Panasonic KX-NS1000UC (serv.man6) Service Manual ▷ View online
21
KX-NS1000UC
4.5.3.
Output Voltage Section
Describes the circuit that converts main converter output to 15V.
15V Output Voltage Section
(1) 15V Output Converter Section
15V Output Voltage Section
(1) 15V Output Converter Section
The 15V output converter section is a separately-excited chopper step-down converter consisting primarily of IC101, D109,
L101, C121, C122 and R116-R118.
Inputs 32V output described in Part 2 as input power source.
Provides 15V by IC101 and D109 on/off switching and L101/C121, C122 smoothing circuit.
Output voltage is determined by resistance ratio of IC101 and R116-R118.
IC101 oscillation frequency is 300 kHz (typ.).
L101, C121, C122 and R116-R118.
Inputs 32V output described in Part 2 as input power source.
Provides 15V by IC101 and D109 on/off switching and L101/C121, C122 smoothing circuit.
Output voltage is determined by resistance ratio of IC101 and R116-R118.
IC101 oscillation frequency is 300 kHz (typ.).
(2) 15V Output Overcurrent Protection Section
Protection is provided by overcurrent protection circuit in IC101.
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KX-NS1000UC
4.5.4.
Alarm Signal Transmission Section
Part 4 contains a description of the circuit that transmits AC and DC signal.
(1) Alarm Circuit Power Source
(1) Alarm Circuit Power Source
Consisting primarily of Q105 and D114, the alarm circuit power source stabilizes 32V output voltage described in Part 2 to
approximately 27V.
approximately 27V.
(2) AC Alarm Signal Transmission Section
If AC input is detected by the AC voltage detection circuit described in Part 1 (5), Q111 is turned on by secondary side transistor
of PC3 being turned on, and a low signal is transmitted to AC alarm output.
On the contrary, if AC input is not detected, Q111 is turned off by secondary side transistor of PC3 being turned on, and "open"
(open collector output) is transmitted to AC alarm output.
of PC3 being turned on, and a low signal is transmitted to AC alarm output.
On the contrary, if AC input is not detected, Q111 is turned off by secondary side transistor of PC3 being turned on, and "open"
(open collector output) is transmitted to AC alarm output.
(3) DC Alarm Signal Transmission Section
If 15V is outputted properly, IC102 is turned on, relaying to Q108 then to Q106 transmitting low signal to DC alarm output
If there is a problem on 15V output, IC102 will turn off. Q108 and Q106, which in turn transmit open to DC alarm output.
If there is a problem on 15V output, IC102 will turn off. Q108 and Q106, which in turn transmit open to DC alarm output.
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KX-NS1000UC
4.5.5.
Protective Circuit Operation Section
Part 6 provides a description of the overvoltage/overheat protection circuits
(1) Abnormal State Detection Circuit.
(1) Abnormal State Detection Circuit.
If power operation becomes abnormal and a signal is transmitted to the abnormality detection circuit D112, Q112 is turned on,
current flows to the diode of PC2 and is transmitted to the control circuit of the main converter, thereby shutting down main con-
verter operation.
current flows to the diode of PC2 and is transmitted to the control circuit of the main converter, thereby shutting down main con-
verter operation.
(2) Overheat Protective Circuit
When temperature inside the power source rises to an abnormal temperature, the resistance of posister PTC101 rises, transis-
tor Q112 is turned on, and the signalis transmitted to the abnormality detection circuit via D125.
tor Q112 is turned on, and the signalis transmitted to the abnormality detection circuit via D125.
(3) Overvoltage Protective Circuit
If the 15V output is high (overvoltage), D112 detects it and transmit to the abnormal detection circuit via D113.
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KX-NS1000UC
5 Location of Controls and Components
5.1.
Name and Locations
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