Panasonic KX-TDA6178X / KX-TDA6178XJ Service Manual ▷ View online
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KX-TDA6178X/KX-TDA6178XJ
5.2.10. Surge Protection
Thyristor is installed between T or R and FG protect from extraneous surge.
5.2.11. Self-Diagnosis
A self-diagnosis relay (RL201A) is installed in A port. In the normal operation mode, it breaks the self-diagnosis relay, and in the
self-diagnosis mode, it makes the self-diagnosis relay. In the self-diagnostic mode, A Tip-Ring is connected to the paired Tip-Ring of
the outside-line card via backboard, and self-diagnosis is feasible.
The self-diagnosis of the outside-line card includes outside call pick up, dial pulse transmission, DTMF transmission, BELL recep-
tion and CPC detection.
self-diagnosis mode, it makes the self-diagnosis relay. In the self-diagnostic mode, A Tip-Ring is connected to the paired Tip-Ring of
the outside-line card via backboard, and self-diagnosis is feasible.
The self-diagnosis of the outside-line card includes outside call pick up, dial pulse transmission, DTMF transmission, BELL recep-
tion and CPC detection.
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KX-TDA6178X/KX-TDA6178XJ
5.2.12. Power Failure Switch Feature
4 out of 24 lines have switching relays (RL200A-D) installed in order to enable the outside call during a power failure. The line con-
nected to the outside call card will be directly connected to the CN201/202 located in forward part of the board via a 4-conductor
TEL cord. In the normal operation mode, it breaks the power failure switching relay, and during a power failure, it makes the power
failure switching relay to initiate Power failure direct connection mode.
nected to the outside call card will be directly connected to the CN201/202 located in forward part of the board via a 4-conductor
TEL cord. In the normal operation mode, it breaks the power failure switching relay, and during a power failure, it makes the power
failure switching relay to initiate Power failure direct connection mode.
5.2.13. Bell Signal Generator and Transmission
In ringing mode, the ringing DC offset and the ringing signal are summed digitally within CODEC in accordance with the pro-
grammed values.
This signal is then converted to an analog signal and applies to the SLIC.
The SLIC amplifies the signal and supplies the line with 75 Vrms.
The bell signal is generated with +80V(VHR) and -55V(VBATH) supplied to SLIC.
grammed values.
This signal is then converted to an analog signal and applies to the SLIC.
The SLIC amplifies the signal and supplies the line with 75 Vrms.
The bell signal is generated with +80V(VHR) and -55V(VBATH) supplied to SLIC.
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KX-TDA6178X/KX-TDA6178XJ
5.2.14. EXT-CID Transmission
This Codec (IC201A-X) generates the extension Caller ID signals (FSK signal) with the CPU control.
The data flow is shown below.
The data flow is shown below.
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KX-TDA6178X/KX-TDA6178XJ
5.2.15. Power Supply Voltage Generator
• Block Diagram
The input from the main power supply is in 2 voltage levels: +15V, +40V.
Since the voltage levels: +15V, +3.3V, +80V, -30V and -55V are required onboard, voltage levels are generated onboard as written
below.
Since the voltage levels: +15V, +3.3V, +80V, -30V and -55V are required onboard, voltage levels are generated onboard as written
below.
• Protection of 3.3V output
The protection circuit consists of an output short protection and an overvoltage protection.
When an output of power supply is short, IC1 works to stop the output as the output short protection.
When +3.3V output become overvoltage caused by Q4 short, it is detected by D7. Q3 is cut by Q2 to shut down the input power
supply as the overvoltage protection.
When an output of power supply is short, IC1 works to stop the output as the output short protection.
When +3.3V output become overvoltage caused by Q4 short, it is detected by D7. Q3 is cut by Q2 to shut down the input power
supply as the overvoltage protection.
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