JPS6142227B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wind vane that electrically detects the direction of the wind.

The main object of the present invention is to realize a wind vane that has no moving parts, has a simple structure, and can also obtain a wind speed signal if necessary.

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, in which A is a front view and B is a sectional view taken along the line B-B in FIG.

In the figure, 1 is a base, 2 is a pressure-receiving column with a circular cross section attached to this base 1, and 3 is an upper plate attached to the top of the pressure-receiving column 2, which serves as a rectifying plate and prevents the effects of rain and snow accumulation. It acts as an umbrella to remove the debris.

The pressure-receiving column 2 is composed of a thin-walled cylinder,
A common electrode 20 is formed on its inner surface. A gap 21 is provided inside this cylindrical pressure receiving column 2.
A cylinder 4 made of an insulating material is arranged concentrically with the cylinders 4a and 4b separated from each other. On the surface of the cylinder 4, four electrodes 41 to 44 having the same area are formed at regular intervals in the circumferential direction, and these electrodes are installed so as to be located in the north, south, east, and west directions.

FIG. 2 is an electrical connection diagram including the common electrode 20 and electrodes 41-44. Here, the electrodes 41 and 42, which are placed facing east and west, form an equivalent circuit that is placed on both sides of the common electrode 20, as shown in the figure, and the capacitance formed by the gap between each electrode.
C ₁ and C ₂ are connected so that they change differentially with respect to the displacement of the pressure receiving cylinder 2. In addition, the electrodes 43 and 44 installed facing north and south are similarly arranged so that the common electrode 20 is sandwiched between the electrodes so that the inter-electrode capacitances C ₃ and C ₄ vary differentially with respect to the displacement of the pressure-receiving cylinder 2. It is connected. OS1 to OS4 all represent AC signal sources, and although each is shown individually here, in reality, for example, a circuit that supplies a signal from one AC oscillator via a transformer is used. D ₁ to _{D 8} are all diodes and constitute diode bridge circuits B ₁ and B ₂ ,
Signals e ₁ and e ₂ corresponding to the interelectrode capacitances C ₃ and C ₄ and the difference between C ₁ and C ₂ are obtained from the resistors R ₁ and R ₂ , respectively.

CK ₁ and CK ₂ are square root calculation circuits that input the obtained signals e ₁ and e ₂ to resistors R ₁ and R ₂ , respectively, and perform square root calculation after obtaining _the average value. An arithmetic circuit that receives signals from the arithmetic circuits CK ₁ , CK ₂ , and these arithmetic circuits CK ₁ , CK ₂ , CK ₀ may use one microcomputer including an A/D converter. . CU is a switch
This is a counter that counts the frequency signal applied via SW and amplifier _A1 .

The operation of the device configured in this way is shown in Figure 1B.
This will be explained with reference to.

First, in a calm state, the pressure receiving column 2 is in a neutral position, and the common electrode 20 and each electrode 41 to 4 are connected to each other.
It is assumed that the gap 20 between the four positions is the same at any position. In this state, the common electrode 2
The interelectrode capacitance Co between 0 and each of the electrodes 41 to 44 can be expressed by equation (1).

Co=εo・S/d (1) where d: distance of gap 20 S: area of each electrode 41 to 44 εo: relative permittivity Now, the wind in the direction shown by the arrow Fo in Figure 1B (north-northeast When a wind) comes, the pressure receiving column 2 receives a force from this wind and changes from its neutral position as shown by the broken line, and the inter-electrode gap between the electrodes 41, 44 and the common electrode 40 narrows. The interelectrode gap between 42, 43 and the common electrode 40 widens.

Here, if the force acting on the pressure receiving column 2 due to the wind speed (wind speed) V is decomposed into the east-west direction F _EW and the north-south direction F _NS , both F _EW and F _NS are proportional to V ² , and these The relationship with the wind direction (here expressed as an angle θ with respect to the north-south direction) can be expressed by equation (2).

Further, assuming that the inter-electrode gap distance changes by Δ±d, the amount of change ΔC in the capacitance between the two sets of electrodes arranged east-west and north-south can be expressed by equation (3).

ΔC=-Co・Δd/d (3) In Figure 2, the resistor R ₁ has a signal corresponding to the difference ΔC _NS between the interelectrode capacitances C ₃ and C ₄ as shown in equation (3).
e ₁ occurs, and the resistance R ₂ has interelectrode capacitances C ₁ and C ₂
A signal e ₂ corresponding to the difference ΔC _EW is generated, and the relationship between these and F _NS and F _EW can be expressed by equations (4) and (5).

√ ₁ ∝√ _NS ∝√ _NS (4) √ ₂ ∝√ _EW ∝√ _EW (5) Arithmetic circuits CK ₁ and CK ₂ input the voltages e ₁ and e ₂ generated in each resistor R ₁ and R ₂ , and By calculating the square root of, equation (6) and (7)
Obtain the signals E _NS and E _EW expressed by the equations.

E _NS ∝√ ₁ (6) E _EW ∝√ ₂ (7) The arithmetic circuit CKo is the signal E _N shown by equations (6) and (7).
By inputting _S and _FEW and performing the calculation shown in equation (8), the wind direction θ can be determined.

θ=tan ⁻¹ ·E _EW /E _NS (8) Note that the direction of the wind, for example, the north-northeast and south-southwest winds can be determined based on the polarity of the outputs e ₁ and e ₂ .

On the other hand, the wind in the direction of the arrow Fo at the pressure receiving column 2 is
After hitting these, a Karman vortex is generated, and the pressure receiving column 2 is vibrated and displaced at a frequency corresponding to the Karman vortex. What is the generation frequency f and wind speed V of the Karman vortex?
There is a relationship shown in equation (9).

f=K・V (9) However, K: Constant In Figure 2, the counter CU receives a frequency signal via the switch SW and amplifier _A1 , which are connected to either contact a or contact b, depending on the wind direction. f
is counted to know the wind speed V.

According to the device configured in this way, there is no movable part, and each electrode serving as a detection part is provided inside the cylindrical pressure receiving column, so that it does not come into contact with the outside air.
Therefore, a wind vane with a simple structure and long life can be realized. Furthermore, a wind vane that can also measure wind speed as needed can be realized.

In addition, although the above-mentioned example was explained assuming the case of measuring the wind direction, it may be installed in seawater to measure the tidal current. Moreover, although four electrodes installed in north, south, east, and west are opposed to a common electrode here, the number of electrodes may be any other number.
In this case, the diameter of the internal cylinder 4, the gap distance, the electrode area, the length of the pressure-receiving column, etc. shall be determined in consideration of the measurement range, etc. Also, it is assumed that an arithmetic expression other than equation (8) is used.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, in which A is a front view, B is a sectional view taken along line B-B in FIG. A, and FIG. 2 is an electrical connection diagram. 1... Base, 2... Pressure receiving column, 3... Current plate, 2
0...Common electrode, 4...Cylinder, 41-44...Electrode, _CK1 , _CK2 , CKo...Arithmetic circuit.

Claims (1)

[Claims] 1. A pressure-receiving column composed of a thin-walled cylinder and having a common electrode provided inside the pressure-receiving column, and at least four or more electrodes disposed inside the pressure-receiving column with a gap in between and equally spaced in the circumferential direction. a cylinder provided with the above-mentioned 4
A wind vane comprising a calculation circuit that detects each capacitance formed between one or more electrodes and a common electrode and calculates a wind direction by calculating signals related to each of these capacitances. 2. The wind vane according to claim 1, which is capable of measuring wind speed by detecting the frequency of change in capacitance.