JPH0210187A - Snowfall detector - Google Patents

Abstract

PURPOSE:To offer the snowfall detector being simple and inexpensive and having high accuracy by deciding a snowfall or not by detecting a difference of outputs of a receiver of optical transmitter and receiver provided, respectively on the top side and the bottom side of a mesh for allowing rain to pass through and obstructing the passing of snow. CONSTITUTION:In case when snow has fallen, the snow stops on a mesh 2 since the dimension of the mesh 2 is smaller than a snow grain. Thereafter, the snow grain becomes a water droplet by a heater which has been formed as one body with the mesh 2, and flows to the lower part along the inclined mesh 2. In this case, there is a large difference between the quantity by which a light beam between a transmitter and a light receiving device 3, 4 of the top side of the mesh 2 is cut off by the snow, and the quantity by which a light beam between a transmitter and a light receiving device 5, 6 of the base side is cut off by the water droplet which is separated from the mesh 2 and drops down due to a fact that the snow is melted, therefore, it becomes a snow detecting output. In such a way, the title detector is simple in its structure and inexpensive, and also, can decide a snowfall with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a snowfall detector, and particularly to a snowfall detector that can be manufactured easily and inexpensively, detects snow with high accuracy, and generates a snowfall detection signal. .

[Conventional technology]

FIG. 3 is a block diagram of a rain/snowfall detector according to the prior art, and in the figure, 10 is a rain/snowfall detection conversion unit;
11 is a light rain/snow receiving plate part, 12 is an electrode heater, 13 is an outer heater, 14 is an electrode, 15 is a thermistor, 16 is a moisture detection board, 17 is a moisture comparison board, 18 is a sub-panel, 19 is a temperature detection board, 20 is a sequence control circuit, 21 is a transformer,
22 and 23 are voltage switching, 24 is electrode heater power, 25 is outer circumferential heater power, 26 is a moisture electrode signal, 27 is a thermistor signal, 28 is a snowfall detection signal, 29 is a rainfall detection signal, 3
0 is a warning, 31 is a moisture signal, and 33 is a rain/snowfall detector. The rain/snow detector 33 is composed of a light rain/snow receiving plate part 11 and a rain/snow detection conversion part 10, and the light rain/snow receiving plate part 11 has an electrode 14° temperature sensor whose resistance value changes when wet with moisture. It consists of a thermistor 15 that melts snow on the electrode, an electrode heater 12 that melts snow on the electrode, and a peripheral heater 13 that melts snow around the electrode. The changes are output as thermistor signals 27 to the rain/snow detection converter 1o. Rain/snow detection conversion unit 10
detects rain/snowfall as follows using the signal from the above-mentioned image receiving/snow receiving plate section 11.

First, the moisture electrode signal 26 from the electrode 4 provided on the image receiving/snow receiving board section 11 is smoothed by the moisture detection board 16 and becomes a moisture signal 31 and output to the moisture comparison board 17. The moisture signal 31 is compared by the moisture comparison board 17 with a specified moisture value set in advance by the sub-panel 18, and if it exceeds the specified moisture value, a relay setting signal is output to the sequence control circuit 20 indicating that moisture is present. On the other hand, the resistance change due to temperature of the thermistor 15 is compared by the temperature detection board 19 with a temperature regulation value set in advance by the sub-panel 18, and the high or low temperature is determined and inputted to the sequence control circuit 10 as a relay contact signal. In the sequence control panel of the sequence control circuit 20, the moisture comparison panel 17.
Based on the signal from the temperature comparison board 19, if the temperature is lower than the specified value and there is moisture, it is determined that it is snowing, and if the temperature is higher than the specified value and there is moisture, it is determined that it is raining, and the signals are output to the outside as the respective snowfall detection signal and rain detection signal. . At the same time, the electrode heater 1
2. A sequence control panel 20 performs control to supply appropriate heater power to the outer circumferential heater 13.

[Problem to be solved by the invention]

As described above, conventional equipment detects snowfall by detecting moisture after melting snow and detecting whether the temperature is higher or lower than a specified value, so from a wood perspective, rain, The determination of snow is determined based on the specified temperature value, which has the problem of increasing the determination error.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a snowfall detector that can be easily and inexpensively formed, has a small snowfall determination error, and has high accuracy.

[Means to solve the problem]

The snowfall detector according to the present invention includes a mesh having a mesh size that allows rain to pass through and prevents snow from passing through, a heater that heats the mesh, and at least one mesh disposed on the top side and the bottom side of the mesh. A pair of optical transmitters/receivers on the top side and a bottom side are installed in a case installed at an angle, and the receiver outputs of the optical transceivers on the top side and the bottom side are differentially amplified to create a comparator. The snow detection signal is output when the output of the differential amplifier is above a certain value.

[Effect]

In the snowfall detector of the present invention, in the case of rain, most of the rain falling from the sky passes through the mesh, whereas in the case of snowfall, the specific gravity of snow is very light, about 1/10 of that of rain. Furthermore, since the size of the mesh is smaller than the snow particles, most of the snow will first stay on the mesh, and then the water droplets that have melted the snow will flow down the mesh as droplets. The amount of water passing through is extremely small. Utilizing these physical properties of snow and rain, we detect the difference between the mesh astronomical measurements and the receiver output of the optical transceiver installed on the ground, and when the difference is large, it is determined that it is snowing. The determination accuracy is improved, and it can be constructed with a simple structure and at low cost.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 (al is a structural perspective view of a snow detecting section installed outdoors in a snowfall detector according to an embodiment of the present invention, and FIG. 1(b) is an electronic circuit attached to the snow detecting section of FIG. 1(a). In the figure, 1 is an outdoor installation box installed outdoors at an angle to the horizontal plane, 2 is a mesh integrated with a heater, and the size of the mesh is determined by the amount of snow at the location where it is installed. The size is slightly smaller than the particle size. 3 is a light transmitter that is installed above the mesh 2 and consists of an ED, etc., and 4 is a light transmitter that is installed above the mesh 2 and consists of a photodiode, a phototransistor, etc. 5 is the same as the light transmitter 3 and is installed on the ground side of the mesh 2. 6 is the same as the light receiver 4 and is installed on the ground side of the mesh 2. The light receiver installed on the ground side, 10 is a drain port. Also, 7 is a differential amplifier that differentially amplifies the output electrical signals of light receivers 4 and 6, and corrects the fixed difference of light receivers 4 and 6. A comparator 8 determines whether the output of the differential amplifier 7 has reached a specified value, and its output is composed of a relay contact, a logical voltage output, or any other suitable element.

Next, the operation in one embodiment of the present invention will be explained based on FIG. First, if it is raining, mesh 2
The amount of rain that blocks the light beam between the transmitter and receiver 5.6 installed on the sky side and the amount of rain that blocks the light beam between the transmitter and receiver 5.6 installed on the ground side are the mesh Although there is a fixed difference in the amount of light scattered by 2, the difference is significantly smaller than in the case of snow, which will be described next. Therefore, even if differential amplification is performed after the above-mentioned fixed difference is corrected by the offset circuit in the differential amplifier 7, the comparator 8 will not determine that the output is significant (that is, it has reached the specified value). . On the other hand, when snow falls, the specific gravity of the snow is about 1/10 that of rain, which is very light, and the dimensions of the mesh 2 are slightly smaller than the snow particles, so it first remains on the mesh 2 for a while.

After that, the heater integrated into the mesh 2 slowly melts it into water droplets, but since the mesh 2 itself is installed with a certain inclination on the horizontal plane, it flows downwards through the mesh 2, and finally It is discharged to the outside through a drain port 9 provided on the lower surface.

In this case, unlike the case of rain described above, the light beam between the transmitter and receiver 3 and 4 on the sky side is blocked by the snow, and the snow melts and water droplets that fall away from the mesh 2 and fall down on the ground side There is a large difference in the amount by which the light beam is blocked between the transmitter and receivers 5 and 6. Therefore, after this difference is differentially amplified by the differential amplifier 6, it is determined to be significant by the comparator and becomes the snow detection output.

In this way, according to the snowfall detector of the above embodiment, snowfall is determined using the physical properties of rain and snow as described above. Snowfall can be determined stably, the determination accuracy can be improved, and since the structure is simple, the device can be manufactured at low cost. Furthermore, the present invention is effective in reducing the heater power of the snow melting device and preventing the antenna device performance from deteriorating when a snow melting device is installed in antenna devices of satellite communication local stations to prevent performance deterioration due to snow accumulation. It is.

Incidentally, the light emitter 3.5 and the light receiver 4.6 of the above embodiment may be provided with hoods to reduce the influence of external light.

In addition, in the above embodiment, mesh 2 is used to separate rain and snow, but the same effect as in the above embodiment can be obtained even if a planar heater with a slit structure having a width smaller than the snow particles is used. . Similarly, the mesh 2 may be made of a perforated plate such as punched metal. Further, in the above embodiment, a mesh having an integrated heater structure is used, but the same effect as in the above embodiment can be obtained even if a heater is installed separately and the snow is melted by a weak hot air method.

In addition, in the above embodiment, the top side is placed across Me Noche 2.

One transmitter/receiver facing each other on the ground side is used as a detector for detecting rain or snow, but these transmitters/receivers are provided in n opposite directions (n is an integer) on each side of the sky and the ground, and their respective outputs are may be differentially amplified as in the embodiment described above, and then determined by the comparator 8. With this method, rain/snow can be determined with higher accuracy than in the embodiment described above.

〔Effect of the invention〕

As described above, according to the present invention, a heater is integrated, a mesh smaller in diameter than snow particles is used, and optical transceivers each consisting of at least one pair of transceivers are installed on the top and bottom sides of this mesh. The receiver outputs of the optical transceivers on the top and bottom sides of the mesh are differentially amplified and sent to the comparator, and the comparator outputs a snow detection signal when the output of the differential amplifier exceeds a certain value. I set it to output, so
Snowfall can be determined by utilizing the physical properties of snow, and snowfall can be determined stably and accurately against external disturbances such as changes in external light. Moreover, since the structure is simple, the device can be formed at low cost, and the reliability is also significantly improved.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view showing the structure of a snowfall detector according to an embodiment of the present invention, FIG. 1(bl) is a block diagram showing an electronic circuit attached to the device of FIG. Fig. 1 is a block diagram for explaining the operation, and Fig. 3 is a block diagram of a snowfall/rainfall detector according to the prior art. In the figure, ■ is a box for outdoor installation, 2 is a mesh integrated with a heater, 3 and 5 are light transmitters, 4 and 6 are light receivers, 7 is a differential amplifier, 8 is a comparator, and 9 is a drain port. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A mesh having a mesh size that allows rain to pass through and prevents snow from passing through, a heater for heating the mesh, and at least one pair arranged on the top side and the bottom side of the mesh, respectively. A casing that has an optical transceiver on the top side and an optical transceiver on the ground side, which consists of a transceiver on the top side, and an optical transceiver on the ground side, and is installed with an inclination, and the receiver outputs of the optical transceiver on the top side and the bottom side are differentiated. A snowfall detector comprising: a differential amplifier that performs dynamic amplification; and a comparator that outputs a snowfall detection signal when the output of the differential amplifier is above a certain value.