on and off, generating the dial
pulse signal.
pulse signal.
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KX-TS2365RUB
13.3. Speakerphone Circuit
13.3.1.
Function
The circuit controls the automatic switching of the transmitted and received signals, to and from the telephone line, when the
unit is used in the hands -free mode.
unit is used in the hands -free mode.
13.3.2.
Circuit Operation
The speakerphone can only provide a one-way communication path.
In other words, it can either transmit an outgoing signal or receive an incoming signal at a given time, but cannot do both
simultaneously. Therefore, a switching circuit is necessary to control the flow of the outgoing and incoming signals.
simultaneously. Therefore, a switching circuit is necessary to control the flow of the outgoing and incoming signals.
This switching circuit is contained in IC601 and consists of a Voice Detector, TX Attenuator, RX Attenuator, Comparator and
Attenuator Control. The circuit analyzes whether the TX(transmit) or the RX(receive) signal is louder, and then it processed the
signals such that the louder signal is given precedence.
Attenuator Control. The circuit analyzes whether the TX(transmit) or the RX(receive) signal is louder, and then it processed the
signals such that the louder signal is given precedence.
The Voice Detector provides a DC input to the Attenuator Control corresponding to the TX signal.
The Comparator receives a TX and a RX signal, and supplies a DC input to the Attenuator Control corresponding to the RX
signal.
signal.
The Attenuator Control provides a control signal to the TX and the RX attenuator to switch the appropriate signals on and off.
The Attenuator Control also detects the level of the volume control to automatically adjust for changing ambient conditions.
The Attenuator Control also detects the level of the volume control to automatically adjust for changing ambient conditions.
1. Transmission signal path:
The input signal from the microphone is sent through the circuit via the following path:MIC
→
Pin 9 of IC601
→
Pin 10 of
IC601
→
Pin 3 of IC601
→
Pin 4 of IC601
→
R601
→
C602
→
Q108
→
Tel line.
2. Reception signal path:
Signals receive from the telephone line are outputted at the speaker via the following path:Tel line
→
Q108
→
Q109
→
C112
→
R600
→
C603
→
Pin 27 of IC601
→
Pin 26 of IC601
→
Pin 19 of IC601
→
Pin 15 of IC601
→
Speaker.
3. Transmission/Reception switching
The comparison result between TX and RX outputs as a DC level of Pin 25 of IC601.TX level is high ...... Pin 25 = Pin 21
- 6mVRX level is high ...... Pin 25 = Pin 21 - 150mVComparator output is connected to the attenuator control inside of IC601.
- 6mVRX level is high ...... Pin 25 = Pin 21 - 150mVComparator output is connected to the attenuator control inside of IC601.
4. Voice detector
The output of the mic amp (Pin 10 of IC601) is supplied to Pin 13 of IC601 as a control signal for the voice detector.
5. Attenuator control
The attenuator control detects the setting of the volume control through Pin 24 of IC601 to automatically adjust for changing
ambient conditions.
ambient conditions.
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KX-TS2365RUB
13.4. Telephone Line Interface
13.4.1.
Circuit operation
·
On hook
Q101 is open, Q101 is connected as to cut DC loop current and cut the voice signal.
·
Off hook
Q101 turns on thus providing an off-hook condition (active DC current flow through the circuit) and the following signal flow id
for the DC loop current. T
for the DC loop current. T
→
POS101
→
D101
→
Q101
→
Q108
→
R124
→
D106
→
D101
→
R
·
The receiving signal flows:
TEL line
→
POS101
→
Q101
→
C113
→
R125
→
C108
→
Q109
→
Q405
→
Q406
→
Speaker
·
The transmission signal flows
Mic
→
Q421
→
Q424
→
C435
→
R437
→
Q108
→
Pos101
→
Tel Line
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KX-TS2365RUB
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