JP2008288015A - Arrester diagnostic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein, in the case of a lightning countermeasure component on a board, the lightning countermeasure component can not be simply replaced, and the manner of deterioration of the lightning countermeasure component is changed depending on the voltage of surge current generated by lightning, whereby the progress of deterioration can not be properly determined by only the number of times of surge current flowing through the lightning countermeasure component. <P>SOLUTION: The deterioration of the lightning countermeasure component is determined by not only the number of flowing times of the surge current but also the voltage of current generated on the secondary side by the surge current, and warning display is executed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lightning arrester diagnostic device provided on a substrate.

  Various lightning countermeasure components are known for protecting electronic devices connected to external power supply lines and signal lines from overvoltage caused by external surges caused by lightning strikes. Such countermeasure parts will gradually deteriorate when a lightning strike occurs, and the discharge voltage will gradually increase, making it no longer useful as a lightning countermeasure part.

A technique for storing and displaying the number of discharges is known in order to investigate the deterioration status of lightning countermeasure components. (For example, Patent Document 1 and Patent Document 2)
JP-A-8-178990 Japanese Patent Laid-Open No. 10-27670

In Patent Document 1 and Patent Document 2, emission of light when discharged is counted using a dedicated component such as a phototransistor. If dedicated parts are used in this way, a space on the substrate is taken, and the cost of the parts increases.
Also, in the determination by the number of discharges, if the surge voltage is high, the deterioration of the lightning countermeasure component is likely to proceed, so an overvoltage current may flow to the secondary side even before the warning display is made. .

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a lightning arrester diagnostic device capable of counting the number of discharges and issuing a warning and replacing a lightning countermeasure component in an existing circuit configuration. To do.

In order to achieve the above object, a lightning arrester diagnostic device of a main invention includes an electronic board having a primary side and a secondary side, and a lightning countermeasure component that discharges a surge current that has entered the secondary side of the electronic device to the primary side. A protection circuit comprising a voltage dividing circuit arranged on the electronic board and having a voltage dividing resistor connected in series between the surge current ingress path and a secondary side ground, and the protection circuit The detection unit detects a voltage between the voltage dividing resistors in the circuit, and the display unit displays a warning when a predetermined condition is reached by the detection unit.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

According to the configuration of the main invention, the electronic substrate has the primary side and secondary side regions, and the lightning countermeasure component discharges the surge current that has entered the secondary side of the electronic device to the primary side. On the other hand, a protection circuit comprising a voltage dividing circuit in which a voltage dividing resistor is connected in series is formed between the surge current approach path and the secondary side ground, and the surge current is discharged to the primary side, The secondary side is protected in consideration of the situation that also flows to the secondary side. In this case, the detection means detects the voltage between the voltage dividing resistors in the protection circuit, and when the detection means reaches a predetermined condition, the display means displays a warning.
With this configuration, it is possible to know in advance the deterioration of lightning countermeasure components on the board, and by displaying a warning, it is possible to know the status of the lightning countermeasure components that are not visible from the outside, and the lightning countermeasure components are degraded. Thus, parts on the board can be replaced before lightning damage occurs.

As an example of the lightning arrester diagnostic device, a series circuit including a Zener diode and a resistor interposed between the voltage dividing resistors and the ground in the protection circuit and having a breakdown at a predetermined voltage is provided, and the detection means includes the Zener diode and The potential at the connection point with the resistor is detected, and the display means displays the warning when the detection means detects that the potential at the connection point has risen above the ground potential.
In such a configuration, not only the number of times but also when the voltage becomes a certain level or more, the detection unit can determine that the predetermined condition has been met and display a warning display on the display unit. For this reason, even if the number of times is small, such as a surge voltage due to a lightning strike with a large voltage, when the deterioration progresses quickly, it is possible to know that the lightning countermeasure component has deteriorated and can be replaced.

As an example of the detection means, a PNP switching transistor connected to the base at the connection point, connected to a collector at a predetermined power supply potential, and connected to the ground via a potential detection resistor is the same as the PNP switching transistor. A configuration having an A / D port to which the connection point between the emitter of the PNP switching transistor and the potential detection resistor is connected, and a microcomputer for detecting the potential at the connection point via the A / D port The display unit may display a warning when the potential detected by the detection unit becomes equal to or higher than a predetermined voltage.
In such a configuration, not only the number of times but also when the voltage becomes a certain level or more, the detection unit can determine that the predetermined condition has been met and display a warning display on the display unit. For this reason, even if the number of times is small, such as a surge voltage due to a lightning strike of a large voltage, when the deterioration progresses quickly, it is possible to know that the lightning countermeasure component has deteriorated and can be replaced. In addition, by using a component that is already used for other purposes on the board, such as a microcomputer, it is not necessary to use another component for this measure, and the cost can be reduced.

As an example of the detection means, a storage means for detecting the number of activations of the lightning countermeasure component and storing the number of times is provided, and the display means is provided when the number of times stored in the storage means exceeds a predetermined number. A warning may be displayed.
With such a configuration, it is possible to determine that the detection unit has reached a predetermined condition based on the number of times, and display a warning display on the display unit.

Further, as a more specific configuration, the lightning countermeasure component is a gap type that is discharged by a discharge element, and the voltage dividing circuit of the protection circuit includes a plurality of resistors having a resistance ratio of 1000: 1, and the protection circuit A series circuit composed of a resistor and a Zener diode which is interposed between a voltage dividing resistor and a ground in the circuit and which is broken down at 3 V, and the detection means is connected to the base at the connection point and has a predetermined power supply potential And a PNP switching transistor having an emitter connected to the ground via a potential detection resistor, and an A / D to which a connection point between the emitter of the PNP switching transistor and the potential detection resistor is connected. And a microcomputer for detecting the number of potential rises at the connection point via the A / D port. When it is detected that the number of times of pressure increase is 10 times or more or that the same voltage has exceeded a predetermined voltage, a warning display is displayed on the display means, and the display means is an OSD display on a television display. These circuits and electronic components may be provided on a television substrate.
Needless to say, the above-described invention configured more specifically has the same effects as the above-described configurations.

Hereinafter, embodiments of the present invention embodied in a television will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a schematic configuration of a television 100 according to the present embodiment. In addition, about the structure which is not directly related to this invention about the said television 100, detailed description and illustration are abbreviate | omitted.

  In the figure, a television 100 extracts a television broadcast signal of a channel selected from a television broadcast signal received by an antenna 11a and outputs the same, and outputs video and audio based on the television broadcast signal. The audio / video processing unit 12 includes a speaker 13 that outputs the audio, a display 14 that displays the video, a microcomputer 15, and a power supply circuit 16 that supplies power to each unit.

  In the above configuration, the microcomputer 15 is electrically connected to each part of the television 100, and the CPU as an internal component of the microcomputer 15 is written in ROM, RAM, etc., which are also components of the microcomputer. The television 100 is controlled according to each program.

  FIG. 2 is a circuit diagram of the lightning arrester diagnostic device on the substrate of the television 100 in this embodiment. The lightning countermeasure component 20, the protection circuit 30, and the microcomputer 15 are included.

The lightning countermeasure component 20 is a gap type, and prevents overvoltage by discharging a surge current between two discharge plates. A surge current generated by a lightning strike enters from the tuner 11 or the like. The lightning countermeasure component 20 discharges and flows such a surge current to the primary side ground 40 without flowing to the secondary side ground 41. As a result, the secondary circuit is protected so that no overvoltage is applied to the secondary ground 41.
The lightning protection component 20 is gradually deteriorated when the discharge is repeated, and the performance decreases. This performance deteriorates depending on the number of discharges, but the deterioration progresses faster when the voltage is higher.

  When the surge current enters from the tuner 11, most of it is discharged due to the performance of the lightning countermeasure component 20 and flows to the primary side ground 40. However, a part of the current also flows to the secondary side ground 41. This current gradually increases when the performance of the lightning countermeasure component 20 deteriorates, and as a result, an overvoltage is supplied and the circuit and components of the television 100 are broken.

  Since such a lightning countermeasure component 20 is provided on the board, the user cannot easily replace it. Therefore, when deterioration progresses, the user needs to take early measures such as contacting the service center.

  In the drawing, the protection circuit 30 includes resistors 31 and 32 constituting a voltage dividing resistor, a Zener diode 33, a grounding resistor 34, a transistor 35, and a potential detecting resistor 36.

  The resistance values of the resistors 31 and 32 are approximately 1000: 1. For this reason, the voltage temporarily applied due to the surge current is also approximately 1000: 1. For example, when an overvoltage of 1000 V is applied, the potential between the resistor 31 and the resistor 32 is about 1 V. Thereby, the voltage applied to the secondary side circuit is lowered, and the secondary side circuit can be protected.

  The voltage divided by the resistor 31 and the resistor 32 and generated between the resistor 32 and the ground is applied to the input port 15a of the microcomputer 15. The microcomputer 15 counts the number of times based on the voltage applied to the input port 15a. When this number exceeds the set number, the microcomputer 15 generates an OSD signal so as to display a warning on the display 14. The number of times of setting is set to a safe number considering that parts replacement at a service center or the like is necessary. If it is about 10 times, since it is usually safe enough, a warning display may be made about 10 times.

  When the voltage divided by the resistor 31 and the resistor 32 is high, the voltage is also reduced by the Zener diode 33. That is, when the divided voltage is larger than the breakdown voltage of the Zener diode 33, the Zener diode 33 breaks down and is prevented from being directly supplied to the input port 15a of the microcomputer 15.

  When the Zener diode 33 breaks down, part of the surge current flows to the ground via the grounding resistor 34. Then, the potential of the grounding resistor 34 rises and a base current flows through the base of the transistor 35. Since the power supply voltage Vcc is applied to the collector of the transistor 35, when a base current is supplied to the transistor 35, a collector-emitter current flows, and this current further flows to the ground via the potential detection resistor 36. . As a result, a voltage drop proportional to the current occurs in the potential detection resistor 36, and the potential can be detected by the input port 15b of the microcomputer 15. When a predetermined voltage is detected at the input port 15b, the microcomputer 15 generates an OSD signal so as to display a warning on the display 14.

  Here, a Zener diode 33 is used that breaks down at about 3V. This is because the set of the television 100 is broken at approximately 6 KV, so that a warning is issued when a current of 3 KV, which is half of that, flows.

  In this way, it is possible to display a warning when not only the number of times but also a predetermined voltage is exceeded. Therefore, when a surge current of a large voltage comes in, a warning can be appropriately displayed even when the lightning countermeasure component 20 has deteriorated quickly.

The determination as to whether or not the voltage exceeds a predetermined magnitude may be made using the voltage input to the input port 15a of the microcomputer 15 without using the current at the breakdown of the Zener diode 33. When the input port 15a is an A / D port, a voltage applied to the input port 15a of the microcomputer 15 can be achieved. When the circuit of the television 100 is determined, the voltage applied to the input port 15a is uniquely determined according to the magnitude of the voltage generated by the surge current. Therefore, the voltage for displaying the warning display may be determined according to the voltage value of the input port 15a when the voltage of the current generated by the surge current exceeds 3 KV.
Since such setting can be executed by causing the microcomputer to read a program, it is not necessary to add parts in hardware, and the value can be easily changed.

FIG. 3 is an example of a warning display.
By displaying such a warning on the display 14, it is possible to prompt the user to contact the service center for parts replacement. This warning display may be always displayed on the display 14 or may be displayed at certain intervals.

  In addition to displaying the warning display, if the warning display is displayed and then standing for a certain period of time or after the warning display is performed, if the lightning countermeasure component 20 further deteriorates, the microcomputer 15 The television 100 may not be turned on by the control. This is because if the power of the television 100 is not turned on, even if the lightning countermeasure component 20 is deteriorated, it is difficult to cause damage due to lightning. In this way, the operation of the television 100 can be stopped before a problem occurs.

  As described above, according to the above-described embodiment, the deterioration of the lightning countermeasure component 20 is determined not only by the number of times the surge current flows, but also by the voltage of the current generated in the secondary-side ground 41 by the surge current. I do.

Needless to say, the present invention is not limited to the above embodiments. It goes without saying for those skilled in the art,
・ Apply by changing the combination of the mutually replaceable members and configurations disclosed in the above embodiments as appropriate.
・ Although not disclosed in the above-described embodiments, members and configurations that are known techniques and can be mutually replaced with the members and configurations disclosed in the above-described embodiments are appropriately replaced, and combinations thereof are changed. And apply
・ Although not disclosed in the above-described embodiments, those skilled in the art may appropriately substitute members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments based on known techniques, Change and apply that combination
Is disclosed as an embodiment of the present invention.

It is a block diagram of the television of a present Example. It is a circuit diagram of the lightning arrester diagnostic apparatus of a present Example. It is an example of the warning display of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11a ... Antenna, 11 ... Tuner, 12 ... Audio-video processing part, 13 ... Speaker, 14 ... Display, 15 ... Microcomputer, 15a ... Input port, 15b ... Input port, 16 ... Power supply circuit, 20 ... Lightning countermeasure component, 30 ... Protection circuit, 31 ... resistor, 32 ... resistor, 33 ... zener diode, 34 ... resistor, 35 ... transistor, 36 ... resistor, 40 ... primary side ground, 41 ... secondary side ground

Claims (5)

An electronic substrate having a primary side and a secondary side;
In a lightning arrester diagnostic device equipped with a lightning countermeasure component that discharges the surge current that has entered the secondary side of the electronic device to the primary side,
A protection circuit comprising a voltage dividing circuit arranged on the electronic substrate and having a voltage dividing resistor connected in series between the surge current approach path and the secondary side ground;
Detecting means for detecting a voltage between the voltage dividing resistors in the protection circuit;
A lightning arrester diagnostic apparatus, comprising: a display means for displaying a warning when a predetermined condition is reached by the detection means. A series circuit consisting of a resistor and a Zener diode, which is interposed between the voltage dividing resistors in the protection circuit and between the ground and breakdown at a predetermined voltage,
The detection means detects a potential at a connection point between the Zener diode and the resistor,
The lightning arrester diagnostic apparatus according to claim 1, wherein the display unit displays the warning when the detection unit detects that the potential of the connection point has risen above the ground potential. The detecting means is
A PNP switching transistor connected to the base at the connection point, a collector connected to a predetermined power supply potential, and an emitter connected to the ground via a potential detection resistor;
The microcomputer has an A / D port to which a connection point between the emitter of the PNP switching transistor and the potential detection resistor is connected, and detects a potential at the connection point through the A / D port. And
The lightning arrester diagnostic device according to claim 1 or 2, wherein the display means displays a warning when the potential detected by the detection means becomes a predetermined voltage or more. The detection means includes a storage means for detecting the number of activations of the lightning countermeasure component and storing the number of times.
The lightning arrester diagnostic apparatus according to any one of claims 1 to 3, wherein the display means displays a warning when the number of times stored in the storage means exceeds a predetermined number. The lightning countermeasure component is a gap type that is discharged by a discharge element,
The voltage dividing circuit of the protection circuit includes a plurality of resistors having a resistance ratio of 1000: 1,
A series circuit composed of a resistor and a Zener diode, which is interposed between the voltage dividing resistors in the protection circuit and between the ground and breakdown at 3 V;
The detecting means is
A PNP switching transistor connected to the base at the connection point, a collector connected to a predetermined power supply potential, and an emitter connected to the ground via a potential detection resistor;
A microcomputer having an A / D port to which a connection point between the emitter of the PNP switching transistor and the potential detection resistor is connected, and detecting the number of rises in potential at the connection point through the A / D port And
When the microcomputer detects that the voltage has increased 10 times or more or the voltage has exceeded a predetermined voltage, it displays a warning on the display means,
The display means is an OSD display on a television display,
2. The lightning arrester diagnostic apparatus according to claim 1, wherein these circuits and electronic parts are provided on a television board.

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