JPH06348983A - Monitoring device using optical transmission line - Google Patents

Abstract

PURPOSE:To provide a monitoring device which can monitor plural areas that may possibly generate the heat on a single thermal fusing type optical transmission line with high using flexibility and performance by providing an optical transmission line which is placed close to a monitored part with its bent middle part and receives the input of light from an optical transmitter means and an optical receiver means which receives the light through an end part of the optical transmission line and converts the light into an electric signal. CONSTITUTION:The light emitted from an LED 11 of an optical transmitter circuit 10 is received through an optical input end 31 of an optical transmission line 30 and then transmitted through an optical output end 32 after passing through the line 30 set along a monitored part. Thus the light of the LED 11 is received at the base of a phototransistor 21 of an optical receiver circuit 20. If this light is attenuated or eliminated at the base of the phototransistor 21, the collector-emitter current is reduced or eliminated or the output is inverted. Therefore the monitoring output 41 has a high potential. Under such conditions, a control signal is acquired to actuate an alarming or protecting circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device using a heat-meltable optical transmission line for preventing an accident caused by an abnormal local temperature rise of electric equipment and the like.

[0002]

2. Description of the Related Art An electric device used as a heat source has an on / off control by a thermostat using a bimetal and a power control using a temperature sensor such as a thermistor and a triac in order to maintain a target temperature. Have been adopted. In addition, as a safety measure when these devices are overheated due to a failure, a metal circuit (temperature fuse) that is melted by a certain amount of heat or more is built in in most cases. In other electric devices, similar temperature fuses may be incorporated in order to avoid the danger of heat generation during abnormal conditions.

However, it is necessary to install the temperature fuse in each part where there is a possibility of abnormal heat generation. Therefore,
If there are multiple parts that may cause abnormal heat generation, it is necessary to incorporate temperature fuses in all of these parts as circuits that are energized, but this is economically and technically easy. Not really. Of course, the use of thermostats or thermistors for this purpose is usually not considered. Especially in high-voltage circuits and high-frequency circuits, insulation and
While satisfying the conditions of extremely high pressure resistance, temperature
It's not easy to take advantage of it. Therefore, there is a demand for a device that can easily and economically detect an abnormality when there are a plurality of portions that may generate abnormal heat.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is a possibility of abnormal heat generation in a single heat-fusible light transmission path without incorporating a temperature fuse or the like in all portions where abnormal heat generation is possible. Monitor all parts to prevent accidents caused by abnormally high temperatures, especially in electrical equipment. It is another object of the present invention to provide a monitoring device that can be applied to prevent accidents due to abnormal heat generation of a high-voltage circuit or a high-frequency circuit by using an optical transmission path that does not need to consider electromagnetic influences.

[0005]

According to another aspect of the present invention, there is provided a monitoring device according to the present invention, wherein light transmitting means and light from said light transmitting means are input to one end, and the light is bent in the middle to be arranged in the vicinity of a monitored portion. And a light receiving means for receiving light from the other end of the light transmitting path and converting it into an electric signal.

[0006]

In normal operation, the light emitted by the light transmitting means is input to the heat-meltable light transmission path, this light is transmitted through the heat-meltable light transmission path, is received by the light receiving means, and is converted into an electrical signal. To be converted. However, in the part where the heat-fusible light transmission path is installed, abnormal heat generation occurs due to device abnormality or high voltage discharge, and the heat-fusible light transmission path is melted or the light transmission path is deformed by external force. Alternatively, when divided, the light from the light transmitting means is blocked and attenuated in the middle of the heat-meltable light transmission path, or does not reach the light receiving means. Therefore, if the transmitted light is attenuated or does not reach the light receiving means, a change occurs in the electric signal converted by the light receiving means, and by detecting this, an abnormality such as heat generation, high voltage discharge, or disconnection occurs. It functions as a monitoring device that can detect.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. 10 is a light emitting diode 11 and a current limiting resistor 1
2 is an example of the simplest optical transmission circuit composed of 2 and the power supply 45 of the optical transmission circuit. The light emitting diode 11, the current limiting resistor 12, and the power supply 45 of the optical transmission circuit are connected in series with each other. 20 is an example of the simplest optical receiving circuit including a phototransistor 21, an emitter resistor 22, an inverting amplifier 23, a time constant capacitor 24, and a power supply 46 of the optical receiving circuit. The positive electrode of the power supply 46 of the light receiving circuit is connected to the collector of the phototransistor 21, and the negative electrode is grounded. The emitter of the phototransistor 21 is grounded via the emitter resistor 22. The emitter of the phototransistor 21 is connected to the input of the inverting amplifier 23, and the output of the inverting amplifier 23 becomes the monitor output 41,
It is used as a signal to activate an alarm device and a protective device. The output of the inverting amplifier 23 is grounded via the capacitor 24. 30 is an optical input end 31 and an optical output end 3
2 is a light transmission path. The light input end 31 is arranged close to the light emitting diode 11, and the light output end 32 is arranged close to the base of the phototransistor 21.

The light emitted by the light emitting diode 11 of the optical transmission circuit is input from the optical input end 31 of the optical transmission path 30 and transmitted through the optical transmission path 30 arranged along the monitored portion. After that, the light is output from the light output terminal 32 and input to the base of the phototransistor 21 of the light receiving circuit 20. In a normal state, light is input to the base of the phototransistor 21 of the light receiving circuit 20 to cause a current to flow between the collector and the emitter, so that the input of the inverting amplifier 23 becomes a high potential H and the output is inverted. The monitoring output 41 has a low potential L. On the other hand, when the light input to the base of the phototransistor 21 of the light receiving circuit 20 is attenuated or extinguished, the current between the collector and the emitter decreases or disappears. Therefore, the input of the inverting amplifier 23 becomes a low potential L and the output is Since it is inverted, the monitor output 41 becomes the high potential H. When the monitoring output 41 is at the high potential H, it becomes a control signal for activating an alarm or a protection circuit. The power supply 45 of the optical transmission circuit and the power supply 46 of the optical reception circuit may be either built-in or externally supplied.

Although it is similar to the conventional temperature fuse in principle, it uses an optical transmission path (optical fiber or the like) in which electrically completely insulated light only passes through the inside. is there. Therefore, it is not necessary to consider the influence electromagnetically, and it is possible to extremely effectively arrange the portion where there is a risk of abnormal heat generation. If a thin optical fiber is used as the light transmission path, it is possible to easily cover all the many dangerous parts. Further, unlike the temperature fuse, it can be easily incorporated into the monitored part later, and the monitored part can be easily changed or added.

In this embodiment, the light transmission path 30 is of a single path, but it may be a light transmission path having a plurality of branched paths, and the light receiving circuit receives the light. The transmitted light may be used as a control signal for an alarm device or a protection circuit without being converted into an electric signal.

FIG. 2 shows a second embodiment in which a monitoring circuit 40 in which the above-mentioned optical transmission / reception circuits are grouped together is incorporated in an electric device 50 to be monitored which may have abnormal heat generation.
Reference numeral 51 is a power supply unit of the electric device. An acrylic resin, a plastic optical fiber, or a silica glass fiber, which is essentially a good electrical insulator, is used for the light transmission path 30 as a heat-fusible light transmission path circuit, and there is a possibility of abnormal heat generation of the electric device 50. Arranged along the part to monitor abnormal heat generation of electrical equipment. The optical transmission path using these electrical insulator members has the characteristic of being melted or cut by high temperature or high voltage discharge, and does not affect the high frequency circuit or the high voltage circuit, and is also affected by the high frequency circuit. Therefore, it can be arranged without considering the electrical characteristics of the high frequency circuit or the like.

From the optical transmission circuit of the monitoring circuit 40 to the optical transmission line 3
The transmitted light is input to the optical input end 31 of 0, is transmitted through the optical transmission path 30, and returns from the optical output end 32 which is the other output end of the optical transmission path 30 to the optical receiving circuit of the monitoring circuit 40. It is arranged as follows. If melting or division occurs due to abnormal heat generation in any part of the optical transmission path 30, the transmitted light input to the optical receiving circuit 20 of the monitoring circuit 40 is attenuated or disappears, so that the monitoring output 41 has a high potential. H,
This serves as a control signal to shut off the power supply unit 51 of the electric device.

FIG. 3 shows a third embodiment in which a monitoring circuit 40 in which the above-mentioned optical transmission / reception circuits are grouped together is incorporated in a high voltage terminal 60 to be monitored which is likely to be discharged or sparked. Reference numeral 61 is a high voltage cable. Light transmission path 30
2 is a heat-fusible light transmission path, which is arranged along a necessary portion of the high-voltage terminal 60 and monitors the discharge of the high-voltage terminal, as in the embodiment of FIG.

As in the embodiment of FIG. 2, the transmitted light is input from the optical transmission circuit of the monitoring circuit 40 to the optical input end 31 of the optical transmission path 30, and this is transmitted through the optical transmission path 30 and the optical transmission path 30. It is arranged so that light returns from the light output end 32 which is the other output end to the light receiving circuit of the monitoring circuit 40. If melting or division occurs due to high heat due to discharge in any part of this light transmission path 30, the transmitted light input to the light receiving circuit 20 of the monitoring circuit 40 is attenuated or disappears, so that the monitoring output 41 is high. The potential becomes H, which becomes a control signal to activate the protection circuit 62 of the high voltage terminal 60. If necessary,
It is recommended to use a high withstand voltage silica glass fiber as the light transmission path 30.

FIG. 4 shows a fourth embodiment in which the monitoring circuit 40 in which the above-mentioned optical transmission / reception circuits are grouped together is incorporated in a general thermal power equipment 70 to be monitored which is likely to generate abnormal heat. It is a fuel supply valve provided in the middle of a pipe for supplying fuel to a thermal power utilizing device. Light transmission path 30
2 is a heat-fusible light transmission path similar to the embodiment of FIG. 2, which is arranged along a necessary portion of the general thermal power utilization equipment 70 and monitors abnormal heat generation of the general thermal power utilization equipment 70.

Similar to the embodiment of FIG. 2, the transmitted light is input from the optical transmission circuit of the monitor circuit 40 to the optical input end 31 of the optical transmission path 30, and this is transmitted through the optical transmission path 30 and the optical transmission path 30. It is arranged so that light returns from the light output end 32 which is the other output end to the light receiving circuit of the monitoring circuit 40. When melting or disconnection occurs in some part of the light transmission path 30 due to high heat due to abnormal heat generation, the light receiving circuit 2 of the monitoring circuit 40.
Since the transmitted light input to 0 is attenuated or extinguished, the monitoring output 41 becomes a high potential H, which becomes a control signal to activate the alarm device 42 and the general thermal power equipment 70.
The fuel supply valve 71 is closed.

As shown in this embodiment, the present invention can be used not only for preventing accidents due to heat generation of equipment that uses electricity, but also for preventing accidents due to all that may cause abnormal heat generation.

FIG. 5 is a fifth embodiment in which the present invention is applied to prevent theft of an exhibit or an exhibit 80 displayed. A coupling tool 81 that is integrated with an exhibit 80 that is being exhibited is provided, and the coupling tool 81 and the light transmission path 30 are engaged with each other. Instead of providing the coupling device 81 that is integrated with the exhibit 80, a through hole may be directly provided in the exhibit 80 so that the light transmission path 30 penetrates through the through hole.

Similarly to the embodiment of FIG. 2, the transmitted light is input from the optical transmission circuit of the monitoring circuit 40 to the optical input end 31 of the optical transmission path 30, and this is transmitted through the optical transmission path 30 and the optical transmission path 30. It is arranged so that light returns from the light output end 32 which is the other output end to the light receiving circuit of the monitoring circuit 40. If any part of the light transmission path 30 is deformed or divided by a force applied from the outside, the light reception circuit 2 of the monitoring circuit 40 is detected.
Since the transmitted light input to 0 is attenuated or extinguished, the monitor output 41 becomes the high potential H, which becomes a control signal to activate the alarm device 42.

In other words, although the degree of freedom that allows the exhibit to be held by hand is provided, if the user takes it away, the light transmission path engaged with the exhibit is deformed or divided. The alarm device 42 is activated to notify that the exhibit is separated from the light transmission path.

[0021]

As described above, according to the heat-fusible light transmission path, a single light transmission path causes abnormal heat generation without incorporating a temperature fuse or the like in all portions where abnormal heat generation may occur. Since it is possible to monitor all the parts that may occur, to detect the abnormal heat generation of electric equipment safely and surely, and to activate the alarm device and the protection circuit, it is possible to prevent accidents. In particular, because it uses a light transmission path that electrically completely insulates light, it is not necessary to consider the influence electromagnetically, and it is possible to use it in a place where high voltage discharge occurs. Can also be used. Further, the manufacturing cost is low, the manufacturing is easy, and unlike the temperature fuse, it can be easily incorporated into the monitored portion later, and the monitored portion can be easily changed or added. further,
For crime prevention, an optical transmission line is attached to an exhibit or the like, and by using this as an extremely thin optical fiber that is inconspicuous, it can be used effectively and aesthetically.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the present invention.

FIG. 2 is a structural explanatory view showing another embodiment when the present invention is carried out as a monitoring device for abnormal heat generation of electric equipment.

FIG. 3 is a structural explanatory view showing another embodiment when the present invention is carried out as a monitoring device for abnormality of a high voltage circuit.

FIG. 4 is a structural explanatory view showing another embodiment when the present invention is carried out as a monitoring device for abnormal heat generation of general thermal power equipment.

FIG. 5 is a structural explanatory view showing still another embodiment in the case where the present invention is applied as a device for monitoring the separation of exhibits.

[Explanation of symbols]

10 ... Optical transmission circuit, 11 ... Emitting diode, 12 ... Current limiting resistor, 20 ... Optical receiving circuit, 21 ... Phototransistor, 22 ... Emitter resistor, 23 ... Inversion amplifier, 24
... condenser, 30 ... optical transmission line, 31 ... optical input end, 32
… Optical output terminal, 40… Monitoring circuit (optical transceiver circuit), 41…
Monitoring output, 42 ... Alarm device, 45 ... Power source for optical transmission circuit,
46 ... Light receiving circuit power supply, 50 ... Electric equipment, 51 Electric equipment power supply section, 60 ... High voltage terminal, 61 ... High voltage cable, 62 ... High voltage terminal protection circuit, 70 ... General thermal power equipment, 71 ... Fuel supply valve, 80 ... Exhibit, 81 ... Coupling device.

Claims (7)

[Claims] 1. A light transmitting means, a light transmission path in which light from the light transmitting means is input to one end, is bent in the middle and is disposed in the vicinity of a monitored portion, and the light transmission path of the light transmission path. A monitoring device comprising: a light receiving unit that receives light from the other end and converts it into an electric signal. 2. The monitoring device according to claim 1, wherein a part of the light transmission path is melted at a temperature equal to or higher than a certain temperature, and a member that attenuates or blocks the transmitted light to be transmitted is used. 3. The member for deforming or dividing a part of the light transmission path by an external force applied from a certain level and attenuating or blocking the transmitted light to be transmitted. The monitoring device described. 4. A light transmission means, a light transmission path formed of a material into which light from the light transmission means is input to one end and melted at a temperature equal to or higher than a certain temperature, and an intermediate portion of the light transmission path. Is equipped with a drive circuit for driving a fluorescent lamp, which is arranged by being routed between components, and a light receiving means for receiving light from the other end of the light transmission path and converting it into an electric signal. Characteristic circuit monitoring device. 5. The light receiving unit turns on the power source of the drive circuit for driving the fluorescent lamp when detecting that the transmitted light is attenuated or blocked by melting a part of the light transmission path. The circuit monitoring device according to claim 4, wherein a detection signal for turning off is output. 6. The light transmitting means, and light from the light transmitting means is input to one end, and is engaged with a monitored object in the middle for detecting departure, a part of which is externally applied. A light transmission path that uses a member that is deformed or divided by the above force and that attenuates or blocks the transmitted light that is transmitted, and light reception that receives light from the other end of the light transmission path and converts it into an electrical signal. A departure monitoring apparatus comprising: 7. The monitoring device according to claim 1, further comprising a terminal for outputting the electric signal to the outside of the optical receiving means of the monitoring device.