JPH05276074A - Monitor device for wire broadcast transmission line - Google Patents

Abstract

PURPOSE:To allow a center side to discriminate the expiration of the service life of a battery by commanding the stop of battery charge of a power supply device for plural branch transmission lines from the center side and allowing the centre side to read a succeeding output voltage level of the battery. CONSTITUTION:A control circuit 28 interrupts a switch 34 in response to a charge stop command via a MODEM 33 to a power supply device of each branch transmission line from a centre side to interrupt the connection of a charging circuit 25 to a battery 26. Then a digital voltage of the battery 26 by a voltage measurement device 31 is sent to the center side via the circuit 28 and the MODEM 33 or the like, a battery voltage of a power supply for a transmission line amplifier is monitored and the center side discriminates the expiration of the battery service life.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable broadcasting transmission line monitoring device suitable for use in, for example, a CATV (cable television) broadcasting system, and more particularly to a power supply device installed on the transmission line. The present invention relates to a battery capable of determining the quality of a battery.

[0002]

2. Description of the Related Art As is well known, in recent years, CATV broadcasting in which a signal transmitted from an operator who is a program supplier is branched into a plurality of cables and transmitted to each subscriber who is a program viewer. The system is becoming widespread. The transmission line of the CATV broadcasting system includes a cable for transmitting a signal, a transmission line amplifier installed at a predetermined position of the cable for compensating the transmission loss of the signal, and a power supply device for supplying power to the transmission line amplifier. It is configured.

FIG. 3 schematically shows the structure of a transmission line network in such a CATV broadcasting system. That is, the signal transmitted from the CATV center 11 on the operator side is transmitted to a plurality of subscribers (not shown) via the cables 13, 13, ... Branched in a dendritic manner by a large number of transmission line amplifiers 12, 12 ,. Are supplied to each.
Further, power supply devices 14, 14, ... For supplying power to the transmission line amplifiers 12, 12, ... Are connected to predetermined positions of the cables 13, 13 ,.

These transmission line amplifiers 12, 12,
.. and the power supply 14, 14, ... Are respectively provided with control, monitoring, and communication functions.
The center computer 15 in the center 11 performs data communication with the transmission line amplifiers 12, 12, ... And the power supply devices 14, 14 ,. Further, the CATV center 11 is provided with a head end 17 which is a facility for transmitting and receiving video and audio signals.

By the way, in the CATV broadcasting system as described above, a particular problem is that the transmission line amplifier 1
, 12, and the power supply devices 14, 14, ... Are out of order, so that the program cannot be supplied to each subscriber. Therefore, conventionally, the transmission line amplifiers 12, 1 are
, And the power supply devices 14, 14, ... Are provided with a monitoring system for monitoring the operating conditions while staying at the CATV center 11 to cope with the above problems.

FIG. 4 shows the configuration of a conventional power supply device in which such a monitoring system is introduced. This power supply device normally lowers a commercial AC (alternating current) voltage applied between the input terminals 18 and 19 with a transformer 20, and uses a switch 21.
And to the cable 13 via the output terminals 22 and 23. The AC voltage stepped down by the transformer 20 is rectified by the rectifier circuit 24 and then used for charging the battery 26 via the charging circuit 25.

Then, due to a power failure or the like, the input terminals 18, 1
When the application of the AC voltage to 9 is stopped, the detection circuit 27 detects that the output voltage level of the rectifier circuit 24 has dropped and generates a detection signal to the control circuit 28. Then, the control circuit 28 switches the switch 21 to the battery 26 side, whereby the DC (direct current) voltage charged in the battery 26 is converted into an AC voltage by the inverter circuit 29, and then the switch 21 and the output terminal 22, It is supplied to the cable 13 via 23.

Here, the voltage level between the output terminals 22 and 23 and the voltage level of the battery 26 are measured by the level measuring devices 30 and 31, respectively. The measurement data output from each of these level measuring devices 30 and 31 is A / D.
After being converted into digital data by the (analog / digital) conversion circuit 32, it is input to the control circuit 28. The measurement data input to the control circuit 28 is transmitted to the center computer 15 of the CATV center 11 by being sent to the cable 13 via the modem 33 and the output terminal 23, and the center computer 15 supplies power to the measurement data. The vessel will be monitored.

However, in the conventional monitoring system for the power supply as described above, the battery 2 is normally used.
Since 6 is always charged, there is a problem that it is impossible to judge whether or not the battery 26 has reached the end of its life even if the voltage level of the battery 26 is monitored by the CATV center 11. There is. That is, the conventional monitoring system cannot judge the life of the battery 26 only by monitoring from the CATV center 11.

[0010]

As described above, the conventional monitoring system for the cable broadcasting transmission line has a problem that it is not possible to determine whether the battery of the power supply has reached the end of its life. ing.

Therefore, the present invention has been made in consideration of the above circumstances, and it is possible to determine whether or not the battery of the power supply device has reached the end of its life by monitoring from the center, which is a very good wired system. An object of the present invention is to provide a monitoring device for a broadcast transmission path.

[0012]

A monitoring device for a cable broadcasting transmission line according to the present invention divides a signal sent from a center into a plurality of lines for transmission, and compensates the transmission loss of the signal on the lines. For a cable broadcasting system having a transmission line amplifier for controlling the transmission line, and a power supply device that selectively supplies the transmission line amplifier with output power of an externally supplied power or a battery charged based on this power as power. There is.

The battery is provided with a first communication means for stopping the charging of the battery of the power supply by a command generated from the center side, and a second communication means for reading the output voltage level of the battery on the center side. It is configured to judge the quality of the battery from the change in the output voltage level of the battery after the charging to the battery is stopped.

[0014]

According to the above configuration, the output voltage level of the battery is read by the center side while the charging of the battery of the power supply is stopped by the command generated from the center side, and the output voltage level of the battery is read. Since the quality of the battery is determined based on the change, it is possible to determine whether the battery of the power supply device has reached the end of its life by monitoring from the center.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1, the same parts as those in FIG. 4 are designated by the same reference numerals. That is, on the output side of the charging circuit 25, a switch 34 for interrupting the supply of the output voltage to the battery 26, that is, for stopping the charging of the battery 26 is interposed. The switch 34 is switched between an on state and an off state by a switching signal generated from the control circuit 28.

In this case, the control circuit 28 normally charges the battery 26 by turning on the switch 34, and the center computer 15 of the CATV center 11 is charged.
When receiving an instruction from the battery 26 requesting monitoring of the life of the battery 26, the switch 34 is turned off and the battery 26
To stop charging.

Here, in the case of a good product whose battery 26 has not reached the end of its life, there is no load when the charging of the battery 26 is stopped, and therefore its output voltage is as shown in the characteristic A of FIG. The rated voltage is maintained over time. On the other hand, in the case of a defective product whose battery 26 has already reached the end of its life, when charging of the battery 26 is stopped, its output voltage drops in a short time as shown by the characteristic B in FIG.

Therefore, when it is desired to determine the life of the battery 26 on the CATV center 11 side, the center computer 15 issues a command requesting monitoring of the life of the battery 26, and then the measurement result of the level measuring device 31 By checking the drop state of the output voltage of the battery 26, it is possible to determine whether the battery 26 has reached the end of its life. The present invention is not limited to the above-described embodiments, but can be variously modified and implemented without departing from the scope of the invention.

[0019]

As described in detail above, according to the present invention,
It is possible to provide an extremely good monitoring device for a cable broadcasting transmission line, which can determine whether or not the battery of the power supply device has reached the end of its life by monitoring from the center.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram shown to explain the operation of the embodiment.

FIG. 3 is a block diagram schematically showing a transmission line network of a CATV broadcasting system.

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

[Explanation of symbols]

11 ... CATV center, 12 ... Transmission line amplifier, 13 ...
Cable, 14 ... Power supply, 15 ... Center computer, 16 ... Communication modem, 17 ... Headend, 18,
19 ... Input terminal, 20 ... Transformer, 21 ... Switch, 2
2, 23 ... Output terminal, 24 ... Rectifier circuit, 25 ... Charging circuit, 26 ... Battery, 27 ... Detection circuit, 28 ... Control circuit, 29 ... Inverter circuit, 30, 31 ... Level measuring device, 32 ... A / D conversion Circuit, 33 ... Modem, 34 ... Switch.

Claims (1)

[Claims] 1. A transmission line amplifier for compensating a transmission loss of a signal on the line, which transmits a signal sent from a center into a plurality of lines, and a power supplied from the outside or this power. A power supply for selectively supplying output power of a battery to be charged based on the power supply to the transmission line amplifier as a power, in a cable broadcasting system according to a command generated from the center side. An output voltage level of the battery from a state in which charging of the battery is stopped, comprising first communication means for stopping charging and second communication means for reading the output voltage level of the battery on the center side. A monitoring device for a cable broadcasting transmission path, which is configured to determine whether the battery is good or bad based on the change of