Panasonic KX-TS2350UAJ / KX-TS2350UAS / KX-TS2350UAT Service Manual ▷ View online
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KX-TS2350UAJ/KX-TS2350UAS/KX-TS2350UAT
4 Technical Descriptions
4.1.
Block Diagram
MELODY
SEQUENCER
LINE ADAPTATION
POWER EXTRACTION
DC MASK
CONTROL
LOGIC
TONE
GENERATOR
RING
FREQUENCY
DISCRIMINATION
OSC
RAM
MUTE
DIALLER
LINE
CURRENT
SENSE
SOFT CLIP
AGC
V
DD
LI
CI
LS
RI
STB
A
GND
LED
V
DD
V
SS
MO
FCI
HS/DP
LLC
OSC
MFL
M
ODE
C1
C2
C3
C4
R1
R2
R3
R4
M2
M1
RO
CS
IC1
KEY
PAD
R9
sv1
AGND
3.58
ADL
RS
R
T
Q1
Q2
D23
R55
R103
S3
L
H
OFF
D24
R14
IC2
R2
C1
Q8
Q3
Ringer
D2
C34
D17
C22
HS Speake
r
HS MIC
R10
C5
C9
R5
R6
KX-TS2350 BLOCK DIAGRAM
R102
58
1
2
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KX-TS2350UAJ/KX-TS2350UAS/KX-TS2350UAT
4.2.
Circuit Operation
4.2.1.
Telephone Line Interface and Pulse Dial Circuit
When the hook switch SW1 is ON (off-hook), the circuit is closed, and current is supplied to the base of Q2 via the diode bridge
D17 and Q2 is On
D17 and Q2 is On
→ Q1 is ON (OFF-HOOK condition).
Q1 and Q2 are the dial pulse generating circuits, and are driven by the DIALER (IC1), when the DIALER Pin 10 of IC1 is LOW
→ Q2 is OFF and Q1 is OFF (break). If port Pin 10 is HIGH → Q2 is ON → Q1 is ON (make).
→ Q2 is OFF and Q1 is OFF (break). If port Pin 10 is HIGH → Q2 is ON → Q1 is ON (make).
4.2.2.
Tone Dial Circuit
Function:
The tone dialing circuit consists of a DTMF (Dual Tone Multi Frequency) signal generator (outputted from Pin 25 of the IC1) for
tone dialing, and also a circuit for outputting the signal to line.
The DTMF circuit identifies inputs from the 12 keys (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, and #) by means of a total of seven frequencies,
that is four low frequencies (Low group) and three high frequencies (High group).
tone dialing, and also a circuit for outputting the signal to line.
The DTMF circuit identifies inputs from the 12 keys (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, and #) by means of a total of seven frequencies,
that is four low frequencies (Low group) and three high frequencies (High group).
Circuit Description:
When a dial key is pressed, a DTMF signal is output from Pin 25 of IC1 as an analog synthetic wave.
The signal flow to the line is as follows.
Pin 25 of IC1
The signal flow to the line is as follows.
Pin 25 of IC1
→ Q3 → R9 → Q1 → Tel Line.
The DTMF signal is sent to the line via the following path. Q3 is an amplifier which is used to output the signal to line.
Shown below is the signal flow used to output the DTMF signal from the handset as a monitor tone when a dial key is pressed.
Pin 3 of IC1
Shown below is the signal flow used to output the DTMF signal from the handset as a monitor tone when a dial key is pressed.
Pin 3 of IC1
→ VR1 → C15 → Handset Speaker.
The signal combination and frequency corresponding to each dial key is shown on the next page.
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KX-TS2350UAJ/KX-TS2350UAS/KX-TS2350UAT
4.2.3.
Power Circuit and Redial Back-up Circuit
Function:
This set is powered from the line. When it is an OFF-HOOK status, Tel Line
→ D17 → Q1 → R9 → Pin 27 of IC1 (to become the
power supply for IC1 speech network).
The voltage from the line is turned into a constant voltage by D2 and then supplied to the IC1, reset circuit.
Through Tel Line
The voltage from the line is turned into a constant voltage by D2 and then supplied to the IC1, reset circuit.
Through Tel Line
→ R1 → R3 → D17 → R14 to become the power supply for IC1, and the redial Back-up will be done.
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KX-TS2350UAJ/KX-TS2350UAS/KX-TS2350UAT
5 Location of Controls and Components
5.1.
Controls
6 Installation Instructions
6.1.
Connections
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