JP2860820B2 - Weather sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a weather sensor for detecting three types of states: rain, snow, and no precipitation.

<Conventional technology> Two electrodes are arranged close to each other, and the rain drops due to a decrease in the resistance value when the electrodes are conducted by rainwater or an increase in the capacitance between the electrodes when rainwater adheres. A rainfall detector for detecting is known.

<Problems to be Solved by the Invention> In the above-mentioned rain detector, even if rain has already stopped, it may be erroneously recognized as raining if raindrops are still attached to the detection surface. It is necessary to remove the raindrops with a raindrop removing means such as a heater or a wiper. Also, this type of detector can detect not only rain but also snow,
Since it is difficult to determine whether it is rain or snow, it is not suitable as a general weather sensor, and measures such as the use of a thermometer are required to determine snow.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object thereof is to enable rainfall and snowfall to be separately detected by a device having a simple configuration.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the weather sensor of the present invention has at least two cotton-like electrodes arranged so as to intersect with a slight insulating gap therebetween, and a gap between the two electrodes is provided. A precipitation detector configured to be conducted by the attachment of raindrops or snowflakes, and detecting the conduction state between both electrodes, if it is temporary conduction, it is determined that it is raining, and if it is continuous conduction, it is snowfall. Weather determination means for determining.

Further, a rainfall detecting means is provided for detecting rainfall from a state where temporary conduction between both electrodes of the precipitation detector is repeated.

<Operation> When rain falls on the precipitation detector installed outdoors and water droplets adhere to the intersection of the linear electrodes, the two electrodes are conducted by water droplets, but the water droplets immediately drop and become non-conductive. Return. Also, if snow falls and snowflakes adhere to the intersection of the linear electrodes,
Until the snowflakes melt, the conductive state between the two electrodes is connected, and does not immediately return to the non-conductive state as in the case of a water drop. For this reason, by detecting whether the conduction state between both electrodes is temporary or continuous by the weather determination means,
It is possible to determine whether it is raining, snowing, or nothing.

In the case of rainfall, temporary conduction between the two electrodes is repeated, and the frequency of this repetition substantially corresponds to the amount of precipitation, so that it is possible to detect the amount of rainfall.

<Example> Next, the illustrated example will be described.

FIG. 1 is a block diagram of one embodiment, FIG. 2 is a perspective view of a precipitation detector, FIGS. 3 and 4 are enlarged perspective views of main parts thereof,
FIG. 5 is a block diagram of another embodiment.

2 and 3, 1 is a precipitation detector, 2 is a frame-shaped main body, 3 and 4 are upper electrodes having a structure in which a plurality of linear electrodes are stretched in the vertical and horizontal directions, respectively, and The lower electrode 5 is an intersection of the electrodes 3 and 4, and 6 is a separator provided at the intersection 5. The precipitation detector 1 has a sieve-like configuration as a whole. Is installed outdoors at an inclination angle θ such that the inclination angle becomes high. The separator 6 is a molded product of an insulating resin that is hardly wetted by water, and thus a slight insulating gap is secured between the electrodes 3 and 4. The distance between the electrodes 3 and 4 is selected such that the water droplets adhere to the electrode 5 and the electrodes 3 and 4 are electrically connected to each other. Although the separator 6 is not shown in FIG. 2, the separator 6 may be omitted in practice and the electrodes 3 and 4 may directly intersect with a small gap therebetween.

In FIG. 1, reference numeral 10 denotes a resistor circuit 11, a transistor 12,
A weather signal circuit including an integrating circuit 13, an A / D converter 14, etc., 20 is a rainfall signal circuit including an integrating circuit 21, an A / D converter 22, etc., 25 is a microcomputer, and each A / D converter 14, The output side of 22 is connected to the input terminals 25a and 25b of the microcomputer 25, respectively. Each upper electrode 3 of the precipitation detector 1 is connected to a constant voltage DC power supply as shown in the figure, and a part of the intersection 5a is separated from the other electrode by a diode 7 at the lower electrode 4 and grounded through a resistance circuit 11 through a resistance circuit 11. And each of the remaining intersections 5 is connected to the ground via an integrating circuit 21, and the output of the integrating circuit 21 is input to the A / D converter 22. The amount of conduction of the transistor 12 is controlled by the voltage generated in the resistance circuit 11, and the output is input to the A / D converter 14 via the integration circuit 13.

This embodiment is configured as described above, and when there is no precipitation and the conduction between the electrodes 3 and 4 of the precipitation detector 1 is not performed, the transistor 12 is non-conductive and the power supply voltage is supplied to the A / D converter 14. The digital signal corresponding to the input is input to the microcomputer 25. The input side of the A / D converter 22 is at the ground potential, and a digital signal corresponding to this is input to the microcomputer 25, and it is determined that there is no precipitation.

When rain falls and the raindrops adhere to the electrodes of the precipitation detector 1, especially the upper electrode 3, the water drops flow along the electrode 3 because the electrode 3 is inclined, and when it reaches the intersection 5, the water drops between the electrodes 3 and 4. Although conduction is provided by water droplets, since the separator 6 is made of a material that is not easily wetted by water, the water droplets move along the surface toward the lower electrode 4, and the electrodes 3 and 4 return to a non-conductive state again. Even if the electrodes 3 and 4 directly intersect with a small gap without using the separator 6 as described above, when water droplets of the electrode 3 come into contact with the electrode 4, the surface tension and the action of gravity cause the electrode to drop. Then, the state returns to the non-conductive state immediately between the electrodes 3 and 4.

As described above, the conduction between the electrodes 3 and 4 is temporarily caused by rain, but when the intersection 5a is conducted, the transistor 12 is turned on.
Are conducted, and a current flows. However, a reduction in the input voltage to the A / D converter 14 is suppressed by the integration circuit 13, and the power supply voltage returns to the original power supply voltage after a certain period of time. Also at the intersection 5a with falling snow
When snowflakes adhere to the transistor, the transistor 12 continues to conduct, so that the input voltage of the A / D converter 14 is greatly reduced, and this state is maintained.

Therefore, by determining the change state of the input voltage of the A / D converter 14 by the microcomputer 25, it is possible to determine the rainfall state and the snowfall state, and the result is output from the weather signal output terminal 25c. The reason why the electrode 4 of the intersection 5a is DC-separated from the other electrodes 4 by the diode 6 and the judgment is made by the small number of intersections 5a is that when the number of intersections 5 is large, the rainfall is large. This is to prevent any one of the intersections 5 from being conducted by water droplets, and as a result, the conduction state continues, and it is difficult to distinguish from snowfall.

On the other hand, when the intersection 5 including the intersection 5a is conducted by water droplets, a current flows through the integration circuit 21 of the rainfall signal circuit 20 to be charged, and the A / D increases as the number of conducted intersections 5 and the number of conductions increase. The input voltage of converter 22 increases. Therefore, the microcomputer 25 determines the state of the input voltage, thereby determining the rainfall and outputting the result from the rainfall signal output terminal 25d. Judgment of the rainfall at intersection 5
The more the number is, the more sensitive it can be, so the intersection 5a is also used for this determination.

Note that the state in which snowflakes adhere to the intersection 5 is quite unstable, so the parallel spacing A,
It is desirable that B be appropriately selected so that the snowflakes are caught by the mesh formed by the electrodes 3 and 4 and held securely, as shown in FIG. In the figure, reference numeral 8 denotes a snowflake.

FIG. 5 shows an embodiment in which the weather and the rainfall can be detected by a small number of intersections 5.

As shown in the figure, the intersection 5 of the precipitation detector 1 is connected between a constant-voltage DC power supply and the ground, and the electrode 3 on the power supply side is connected to the base circuit of the transistor 31. Is input to the A / D converter 34 via the integration circuit 33 of the weather signal circuit 32, and the microcomputer 25 determines the state of change of the input voltage to the A / D converter 34, whereby the rainfall state, the snowfall state and The state without precipitation is determined, and the result is output from the weather signal output terminal 25c.

That is, when there is no precipitation, the input voltage of the A / D converter 34 is at the ground potential because the transistor 31 is off, and the high voltage is D converter 34
The highest voltage is input to the A / D converter 34 because the transistor 31 keeps on during the snowfall state.

Further, the output voltage of the transistor 31 is input to the base circuit of the transistor 37 via the differentiating circuit 36 of the rainfall signal circuit 35, and the output voltage of the transistor 37 is supplied to the A /
Input to D converter 39. That is, the transistor 31 is turned on each time the intersection 5 is turned on, and the transistor 37 is turned on accordingly. Therefore, the output voltage of the integrating circuit 38 decreases as the rainfall increases and the number of times of turning on increases. Therefore, the microcomputer 25 determines the state of the input voltage of the A / D converter 39 to determine the amount of rainfall, and outputs the result from the rainfall signal output terminal 25d. Since the output voltage of the transistor 31 is input to the transistor 37 via the differentiating circuit 36, the number of times of conduction of the transistor 31 and therefore the number of times of conduction of the intersection 5 can be reliably detected. Is performed with high accuracy.

Thus, according to this embodiment, both the weather and the rainfall can be detected by the small precipitation detector 1 having a small number of intersections 5.

Further, according to this embodiment, it is possible to detect the presence or absence of snow since it is determined that snow has fallen even when snow has ended and snow remains, and for example, it is possible to obtain a detection result that matches the actual road condition. Therefore, the present invention is suitable for a snowfall sensor for a road snow melting device in a snowy country. In addition, it is also possible to arrange a heating wire or the like as necessary so that the snowfall state is not determined to be falling.

<Effects of the Invention> As is apparent from the above-described embodiment, the present invention detects a state in which the linear electrodes arranged in an intersecting manner are electrically connected by raindrops or snowflakes, and determines that it is raining if the electrical connection is temporary. However, if the conduction is continuous, it is determined that snow falls.

That is, since water does not remain between the linear electrodes due to water droplets, the rain has already stopped, so it is not erroneously recognized that it is raining.Rain drop removing means for preventing this is not required, and the thermometer is not used. It is possible to detect snowfall without using it together. Therefore, a sensor suitable as a general weather sensor can be obtained with a simple configuration.

In addition, a device provided with means for detecting the amount of rain from the repeated state of temporary conduction between the two electrodes of the precipitation detector can detect the amount of rain in the case of rain in addition to the determination of rainfall and snowfall.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a perspective view of a precipitation detector, FIGS. 3 and 4 are enlarged perspective views of essential parts thereof, and FIG. 5 is another embodiment. It is a block diagram. 1 ... precipitation detector, 3 ... upper electrode, 4 ... lower electrode,
5,5a ... intersection, 6 ... separator, 10, 32 ... weather signal circuit, 14, 22, 34, 39 ... A / D converter, 20, 35 ... rainfall signal circuit, 25 ... microcomputer .

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 27/00-27/24 G01W 1/00-1/18

Claims (2)

(57) [Claims] At least two linear electrodes are arranged crossing each other with a slight insulating gap therebetween, and a rain detector configured to conduct between the two electrodes by raindrops or snowflakes. A weather determination means for detecting a conduction state of the sensor, determining that rain is present when the conduction is temporary, and determining snowfall when the conduction is continuous. 2. The weather sensor according to claim 1, further comprising a rainfall detecting means for detecting a conduction state between both electrodes of the precipitation detector and detecting a rainfall from a temporary repetition of conduction.