JPH05292500A - Catv transmission line monitoring system - Google Patents

Abstract

PURPOSE:To make a CATV center detect the service life of a battery regularly. CONSTITUTION:The CATV center prepares power source monitoring control data to monitor the service life of a battery 19, and transmits it as a frequency division multiplex signal to a power source supplier 1. A control circuit 17 of the power source supplier 1, in a state which a commercial AC voltage is not turned OFF, by the power source monitoring control data to monitor the service life of the battery 19, supplies a switching signal g1 of a high level to a switch 31 and turns the switch 31 to an OFF state. When the switch 31 is turned to the OFF state, a DC voltage is not supplied from a charging circuit 18 to the battery 19 so that the voltage value of a voltmeter 22 starts to lower immediately after the commercial AC voltage is turned OFF and becomes 0V after a prescribed time. The CATV center can detect and discriminate the service life of the battery by detecting the relation between a voltage drop and the time by the voltage value of the voltmeter 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CATV transmission line monitoring system for monitoring the state of a power supply device on a transmission line,
In particular, it relates to a CATV transmission line monitoring system capable of monitoring the state of the battery of the power supply.

[0002]

2. Description of the Related Art In recent years, cable television (hereinafter referred to as C
The system called ATV) is becoming popular. CATV
The system connects the operator and each subscriber with a CATV transmission line, and supplies a program through this cable. The CATV transmission line includes a cable, an amplifier, a power supply device that supplies power to the amplifier, and the like. In such a CATV system, these CATV
In order to prevent the program supply from being stopped due to a failure of the equipment on the transmission line, the status of the power supply unit on the CATV transmission line is monitored C
An ATV transmission line monitoring system has been introduced.

FIG. 4 is a block diagram showing a CATV system into which such a conventional CATV transmission line monitoring system has been introduced.

In FIG. 4, reference numeral 50 denotes a CATV center. The CATV center 50 has a head end 51 that outputs a television signal, a computer 52 that outputs information data, and an analog data information from the computer 52. A modem 53 for converting into a signal and an adder 54 for mixing an analog signal from the modem 53 and a television signal from the head end 51 are provided.

The CATV center 50 will be described in more detail. The headend 51 is composed of terrestrial retransmitting equipment, satellite broadcasting, independent broadcasting transmitting equipment, and the like. Various types of television modulators are provided inside the headend 51. A video signal
M-VSB (amplitude modulation vestigial sideband) signal, voice signal F
The signal converted into the M signal, that is, a television signal of a predetermined channel is converted.

The computer 52 includes address data of each subscriber's terminal device, program contract information including data for operating a descrambler according to the contract content, information data of each subscriber terminal device transmission path information, image quality correction data, and the like. Is stored, and these information data are output as needed. The computer 52 also stores power supply monitoring control data for monitoring the power supply device 61, which will be described later, and outputs the power supply monitoring control data as needed.

The modem 53 frequency shift modulates the information data and the power supply monitoring control data from the computer 52 and converts them into analog signals. The adder 54 mixes the analog signal from the modem 53 and the television signal from the headend 51 to generate a CA as a frequency division multiplexed signal.
It is led to the output terminal 55 of the TV center 50.

The frequency division multiplexed signal from the output terminal 55 is supplied to a plurality of terminal devices (not shown) via the transmission line 60. The transmission line 60 includes a plurality of power supply devices 61, 61.
... supply power to a plurality of amplifiers 62, 62, and these amplifiers 62, 62 ... branch the frequency division multiplexed signal to supply to a plurality of terminal devices.

The modem 53 is supplied with an analog measurement signal from a power supply 61, which will be described later. As a result, the modem 53 converts the analog measurement signal into measurement data and supplies it to the computer 52. The computer 52 grasps the state of the power supply device from the measurement data.

FIG. 5 is a circuit diagram showing the power supply 61 of FIG.

In FIG. 5, the input terminals 71 and 72 of the power supply 61 are a pair of input terminals to which the commercial AC voltage from the commercial AC power source is introduced. The input terminal 71 is connected to the input terminal 72 via the primary coil C1 of the transformer 73. One end and the other end of the secondary coil C2 of the transformer 73 are connected to the input terminals a1 and a of the changeover switch 74, respectively.
2 and the input terminal pair of the rectifier circuit 75. As a result, the transformer 73 steps down the commercial AC voltage, creates an AC voltage for supplying the amplifier,
The voltage is applied between the input terminals a1 and a2 of the changeover switch 74 and is led to the rectifier circuit 75.

The rectifier circuit 75 rectifies an AC voltage from one end and the other end of the secondary coil C2 of the transformer 73 to generate a DC voltage between the output terminal pair and one input terminal of the rectifier circuit 75. Is supplied to the input detection circuit 76. The input detection circuit 76 is the rectifier circuit 7
By detecting the voltage applied to one of the input terminals of No. 5, it is detected whether or not the AC voltage is supplied to the rectifier circuit 75, and it is detected that the AC voltage is supplied to the rectifier circuit 75. Is supplied to the control circuit 77, and when it is detected that the AC voltage is not supplied to the rectifier circuit 75, the low level detection signal a3 is supplied to the control circuit 77. Charging circuit 78
Smooths the DC voltage from the rectifier circuit 75 to generate a smoothed DC voltage between the output terminal pair, and the positive terminal (+) of the battery 79 is output from the output terminal pair.
The battery 79 is charged by applying a smoothed DC voltage between the negative electrode terminal and the negative electrode terminal (−). Battery 7
The positive input terminal and the negative input terminal of the inverter circuit 80 are connected to the positive terminal (+) and the negative terminal (−) of the battery 9, respectively.
And a DC voltage generated between the negative terminal (-) and the negative terminal (-) is supplied to the inverter circuit 80. The inverter circuit 80 creates an amplifier supply AC voltage from the DC voltage from the battery 79 and guides it from the output terminal pair to the input terminals b1 and b2 of the changeover switch 74.

The changeover switch 74 is controlled by the changeover control signal b3 from the control circuit 77. When the changeover control signal b3 is at a low level, the input terminals a1 and a are selected.
2 is selected and connected to the common terminals c1 and c2, and when the switching control signal b3 is at high level, the input terminals b1 and b
2 is selected and connected to the common terminals c1 and c2.

The voltmeter 82 detects the voltage between the positive terminal (+) and the negative terminal (-) of the battery 79, and outputs the voltage detection signal c3 of this detection result to an analog / digital conversion circuit (hereinafter referred to as A / D). Conversion circuit) 81.

The voltmeter 83 detects the voltage between the common terminals c1 and c2 of the changeover switch 74 and supplies the voltage detection signal d3 as the detection result to the A / D conversion circuit 81. A /
The D conversion circuit 81 receives the detection signal c from the voltmeters 82 and 83.
3, d3 are converted into digital signals e3, f3, respectively, and supplied to the control circuit 77.

Common terminals c1 and c of the changeover switch 74
2 is connected to the power output terminals 84 and 85 of the power supply 61. The power output terminal 84 is connected to the reference potential point, and the output terminal 85 is connected to the connection point between the output terminal 55 of the CATV center 50 and the amplifier 62 shown in FIG.

The modem 86 is connected to the power output terminal 85 and communicates with the CATV center 50.
That is, the modem 86 converts the frequency division multiplexed signal from the CATV center 50 into power supply monitoring control data and supplies the data to the control circuit 77, and converts the measurement data from the control circuit 77 into an analog measurement signal to output to the CATV center 50. Supply to.

When the detection signal a3 from the input detection circuit 76 becomes high level, the control circuit 77 supplies the low level changeover control signal b3 to the changeover switch 74 and inputs it to the common terminals c1 and c2. The terminals a1 and a2 are connected to each other, and the AC voltage from the secondary coil C2 of the transformer 73 is output to the power output terminals 84 and 85 of the power supply 61. Further, when the detection signal a3 from the input detection circuit 76 becomes low level, the control circuit 77 supplies a high-level control signal to the changeover switch 74 to input the common terminals c1 and c2 to the input terminals b1 and b1. b2 is connected to each other, and the AC voltage from the inverter circuit 80 is output to the power output terminals 84 and 85 of the power supply 61. Further, the control circuit 77, based on the power supply monitoring control data from the modem 86, outputs the digital signal e from the A / D conversion circuit 81.
3, f3 is converted into measurement data and supplied to the modem 86. Thereby, the modem 86 converts the measurement data indicating the voltage values of the voltmeters 82 and 83 from the control circuit 77 into an analog measurement signal and supplies the analog measurement signal to the CATV center 50.

In such a conventional power supply device 61,
When the commercial AC voltage is not cut off, the input detection circuit 7
The detection signal a3 from 6 becomes high level, and the control circuit 7
7 supplies the changeover switch 74 with a low level changeover control signal b3. The changeover switch 74 connects the input terminals a1 and a2 to the common terminals c1 and c2, respectively, and connects the transformer 7 between the power output terminals 84 and 85 of the power supply 61.
3 secondary coil C2 is connected. As a result, the AC voltage from the secondary coil C2 of the transformer 73 is applied to the power supply 61
Output to the power output terminals 84 and 85 of the amplifier 6 of FIG.
2 is supplied as a power supply voltage. In this state, the modem 8
6 converts the frequency division multiplexed signal from the CATV center 50 into power supply monitoring control data and supplies it to the control circuit 77. Therefore, the control circuit 77 sends to the modem 86 the measurement data indicating the voltage values of the voltmeters 82 and 83. Then, the modem 86 converts the measurement data into an analog transmission signal and supplies the analog transmission signal to the CATV center 50. In this case, since the voltage values of the voltmeters 82 and 83 are constant, the CATV center 50 confirms that the power supply device 61 is operating normally.

When the commercial AC voltage is cut off, the detection signal a3 from the input detection circuit 76 becomes high level,
The control circuit 77 supplies the changeover switch 74 with a high-level changeover control signal b3. The changeover switch 74 is
The input terminals b1 and b2 are connected to the common terminals c1 and c2, respectively, and the output terminal pair of the inverter circuit 80 is connected to the power supply output terminals 84 and 85 of the power supply device 61. As a result, the AC voltage of the inverter circuit 80 to which the power supply voltage is supplied by the battery 79 is output to the power supply output terminals 84 and 85 of the power supply device 61 and supplied to the amplifier 62 of FIG. 4 as the power supply voltage. In this state, the modem 86 is
Since the frequency division multiplexed signal from the center 50 is converted into power supply monitoring control data and supplied to the control circuit 77, the control circuit 77 causes the voltmeter 8 excluding the moment when the commercial AC voltage is cut off.
The measurement data indicating the voltage value of 2,83 is supplied to the modem 86, and the modem 86 converts the measurement data into an analog transmission signal and supplies the analog transmission signal to the CATV center 50. In this case, since the DC voltage is not supplied to the battery 79 from the charging circuit 78, the voltage value of the voltmeter 82 starts decreasing immediately after the commercial AC voltage is cut off, and becomes 0 V after a predetermined time. The voltage value of the voltmeter 83 shows the same value as before the commercial AC voltage was cut off for a predetermined time except for the moment when the commercial AC voltage was cut off, and the voltage value of the voltmeter 82 began to drop when it fell below the predetermined value. Then, it becomes 0V after a predetermined time. CATV center 50
When the voltage value of the voltmeter 82 starts decreasing, it is confirmed that the commercial AC voltage is cut off, and when the voltage value of the voltmeter 83 starts decreasing, the battery 79 is out of order. To confirm.

The CATV center 50 also includes a voltmeter 82,
When the voltage value of at least one of 83 is drastically decreased, it is confirmed that the power supply 61 is abnormal.

As described above, in the conventional CATV transmission line monitoring system of the related art, the state is confirmed in the power supply 61. Here, the battery 79 has a life and must be replaced regularly even if it is not used. However, in the power supply 61 of FIG. 5, when the commercial AC voltage is not cut off, the voltage from the charging circuit 78 is the battery 7
Since it is applied between the positive electrode terminal (+) and the negative electrode terminal (−) of 9, the voltage value of the voltmeter 82 is constant regardless of the life of the battery 79, and the CATV center 50 uses the life of the battery 79. Cannot be detected.

[0023]

As described above, in the conventional CATV transmission line monitoring system, since the voltage from the charging circuit is applied to the battery when the commercial AC voltage is not cut off, the voltage of the battery is reduced. The voltage value of the voltmeter to detect is constant regardless of the life of the battery,
The CATV center cannot detect the battery life.

The present invention eliminates the above-mentioned problems, and always uses C
CATV where ATV center can detect battery life
An object is to provide a transmission line monitoring system.

[0025]

In the CATV transmission line monitoring system of the present invention, a battery provided on the power supply side, voltage detecting means for detecting the voltage of the battery, and commercial AC voltage are supplied. A charging means for charging the battery by means of the inverter, an inverter circuit provided on the power supply side, for converting the voltage of the battery into an AC voltage for supplying the amplifier on the CATV transmission line as a power supply, and the power supply. And a transformer that is provided on the power supply side to convert the commercial AC voltage into an AC voltage for supplying the commercial AC voltage to the amplifier on the CATV transmission line as a power source. A detection circuit for detecting, and an AC voltage from the inverter and an AC voltage from the transformer, which are provided on the power supply side, based on the detection result of the detection circuit. CATV either one of the
A switch that leads to an amplifier on a transmission path; and a data transmission unit that is provided on the CATV center side and that transmits data for monitoring the life of the battery to the power supply unit.
When receiving data for monitoring battery life from the CATV center side, which is provided on the power supply side, the charging means stops the charging of the battery and the output side of the inverter circuit A CATV transmission line monitoring system comprising: a control circuit that connects a load, converts the voltage detection result of the voltage detection means into measurement data, and supplies the measurement data to the CATV center side.

[0026]

According to such a configuration, the control circuit has the CAT
When receiving data for monitoring the life of the battery from the V center side, the charging means is caused to stop charging the battery and a load is connected to the output side of the inverter circuit. As a result, the battery is discharged.
In this state, the control circuit converts the detection result of the voltage of the voltage detecting means into measurement data and supplies it to the CATV center side, so that the CATV center can always confirm the life of the battery.

[0027]

The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a block diagram of a power supply showing an embodiment of a CATV transmission line monitoring system according to the present invention.

In FIG. 1, the CATV center supplies the same power supply monitoring control data as in the conventional example to the power supply 1, and the life of the battery and the inverter circuit 20.
The power supply monitoring control data for monitoring the state of is supplied to the power supply device 1.

The input terminals 11 and 12 of the power supply 1 are a pair of input terminals to which a commercial AC voltage is introduced. The input terminal 11 is a primary coil C of the switch 31 and the transformer 13.
It is connected to the input terminal 12 through a series connection with 1. The switch 31 is controlled by the control signal g1 from the control circuit 17. One end and the other end of the secondary coil C2 of the transformer 13 are connected to the input terminals a1 and a2 of the changeover switch 14 and the input terminal pair of the rectifier circuit 15, respectively. The AC voltage of the secondary coil C2 of the transformer 13 is rectified by the rectifier circuit 15 and smoothed by the charging circuit 18, and the battery 19 is rectified as a DC voltage.
Is supplied to.

The input detection circuit 16 detects from the voltage applied to one input terminal of the rectification circuit 15 whether or not the AC voltage is supplied to the rectification circuit 15, and the AC voltage is supplied to the rectification circuit 15. If it is detected that the rectifier circuit 15 is not supplied with the AC voltage, the control circuit 17 is supplied with the high level detection signal a1. Is being supplied to.

The battery 19 supplies a DC voltage generated between the positive terminal (+) and the negative terminal (-) to the inverter circuit 20. The inverter circuit 20 includes a control circuit 17
ON / OFF is controlled by a control signal h1 from
When the control signal h1 is at a high level, it is turned on, and an AC voltage for amplifier supply is created from the DC voltage from the battery 19 and guided from the output terminal pair to the input terminals b1 and b2 of the changeover switch 14. In addition, the inverter circuit 20
Turns off when the control signal h1 is at a low level.

The change-over switch 14 is controlled by the change-over control signal b1 from the control circuit 17, and when the change-over control signal b1 is at a low level, the input terminals a1 and a1.
2 is selected and connected to the common terminals c1 and c2, and when the switching control signal b1 is at high level, the input terminals b1 and b
2 is selected and connected to the common terminals c1 and c2.

The voltmeter 22 detects the voltage between the positive electrode terminal (+) and the negative electrode terminal (-) of the battery 19 and supplies the voltage detection signal c1 of this detection result to the A / D conversion circuit 21.

The voltmeter 23 detects the voltage between the common terminals c1 and c2 of the changeover switch 14 and supplies the voltage detection signal d1 as the detection result to the A / D conversion circuit 21. A /
The D conversion circuit 21 converts the detection signals c1 and d1 into digital signals e1 and f1 respectively and supplies them to the control circuit 17.

Common terminals c1 and c of the changeover switch 14
2 is connected to the power output terminals 24 and 25 of the power supply 1.

The modem 26 is connected to the power output terminal 25 and communicates with the CATV center. That is, the modem 26 converts the frequency division multiplexed signal from the CATV center into power supply monitoring control data and supplies it to the control circuit 17, and also converts the measurement data from the control circuit 17 into an analog measurement signal and transmits it to the CATV center. To do.

When the detection signal a1 from the input detection circuit 16 indicates that the AC voltage is supplied to the rectifying circuit 15, the control circuit 17 supplies the changeover switch 14 with the low-level changeover control signal b1. Then, the common terminal c
1 and c2 are connected to the input terminals a1 and a2, respectively, and the inverter circuit 20 is connected to the low-level control signal h.
Supply 1 to turn off. In addition, the control circuit 17
When the detection signal a1 from the input detection circuit 16 indicates that the AC voltage is not supplied to the rectifier circuit 15, a high-level control signal is supplied to the changeover switch 14,
When the input terminals b1 and b2 are respectively connected to the common terminals c1 and c2, a high-level control signal h1 is supplied to the inverter circuit 20 to turn it on. Further, the control circuit 17 supplies the control signal g1 to the switch 31 based on the power supply monitoring control data from the modem 26, and at the same time, the digital signals e1 and f1 from the A / D conversion circuit 21.
Is converted into measurement data indicating the voltage values of the voltmeters 22 and 23 and supplied to the modem 26. Thereby, the modem 26 converts the measurement data indicating the voltage values of the voltmeters 22 and 23 from the control circuit 17 into an analog measurement signal and supplies the analog measurement signal to the CATV center.

The operation of such an embodiment will be described below.

First, operations other than the battery monitoring control will be described.

In operations other than battery monitoring control,
Since the power supply monitoring control data transmitted by the frequency division multiplexed signal from the CATV center does not monitor the life of the battery 19 and the state of the inverter 20, the control circuit 17 causes the switch 31 to switch the low level switching signal g1. Is supplied to turn it on.

When the commercial AC voltage is not cut off, the detection signal a1 from the input detection circuit 16 becomes high level, and the control circuit 17 supplies the low level switching control signal b1 to the switching switch 14 and the inverter circuit. The low-level control signal h1 is supplied to 20. As a result, the changeover switch 14 connects the input terminals a1 and a2 to the common terminals c1 and c2, and the inverter circuit 20 is turned off. Then, the secondary coil C of the transformer 13
The AC voltage from 2 is output from the power supply output terminals 24 and 25. In this state, the control circuit 17 controls the voltmeters 22 and 23.
Is supplied to the modem 26, and the modem 26 is caused to convert the measured data into an analog transmission signal to obtain C
Supply to ATV center. In this case, the voltmeters 22, 2
Since the voltage value of 3 is constant, the CATV center 50 confirms that the power supply device 1 is operating normally.

When the commercial AC voltage is cut off, the detection signal a1 from the input detection circuit 16 becomes low level,
The control circuit 17 supplies a high level switching control signal b1 to the changeover switch 14 and supplies a high level control signal h1 to the inverter circuit 20. As a result, the changeover switch 14 connects the input terminals b1 and b2 to the common terminals c1 and c2, and the inverter circuit 20 is turned on. Then, the AC voltage of the inverter circuit 20 supplied with the power supply voltage by the battery 19 is the power supply 1
Is output to the power supply output terminals 24 and 25 of. In this state,
The control circuit 17 supplies the modem 26 with measurement data indicating the voltage values of the voltmeters 22 and 23 excluding the moment when the commercial AC voltage is cut off, and causes the modem 26 to convert the measurement data into an analog transmission signal. And supply it to the CATV center 50. The CATV center confirms that the commercial AC voltage is cut off when the voltage value of the voltmeter 22 starts to decrease, and the battery 19 fails when the voltage value of the voltmeter 23 starts to decrease. Make sure that

The CATV center has voltmeters 22 and 23.
If the voltage value of at least one of the two drops sharply, it is confirmed that the power supply 1 is abnormal.

Next, the battery monitoring control operation will be described.

The CATV center creates power supply monitoring control data for monitoring the life of the battery 19 and the status of the inverter circuit 20 in a state where the commercial AC voltage is not cut off, and supplies it to the power supply 1 as a frequency division multiplex signal. Send. The modem 26 of the power supply device 1 converts the frequency division multiplexed signal from the CATV center into power supply monitoring control data for monitoring the life of the battery 19 and the state of the inverter circuit 20 and supplies it to the control circuit 17. As a result, the control circuit 17 supplies the high-level switching signal g1 to the switch 31 to turn off the switch 31. In this case, the detection signal a1 from the input detection circuit 16 indicates a low level, and the control circuit 17 supplies the high-level switching control signal b1 to the changeover switch 14 and the high-level control signal h1 to the inverter circuit 20. Supply. The changeover switch 14 connects the output terminal pair of the inverter circuit 20 to the power output terminals 24 and 25 of the power supply device 1, and the inverter circuit 20 is turned on. Then,
Since the DC voltage is not supplied to the battery 19 from the charging circuit 18, the voltage value of the voltmeter 22 starts decreasing immediately after the commercial AC voltage is cut off, and becomes 0 V after a predetermined time.
When the inverter circuit 20 is normal, the voltage value of the voltmeter 23 is measured by the voltmeter 22 except when the commercial AC voltage is cut off.
The voltage value of 1 becomes lower than a predetermined value and starts to decrease, and becomes 0V after a predetermined time. The CATV center detects the relationship between the decrease in the voltage value of the voltmeter 22 and the time, and thus the battery 1
The abnormality of the inverter circuit 20 is detected by determining the life of the voltmeter 9 and detecting the relationship between the decrease of the voltage value of the voltmeter 23 and the time. The CATV center determines the life of the battery 19 and detects the abnormality of the inverter circuit 20, and then,
Power supply monitoring control data for ending the monitoring of the life of the battery 19 and the state of the inverter circuit 20 is created and transmitted to the power supply device 1 as a frequency division multiplex signal. As a result, the power supply 1 returns to the operating state other than the battery monitoring control.

FIG. 2 is a graph showing the relationship between the voltage value V of the voltmeter 22 and the elapsed time t when the commercial AC voltage is cut off when the battery 19 is a good product and when the battery is a life product. The voltage value V is taken and the horizontal axis shows the elapsed time t.

In FIG. 2, the decrease rate of the voltage value V with respect to the elapsed time t is higher when the battery 19 is a good product and when it is a life product. The CATV center can determine the life of the battery based on the difference in the reduction rate.

According to such an embodiment, the CAT is always
Since the V center can detect the life of the battery 19 and the failure of the inverter circuit 20, the battery 19 can be replaced at an appropriate time, and the failure of the inverter circuit 20 can be detected early and repaired. The efficiency of can be increased.

In the embodiment of FIG. 1, in the battery monitoring control operation, when the voltage of the battery 19 is lower than the specified value or when the inverter circuit 20 is out of order, CA
It is possible that the power supply to the amplifier of the TV transmission line is stopped, but in this case, the control circuit 17 supplies the low level switching signal g1 to the switch 31 to turn on the switch 31. Can be solved by

FIG. 3 is a block diagram of a power supply device showing another embodiment of the CATV transmission line monitoring system of the present invention.
The same components as those in the embodiment of FIG. 1 are designated by the same reference numerals and the description thereof is omitted.

In FIG. 3, the power supply 2 of the embodiment of FIG. 1 differs in that instead of providing a switch between the input terminal 11 and the primary coil C1 of the transformer 13, the charging circuit 1
6 and the negative terminal (−) of the battery 19 between the switch 32.
And a switch 33 and a resistor R1 are connected in series between the output terminal pair of the inverter circuit 20, and the switches 32 and 33 are connected to the switching control signals i1 and j of the control circuit 37.
That is, each of them is controlled by 1.

More specifically, the input terminal 11 is
It is connected to the input terminal 12 via the primary coil C1 of the transformer 13 without passing through a switch.

One output terminal of the charging circuit 18 is connected to the positive terminal (+) of the battery 19. Charging circuit 18
The other output terminal of is connected to the input terminal of the switch 32. The output terminal of the switch 32 is connected to the negative terminal (-) of the battery 19. The switch 32 is controlled by the control signal i1 from the control circuit 37. When the switching control signal i1 is at high level, the switch 32 is turned off, and when the switching control signal i1 is at low level, the switch 32 is turned on. The switch 33 has one terminal connected to one output terminal of the inverter circuit 12. Switch 3
The other terminal of 3 is connected to the inverter circuit 1 via the resistor R1.
2 is connected to the other output terminal. Switch 33
Is controlled by the switching control signal j1 from the control circuit 37. When the switching control signal j1 is at high level, it is turned on, and when the switching control signal j1 is at low level, it is turned off. The control circuit 37 is the modem 2
When the power supply monitoring control data from 6 does not indicate that the battery life is monitored, the switches 32 and 33 are supplied with the low level switching control signals i1 and j1, respectively. When the power supply monitoring control data from the modem 26 indicates that the battery life is monitored, the control circuit 37 supplies the high level switching control signals i1 and j1 to the switches 32 and 33, respectively, and at the same time, the inverter circuit. 20 is supplied with a high-level switching control signal b1,
Even when the detection signal a1 from the input detection circuit 16 becomes high level, indicating that the AC voltage is being supplied to the rectifier circuit 15, the inverter circuit 20 is forcibly turned on.

The operation of such an embodiment will be described below.

First, operations other than the battery monitoring control will be described.

In operations other than battery monitoring control,
Since the power supply monitoring control data transmitted by the frequency division multiplexed signal from the CATV center does not monitor the battery 19, the control circuit 37 controls the switch 32,
The low level switching control signals i1 and j1 are supplied to the switch 33 to turn on the switch 32 and switch 3
Turn 3 off.

As a result, the power supply 2 has the same circuit connection as the operation other than the battery monitoring control in the embodiment of FIG. 1, and performs the same operation as that of the embodiment of FIG.

Next, the battery monitoring control operation will be described.

The CATV center creates power supply monitoring control data for monitoring the life of the battery 19 and sends it to the power supply unit 2 as a frequency division multiplex signal in a state where the commercial AC voltage is not cut off. The modem 26 of the power supply 2 converts the frequency division multiplexed signal from the CATV center into power supply monitoring control data for monitoring the life of the battery and supplies it to the control circuit 37. As a result, the control circuit 37 supplies the high-level switching signals i1 and j1 to the switches 32 and 33 to turn on the switch 32,
The switch 33 is turned off. As a result, the output terminal pair of the inverter 20 is connected via the resistor R1, and the battery 19 is not supplied with the DC voltage from the charging circuit 18. Here, the detection signal a1 from the input detection circuit 16 becomes high level, and the control circuit 37 supplies the low level switching control signal b1 to the changeover switch 14, but the inverter circuit 20 supplies the high level control signal h1. To supply. As a result, the changeover switch 14
Connects the secondary coil C2 of the transformer 13 between the power output terminals 24 and 25 of the power supply 2, and the inverter circuit 20 is turned on. As a result, the voltage value of the voltmeter 22 is
The voltage starts to decrease immediately after the commercial AC voltage is cut off, and becomes 0V after a predetermined time. The CATV center determines the life of the battery by detecting the relationship between the decrease in the voltage value of the voltmeter 22 and the time.

According to such an embodiment, the CAT is always
Since the V center can detect the life of the battery 19, the battery 19 can be replaced at an appropriate time, and the efficiency of maintenance work can be improved. Further, in the embodiment of FIG. 1, in the battery monitoring control operation, the changeover switch 14 is
Different from the embodiment described above, the power output terminal 24 of the power supply 2
Since the secondary coil C2 of the transformer 13 is connected between 25, power can be constantly supplied to the amplifier of the CATV transmission line.

[0062]

As described above, according to the present invention, the CATV center can always detect the life of the battery, so that the battery can be replaced at an appropriate time and the efficiency of maintenance work can be improved.

[Brief description of drawings]

 1 Power Supply Device 13 Transformer 14 Changeover Switch 15 Rectifier Circuit 16 Input Detection Circuit 17 Control Circuit 18 Charging Circuit 19 Battery 20 Inverter Circuit 22, 23 Voltmeter 26 Modem 31 Switch

FIG. 1 is a block diagram showing an embodiment of a CATV transmission line monitoring system according to the present invention.

FIG. 2 is a graph showing the relationship between the voltage value and the elapsed time when the commercial AC voltage is cut off when the battery of FIG.

FIG. 3 is a block diagram showing another embodiment of the CATV transmission line monitoring system according to the present invention.

FIG. 4 is a block diagram showing a conventional CATV system.

FIG. 5 is a circuit diagram showing the power supply device of FIG.

[Explanation of symbols]

Claims (1)

[Claims] 1. A CATV transmission line monitoring system for monitoring the state of a power supply device by transmitting and receiving data between a CATV center and a power supply device that supplies power to an amplifier on a CATV transmission line, A battery provided on the power supply side, a voltage detection means for detecting the voltage of the battery, a charging means for charging the battery by supplying a commercial AC voltage, and a power supply side provided on the power supply side. An inverter circuit for converting the voltage of the battery into an AC voltage for supplying the amplifier on the CATV transmission line as a power source; and a commercial AC voltage provided on the power supply side for supplying power to the amplifier on the CATV transmission line. A transformer for converting into an AC voltage to be supplied as a power supply, and whether or not the commercial AC voltage is cut off, provided on the power supply side. And a detection circuit for detecting whether or not it is provided on the side of the power supply, and guides one of the AC voltage from the inverter and the AC voltage from the transformer to the amplifier on the CATV transmission line based on the detection result of the detection circuit. A switch, data transmission means provided on the CATV center side for transmitting data for monitoring the life of the battery to the power supply, and a battery provided from the CATV center on the power supply side When the data for monitoring the life of the battery is received, the charging means is caused to stop charging the battery, a load is connected to the output side of the inverter circuit, and the voltage detection result of the voltage detection means is measured. A CATV transmission line monitoring system comprising: a control circuit that converts the data into data and supplies the data to the CATV center side.