JPS6020042Y2 - Rainfall detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting rain, particularly to a device for detecting whether it is raining.

Conventionally, this type of device treats rain ice as a conductor, that is, it is configured so that rainwater remains between two electrodes, and when the two electrodes are electrically connected through the rainwater, electricity is applied and an electrical signal is sent. What has been done is known.

However, in such a device, even if the rain stops, as long as rainwater remains between the two electrodes, both electrodes will be energized, and a signal that it is raining will be sent. This is inconvenient.

In order to solve the above-mentioned conventional drawbacks, the present invention provides a capacitor whose capacitance changes as raindrops or their collected water flow passes between electrode plates. To provide a device that accurately detects the beginning, end, and end of descent.

The feature of this invention is that it applies the characteristics of a capacitor, and its principle will be explained below.

As shown in Figure 1a, the capacitor consists of two metal electrode plates A and B that are insulated from each other by a dielectric.

The capacitance of the capacitor C1 in FIG. 1a is given by: C1=E-8/dCF] where E is the dielectric constant.

Also, on the same capacitor as in Fig. 1a, the same electrode X,
A structure in which a conductive substance 2 is inserted between Y is shown in FIG. 1b.

The capacitance of the capacitor in this case is C2=t-5/(d-1)(F), where the area of the conductive material is S: (d) and the width is l (m).

Therefore, the capacitance of the capacitor changes when a conductive substance is introduced between the two electrode plates.

The amount of change (ΔC) in the above example is ΔC=C2−C□=
rS·l/(d-1)d.

By passing raindrops, which are conductive substances, between the two electrode plates, the capacitance of the capacitor is changed.

By converting this change in capacitance into an electrical signal, it is possible to detect when the rain has stopped falling.

The device of the present invention was developed based on the above principle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be explained based on the drawings.

FIG. 2 is a circuit diagram showing an embodiment of the device of the present invention,
In the figure, 1 is a trigger generator, 2.degree.3 is a monostable multi-vibration brake, C.sub.2 is a rain detection capacitor, C2 is a constant capacitor, R1.degree.R2 is a resistor, and 4 is a flip-flop circuit section.

The second monostable multi-by break 2 is the trigger generator 1
The first monostable multivibrator 3 converts the trigger pulse sent from the trigger generator 1 into a pulse proportional to the time constant of C, xR2 and oscillates it. It is configured to oscillate by changing the pulse to a pulse proportional to the time constant.

The pulse of the first multivibrator 3 is sent to the clock of the flip-flop circuit section 4, and the pulse of the second multivibrator 2 is sent to the J and K elements of the flip-flop circuit section 4. It is ready to be sent.

Fig. 3 shows the relationship between the pulses at each point a - e in Fig. 2, where a is the trigger pulse sent from the trigger generator 1, and this pulse is sent to both vibrators 2 and 3 at the same time. Determine the start or end of the pulse emitted from 2 and 3.

b and c are pulses alternately oscillated from the output terminals Q and Q of the vibrator 2.

d is a pulse oscillated from the vibrator 2, and is input to the clock of the flip-flop circuit section 4.

When the pulse of d ends, the signals of J and J are compared by the action of the clock.

Thus, e oscillates only when the signal from J is 111 as determined by the flip-flop circuit.

That is, from the center dot-dashed line m to the left side and the dot-dashed line n
The area on the right side of the arrow indicates the time when it is not raining, and the area between the dashed-dotted lines m and n indicates the time when it is raining.

Next, to explain the operation of this device, for example, when it is not raining right now, the output pulse width from the second multivibrator 2 is 1.0 m5eC (milliseconds), and the output pulse width from the first multivibrator 3 is 1.0 m5eC (milliseconds). Assuming that is 1.5m5eC, when the pulse from the first multi-by-break 3 is cut off, a clock acts and the pulses at J and are compared.

Therefore, if it is not raining, J is '0 (zero l-
becomes a signal of 11 yo, and there is no output to e.

Next, when it is raining, the capacity of C1 increases and the output pulse width from the second multi-vibrator 2 changes to, for example, 2.0 m, SeC, then the pulse from the first vibrator 3 increases. When the clock expires, the clock acts,
The pulses at LK are compared, in this case J is rIJX
K becomes a signal of 10 (zero), and e output oscillates.

Next, when the rain stops, the capacity of C1 decreases again to the original capacity, and the output pulse width from the second multivibrator 2 decreases to 1.
．． When the voltage reaches 0 to 7LSeC and the pulse from the first vibrator 3 is cut off, J becomes a no (zero) signal, K becomes an rIJ signal, and the output of e disappears.

The operation of the above flip-flop is shown in Table 1.

However, Q, Q (clock), J9 Kte
indicates each part in Fig. 2, and the signal detection point to determine whether it is raining is when the pulse d in Fig. 3 is cut off, that is, when the clock turns downward at the position indicated by the arrow in the same figure. .

At that time, the signal of J is determined by the pulses from Q and Q of the second vibrator 2, and the signal of J is emitted to e.

As described above, according to the device of the present invention, it is only necessary to install the capacitor C1 at a location where rain ice can be captured (outdoors, etc.), and it is possible to accurately detect the beginning and end of rain. It is possible to prevent detection from not being possible until a certain amount of rainwater remains, or from oscillating an erroneous signal until there is no remaining rainwater even after the rain has stopped, as in the past.

Furthermore, by adjusting the input pulse width to the clock of the flip-flop 4, it is possible to oscillate the detection output only when the amount of rainfall exceeds a predetermined amount.

In addition, although the embodiment of the present invention uses a CR oscillator, it is also possible to use an LC oscillator, a capacitor bridge, and an L-C oscillator.
Of course, the present invention can also be implemented in a resonant circuit or the like.

This rain detection device can be used, for example, to automatically open and close a skylight in a greenhouse or the like.

In other words, when the signal at e in Fig. 2 is '0 (zero) when it is not raining, the switch of the skylight opening/closing drive device is set to rONJ on the side where the skylight opens. , and the signal at e when it is raining is r1
When the skylight is closed, the switch of the skylight opening/closing drive device is set to 'ONJ' on the side where the skylight closes.

If the rain detection device of the present invention is implemented in a greenhouse in this way,
When it starts to rain, the skylight closes to prevent rain from entering the greenhouse, and when it stops raining, the skylight opens to ventilate the greenhouse. By connecting it to a device that controls the operation of side windows or ventilation fans, the inside of the greenhouse can be maintained in the best condition.

[Brief explanation of drawings]

Figures 1a and b are schematic diagrams showing the structure of a capacitor, Figure 2 is a circuit diagram of a rain detection device showing an embodiment of the present invention, and Figure 3 is a schematic diagram showing the structure of a capacitor.
This figure is a graph showing the pulse output at a predetermined location in FIG. 2, and FIG. 4 is a cross-sectional perspective view showing one embodiment of the rain detection capacitor C1. 1... Trigger generator, 2, 3... Monostable multivibrator, C1... Capacitor for rain detection, C2... Capacitor with constant capacity,
R1, R2...Resistor, 4...Flip-flop circuit section, 5...Base, 6...
・Metal cylindrical body, 7...Metal rod body.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A rain detection device having a capacitor formed so that rainwater can pass between the two electrode plates, the capacitor being formed so that the two electrodes are not electrically connected by the passing rainwater, and a trigger generator; A first multivibrator that receives a trigger pulse and oscillates a pulse of a fixed time; and a second multivibrator that simultaneously receives the trigger pulse and oscillates a pulse of a different width for each time constant according to a change in the capacitance of the capacitor. It consists of a multivibrator and a detection circuit having a flip-flop circuit that compares the pulse widths from both multivibrators and releases or stops a predetermined detection signal, and the final output is adjusted according to the change in capacitor capacity due to the passage of rainwater. A rainfall detection device characterized by controlling the generation of a detection signal. 2. Claim 1 of the above-mentioned registered claim, wherein the detection circuit is configured to generate a detection signal when the amount of rainfall exceeds a predetermined amount.
Rainfall detection device as described in section. 3. The rain detection device according to claim 1, wherein the multivibrator is a monostable multivibrator. 4. The rainfall detection device according to claim 1, wherein one of the capacitor plates is a metal cylinder through which rainwater can pass, and the other is a metal rod fixed in the axial direction of the cylinder.