Panasonic KX-MB1500UCB / KX-MB1500UCW / KX-MB1520UCB / KX-MB1530UCB Service Manual ▷ View online
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KX-MB1500UC/KX-MB1520UC/KX-MB1530UC
6.3.4.
TEL Line Section (KX-MB1520/KX-MB1530 ONLY)
Composed of ITS circuit and NCU circuit.
6.3.4.1.
Description of Block Diagram in Analog Section
Function
The analog section works as an interface between the telephone line and controls ITS circuit and NCU circuit.
The analog section control signals are output from Soc IC300.
The analog section control signals are output from Soc IC300.
Circuit Operation
[NCU]: Network Control Unit the NCU comprises of the following; DC loop forming circuit to connect with the telephone line;
Switching circuit for other interconnected telephones; Bell detection circuit; Remote fax activation circuit.
Refer to NCU Section (KX-MB1520/KX-MB1530 ONLY) (P.31) for the details.
Switching circuit for other interconnected telephones; Bell detection circuit; Remote fax activation circuit.
Refer to NCU Section (KX-MB1520/KX-MB1530 ONLY) (P.31) for the details.
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KX-MB1500UC/KX-MB1520UC/KX-MB1530UC
6.3.4.2.
Block Diagram
㪙㪜㪣㪣
㪈㪌
㪠㪚㪉㪇㪇
㪘㪝㪜㩷㩿㪘㩷㪺㪿㪀
㪝㪞
㪫
㪩
㪉㪅㪌㪭
㪣㪠㪥㪜㪩㪯
㪣㪠㪥㪜
㪫㪯
㪊㪅㪊㪭
㪜㪯
㪫㪩㪣㪰
㪌㪭
㪪㪧
㪤㪬㪫㪜
㪂㪌
㪭
㪚㪛
㪝㪚
㪉
㪝㪚
㪈
㪞㪥
㪛
㪭㪚㪚
㪊
㪋
㪈
㪉
㪎
㪍
㪌
㪏
㪫㪈
㪩㪈
㪠㪚㪊㪇㪇
㪪㪦㪚
㪘㪺㪿㩷
㪠㪥
㪘㪺㪿㩷
㪦㪬
㪫
㪌㪭㪘
㪫㪜㪣㩷㪣㪠㪥㪜
㪜㪯㪫㪅㪫㪜㪣
㪪㪧
㪜㪘㪢㪜㪩
㪈㪉
㪭
㪤㪠㪚㪂
㪤㫀㪺
㪤㪠㪚㪄
㪈㪉
㪭
㪉㪅㪌
㪭
㪚㪥
㪞㪤㪬㪫㪜
㪝㪶
㪤㪬㪫
㪜
㪛㪚
㪫㫉㪸㫅㫊㪽㫆㫉㫄㪼㫉
㪛㪘
㪦㪬
㪫
㪈㪉
㪈㪌
㪠㪚㪉㪇㪊
㪘㪝㪜㩷㩿㪙㩷㪺㪿㪀
㪙㪺㪿
㩷㪠㪥
㪙㪺㪿
㩷㪦㪬㪫
㪈㪉
㪝㪘㪯
㩷㪩
㪯
㪌㪭
㪚㪠㪛
㩷㪩㪯
㪛㪫㪤㪝㪤㪬㪫
㪜
㪛㪘㪦㪬㪫
㪙㪉
㪇
㪪㪧
㪤㪬
㪫㪜
㪝㪉
㪋
㪙㪜㪣㪣
㪣㪉㪊
㪣㪉㪍
㪚㪠㪛
㩷㪩㪯
㪤㪉
㪋
㪝㪘
㪯
㩷㪩
㪯
㪤㪉
㪌
㪝㪶
㪤㪬㪫㪜
㪤㪉
㪍
㪚㪥
㪞㪤㪬
㪫㪜
㪬㪉㪌
㪣㪠㪥㪜㩷㪩㪣㪰
㪭㪉㪍
㪛㪫㪤
㪝㪤㪬
㪫
㪜
KX-MB1520UC/KX-MB1530UC:
MAIN BO
ARD BLOCK DIA
GRAM
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KX-MB1500UC/KX-MB1520UC/KX-MB1530UC
6.4.
NCU Section (KX-MB1520/KX-MB1530 ONLY)
6.4.1.
General
NCU is the with the telephone line. It is composed of Bell detection circuit, Pulse dial circuit, Line amplifier and sidetone circuits. The
following is a brief explanation of each circuit.
following is a brief explanation of each circuit.
6.4.2.
EXT. TEL. Line Relay (RLY100)
1. Circuit Operation
Normally, this relay switches to the external telephone side and switches to the open side while OFF-HOOK.
IC300 (U25) High Level
IC300 (U25) High Level
Q201 ONRLY100 (ON)
6.4.3.
Bell Detection Circuit
1. Circuit Operation
The signal waveform for each point is indicated below. The signal (low level section) input to L23 of SOC(IC300) on the Main
board.
TEL LINE
board.
TEL LINE
PC103 (1, 2 4) IC300 (L23)
6.4.4.
Pulse Dial Circuit
The pulse dial is generated by operating the transistor Q201 while OFF-HOOK (RLY100 ON) condition.
Make state:
IC300 (U25) High Level
Make state:
IC300 (U25) High Level
Q201 ON RLY100 ON
Break state:
IC300(U25) LOW Level
IC300(U25) LOW Level
Q201 OFF RLY100 OFF
6.4.5.
Line Amplifier and Side Tone Circuit
1. Circuit Operation
The reception signal output from the line transformer T100 is input to pin (2) of IC201 via C256, R224 and then the signal is
amplified at pin (1) of IC201 and sent to the reception system at through the LPF.
amplified at pin (1) of IC201 and sent to the reception system at through the LPF.
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KX-MB1500UC/KX-MB1520UC/KX-MB1530UC
6.4.6.
Remote FAX Activation Circuit
1. Function
Another telephone connected to same line activates the unit to the FAX mode by using a DTMF signal.
2. Signal Path
Refer to Check Sheet for Signal Route of CNG/DTMF detection (P.173).
6.4.7.
TAM Interface Circuit
This circuit is to switch between FAX receiving and the external TAM’s message recording automatically.
For details, please refer to TAM Interface Section (P.33).
For details, please refer to TAM Interface Section (P.33).
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