JPH1198868A - Electrostatic power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to realize a portable power supply, by defining a gap as factor determining capacitance, supplying electric charges at first voltage when the capacitance of a variable capacitance capacitor is increased by external force, and accumulating part of accumulated charges at second voltage higher than the first voltage when the capacitance is reduced. SOLUTION: Electrode 81, 82 with their surface covered with insulator 86 are supported on an elastic body 83 with a gap of 100 μm or below maintained in-between. The electrodes 81, 82 are connected with terminals 84, 85, and the capacitance of a capacitor 10 is varied by moving external force 90 toward the electrodes 81, 82 or moving external force 91 away from the electrodes 81, 82 to take energy out of the terminals 84, 85. If the voltage V1 (V2 >V1 ) of a voltage source is applied to the capacitor 10 when the capacitance of the capacitor 10 is C0 +ΔC, the maximum value, the electric charge Q1 =(C0 +ΔC)V1 . If the capacitance of the capacitor 10 is reduced to C0 due to external force when the electric charger Q1 is constant, the voltage of the voltage source is increased to V2 . If the capacitance of the capacitor 10 is reduced to C=(C0 -ΔC), the accumulated electric charge Q1 -Q2 is sent to the voltage source on the output side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic power generator which can be used as a power source for small autonomous machines used in various fields such as medical welfare equipment, micro robots, precision machines, automobile machine parts, outdoor activity equipment and the like. It is about.

[0002]

2. Description of the Related Art As a portable power source in each autonomous device as described above, a generator using a battery or a heat engine has been conventionally used. However, except for solar cells, there is a limit to the energy source that can be supplied by any of the power sources, and it is necessary to supply energy from the outside by some artificial means. For this reason, it was impossible to exhibit the function autonomously for a long time.

In general, the performance of an electrostatic generator is much lower than that of a magnetic generator. Since the electrostatic generator is used only as a high-voltage generator, it is being sought to increase its size. Therefore, in an electrostatic generator,
There was no idea to micro-generate the power generation mechanism in order to increase the power generation energy density or to reduce the minimum power required for power generation to expand the range of available primary energy.

[0004]

The state of the art of portable power supplies, including the portable power supplies described above, is as follows. (1) There are few methods of generating power using poor quality primary energy, which has a large amount of entropy existing in a large amount in nature. (2) As a portable generator that obtains primary energy from the natural environment, there is a type that uses wind power or hydraulic power, but there are limitations on the environment in which it can be used. (3) As a portable power source, a device using a chemical battery or a heat engine is mainly used, but these cannot be supplied without recharging power or refueling for a long time. (4) In general, the only application is that electrostatic power generation is used to obtain a high voltage. For other uses,
Since the power generation method using a magnetic field has much higher output density, the power generation method using a magnetic field is exclusively used, and the electrostatic power generation method is not practically used. (5) An internal combustion engine type portable generator or the like generates noise due to power generation because a driving force for power generation is obtained by the internal combustion engine. (6) Since the conventional power generating mechanism is difficult to be reduced in size except for the battery, there is a great restriction on the incorporation into the equipment to be used. (7) There is no small high-voltage generator.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, in which the capacitance per unit volume is greatly increased by miniaturizing a variable capacitor, and the capacitance is varied by a minute external force. An object of the present invention is to provide a portable electrostatic power generation device suitable for various uses.

[0006]

Means for Solving the Problems An electrostatic power generator according to the present invention for achieving the above object has the following arrangement. That is, the gap between the elements contributing to the determination of the capacitance is 10
A variable capacitor having a capacitance of 0 μm or less, the capacitance of which is changed by an external force; and supplying a charge to the variable capacitor by a first voltage when the capacitance of the variable capacitor is increased by the external force. When the capacitance of the variable capacitor is reduced by the supply means and the external force, a part of the electric charge stored in the variable capacitor is stored at a second voltage higher than the first voltage. Storage means.

[0007]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Before the description of the embodiment, the basic configuration and operation principle of the electrostatic power generation device according to the present embodiment will be described.

[Basic Operation Principle] FIG. 1 is a diagram showing the basic configuration of the electrostatic power generating device according to the present embodiment. FIG.
FIG. 3 and FIG. 3 are diagrams for explaining the basic operation principle of the electrostatic power generating device according to the present embodiment.

FIG. 1 shows a typical example of a variable capacity power generation circuit. In FIG. 1, reference numeral 10 denotes a variable-capacitance type capacitor whose capacitance changes by mechanical force, 53 and 54 denote diodes, and 51 and 52 denote voltage sources. In order to make the operation easy to understand, the voltage sources 51 and 52 are both constant voltage sources, the voltage of the input side voltage source 51 is V1, the voltage of the output side voltage source 52 is V2, and V2> V1. . Also, the forward voltage drop of the diode is ignored.

Here, it is assumed that the capacitance of the variable capacitance type capacitor 10 changes as shown in FIG. 2 due to an external force. Hereinafter, the energy extracted from the variable capacitor 10 will be described with reference to FIGS. 2 and 3.

(1) First, at the time t = a in FIG. 2, the capacitance of the variable capacitor 10 (hereinafter simply referred to as the capacitor 10) has the maximum value C0 + ΔC. At this point, electric charges are supplied from the voltage source 11 to the capacitor 10. This state corresponds to the point a in FIG. 3, and the charge Q1 at that time is Q1 = (C0 + ΔC)
V1.

(2) Next, in a state where the charge Q1 is constant, FIG.
Until the time t becomes b, the capacitor 1
When the capacitance of 0 changes, the capacitor 1
The voltage of 0 changes. When the capacitance decreases to C0,
Meanwhile, the voltage of the capacitor 10 rises to V2, and FIG.
To point b.

(3) At this time (when the voltage of the capacitor 10 reaches the voltage V2 of the voltage source 52), the diode 54
Is conducted, and the voltage of the capacitor 10 is maintained at V2. During this time, when the capacitance of the capacitor 10 further decreases until C = C0−ΔC due to an external force, the capacitor 10
(Q1-Q2) accumulated on the output side of the voltage source 5
2 and reaches point c in FIG.

(4) When the capacitance of the capacitor 10 is increased to C0 with the constant charge Q2 from the point c (FIG. 2)
At time d), the voltage of the capacitor 10 decreases to V1,
The point d in FIG. 3 is reached. From this point to point a, when the capacitance of the capacitor 10 is increased to C0 + ΔC by an external force at a constant voltage V1, power is supplied from the voltage source 51 on the input side, and the charge increases to Q1. And complete one cycle.

Here, the net output energy E per cycle corresponds to the area surrounded by the sides ab, bc, cd and da. Therefore, E = (Q1-Q2) V2- (Q1-Q2) V1 = (Q1-Q2) (V2-V1) = {(C0 + ΔC) V1- (C0-ΔC) V2} (V2-V1) = ＶΔC (V2 ^ 2-V1 ^ 2) -C0 (V2-V1) ^ 2} (1) If there are f repetitions per second, the output power P is P = Ef = f ＝ ΔC (V2 ^ 2-V1 ^ 2) -C0 (V2-V1) ^ 2｝ (2) In the present specification, X ^ Y represents X to the power of Y.

In this generator, it is necessary to supply electric charges from the voltage source 51 on the input side to the capacitor 10. For this reason, at the early stage of operation, electric energy must be supplied using a battery or the like. However, once power generation is performed and the stored energy reaches a certain level, for example, when predetermined energy is stored in the voltage source 52, power can be branched therefrom to supply electric charge to the capacitor 10. . Therefore, the life of the power source on the input side does not matter.

Next, an example of the basic structure of a variable capacitor that can be used as the capacitor 10 will be described. There are three basic principles of the method of changing the capacitance: changing the distance between the electrodes, changing the electrode plate area, and changing the dielectric constant between the electrodes. Hereinafter, these methods will be described using a parallel plate type capacitor having a simple structure.

FIG. 4 is a diagram showing an example in which the capacitance is made variable by changing the distance between the electrode plates. In the structure shown in FIG. 4, the capacitance of the capacitor can be expressed by equation (3).

C (x) = ε0 · εrg · W · L / x [F] (3) where C (x) is the capacitance [F] of the capacitor 10 and ε
0 is the dielectric constant in vacuum [F / m], εrg is the relative dielectric constant of the substance 13 filling the space between the electrodes (almost 1 in the case of air), and L is the length of the electrode [m]. , W is the electrode width [m], and x is the distance between the electrodes [m].

As can be seen from equation (3), the capacitor 1
The distance x between the electrode 11 and the electrode 12 forming 0 is shortened by some external force 20a, so that the capacitor 10
Can be increased (see FIG. 4A). The capacitance x of the capacitor 10 can be reduced by increasing the distance x between the electrode 11 and the electrode 12 forming the capacitor 10 with some external force 21a (see FIG. 4B).

In FIG. 4, terminals 14 and 15 are terminals for taking out electric charges. Energy can be extracted by connecting the capacitor 10 using the terminals 14 and 15 as shown in the electronic circuit of FIG. 1 and applying a fluctuating force that changes the distance between the electrode plates as described above.

FIG. 5 is a diagram showing an example in which the capacitance is made variable by changing the electrode plate area. In the method shown in FIG. 5, when the external force 20b is applied, as shown in FIG. 5A, the electrodes 11 and 12 are installed so as to face each other and completely overlap each other. In this state, the capacitance has a maximum value. When the external force 21b is applied to the electrode 12, the length (Lx) of the overlapping portion between the electrode 11 and the electrode 12 decreases as shown in FIG. The capacity decreases.

C (x) = ε0 · εrg · W · (L−x) / D [F] (4) Here, x is a shift in a lateral direction from a state in which the electrodes 11 and 12 are completely overlapped [ m] and D are the distance [m] between the opposed electrodes. Other symbols are the same as those shown in FIG.

The capacitor 10 is connected using the terminals 14 and 15 as shown in the electronic circuit of FIG.
When an external force corresponding to 1b is applied, energy can be extracted from the capacitor 10.

FIG. 6 is a diagram showing an example in which the capacitance is made variable by changing the dielectric constant between the electrode plates. In FIG. 6A, a pair of electrodes 11 and 12 are placed facing each other,
In addition, the dielectric 16 is completely inserted into the space 13 formed by the electrode by the external force 20c. At this time, the capacitance becomes the maximum value. In FIG. 6B, the dielectric 16 is pulled out of the space 13 between the electrodes by the external force 21c, and the insertion amount x is reduced. In this case, as can be seen from the following equation (5), the capacitance of the capacitor 10 becomes small.

C (x) = ε0 · εrg · w · L / D + {ε0εrg (εrs−εrg) wd / D (2gεrs + dεrg)} · x (5) where εrs fills the space 13 between the electrodes. Εrs is the relative permittivity of the movable dielectric 16, w is the narrower of the widths of the electrodes 11 and 12 or the width of the movable dielectric 16. The width [m] (in this example, the width w of the movable dielectric 16), 2g is the length [m] of the gap between the electrodes 11, 12 and the movable dielectric 16, and d is the thickness [m] of the movable dielectric 16. ], L is the length of the electrode [m], D (= 2 g)
+ D) is the distance [m] between the electrodes, and x is the insertion amount [m] of the movable dielectric 16 between the electrodes.

The capacitors 10 are connected using the terminals 14 and 15 as shown in the electronic circuit of FIG.
If a fluctuating force corresponding to c is given, energy can be extracted from the capacitor 10.

As can be seen from the above equation (2), V1,
If V2 is defined, the output energy P is the change in capacitance Δ
C determines its size. As described above, ΔC is obtained by changing the gap or the facing area between the electrodes by mechanical displacement, or by changing the dielectric constant of a substance interposed in the gap. Here, the capacitance of the capacitor is approximately expressed by C = εr · ε0 · S / d. (Where C is the capacitance, εr is the relative dielectric constant of the material between the electrodes, and ε0 is the dielectric constant of vacuum (8.854 × 10 ^ -1).
2), d is the gap between the electrodes) Therefore, the capacitance can be changed by changing ε, S, d. in this case,
If the minimum value Cmin of C is about 1/5 of the maximum value Cmax of C, there is no problem in practical use (that is, ΔC = 0.4
Cmax).

First, as shown in FIG.
Is changed. The smaller the value of d, the better the Cmax can be taken, so it is convenient. However, the minimum distance is to avoid friction when the voltage generated between the electrodes and the relative position of the electrodes change. And the thickness of the insulating film. The voltage V2 on the secondary side is practically considered to be in the range of 1 to 100 [V] unless an extremely large voltage is considered. Therefore, the minimum distance d between the electrode plates is about 0.1 to 10 μm in the film thickness used in a normal film capacitor, and the maximum is 20 μm.
The size is about μm (the optimum film thickness depends on the material and applied voltage).

On the other hand, the minimum capacitance is 1 which is the maximum value.
/ 5 or less (the distance d between the electrodes is therefore more than 5 times). Therefore, if the distance between the electrodes is at most 100 μm, a sufficient distance between the electrodes can be obtained. It is clear that if the distance between the electrodes can be reduced, the number of electrodes that can be installed per unit volume will increase, so it is meaningless to increase the distance between the electrodes further in making a practical machine.

As shown in FIG. 5, when the area (S) of the opposed electrodes is changed, the distance between the electrodes is constant, but the distance between the electrodes is 0.1 μm due to friction or the like.
To several tens of μm, preferably at most 100 μm.

Further, as shown in FIG. 6, in the case of changing the dielectric constant (ε) between the electrodes, a distance between the electrodes is several tens μm at the minimum and several tens μm at the maximum to insert a dielectric between the electrodes. mm. However, sufficient performance cannot be obtained unless the gap between the dielectric and the electrode is 100 μm or less, preferably several tens μm or less. Further, as shown in FIG. 6, in the case of the method of changing the dielectric constant (ε) between the electrodes, the capacitance becomes minimum when the low dielectric material is located between the electrodes. It is sufficient to take a value similar to the maximum inter-electrode distance in the method of changing the inter-electrode distance, so that the maximum value is 100 μm or less.

As described above, for example, when the distance between the electrodes is changed (the method of FIG. 4), the distance between a pair of electrodes (hereinafter, referred to as an electrode pair) is 100 μm at the maximum. Therefore, the displacement per electrode pair is at most about 100 μm,
When an external force having a large displacement acts, it is necessary to stack these. Further, in the case where the external force is a vibration having a small amplitude or the like, it is necessary to arrange a large number of electrodes in a separated form so that the displacement between the electrode pairs does not interfere with each other. In the former case, the electrodes may be simply connected in parallel as shown in FIG. 19A if the operation is performed so that the local maximum and minimum of the stacked interelectrode capacitances coincide with each other.

In the latter case, that is, when there are many directions of vibration, a power generation unit having no direction dependency of external force can be constituted by arranging the electrode pairs in a plurality of directions. is there. In each of the methods described with reference to FIGS.
V or more), all may be connected in parallel. However,
As described above, when there are a plurality of vibration directions or when the cycles and phases of expansion and contraction of the electrode gap are not synchronized, the electrodes of the diode 53 and the diode 54 shown in FIG. It is necessary to connect in parallel at the cathode. That is, the connection is made as shown in FIG.

Hereinafter, embodiments of the variable capacitor according to the present invention will be described with reference to the first to ninth embodiments. In the first to fourth embodiments, an example in which the capacitance is made variable by changing the distance between the electrode plates shown in FIG. 4 will be described. In the fifth and sixth embodiments, examples in which the capacitance is variable by changing the electrode plate area will be described. Further, in the seventh to eighth embodiments, examples in which the capacitance is made variable by changing the dielectric constant between the electrode plates will be described.

[First Embodiment] FIG. 7 is a diagram for explaining the configuration of a variable capacitor according to the first embodiment.
In FIG. 7A, the electrode 81 and the electrode 82 are supported by an elastic body 83 to maintain an appropriate distance between the electrodes. Further, the surfaces of the electrodes 81 and 82 are covered with an insulator 86 to prevent leakage of electric charges due to an emergency contact. In addition,
If there is no possibility of contact between the electrodes 81 and 82, the insulator 86
Can be omitted.

The electrodes 81 and 82 are connected to terminals 84 and 85. The terminals 84 and 85 are connected as shown in the electronic circuit of FIG. 1, and the electrodes 81 and 82 are brought closer by an external force 90 as shown in FIG. 7A, or as shown in FIG. By separating the electrodes 81 and 82 by the external force 91, the capacitance of the capacitor 10 fluctuates.
As a result, energy can be extracted from the terminals 84 and 85 as described above.

When the space 87 between the electrodes 81 and 82 is filled with a substance having a large relative permittivity, the change in capacitance becomes larger than when the electrodes 81 and 82 are filled with air even if the displacement of the electrodes 81 and 82 is the same.

Next, the dimensions of the electrodes in the first embodiment will be examined.

The total electrode area (one pole) defines the maximum value of the capacitance.
[A], if the repetition frequency of expansion and contraction of the electrode gap is F [Hz], and the voltage of the charge supply source is V1 [V], C = IL / (F · V1) = εr · ε0 · S / dmin S = IL · dmin / (F · V1 · εr · ε0) As an example, IL = 1 [mA], F = 10 [Hz], V
1 = 0.1 [V], εr = 10, ε0 = 8.854 × 0 ^
If −12 [F / m] and dmin = 0.1 [μm], then S = 1.1 [m ^ 2]. The area of each layer is 10 ^ -4 [m ^ 2] (10 mm
Angle), the total number of laminations is about 11000, but if the electrode plate gap dmax at the time of expansion is 1 [μm] and the thickness of the support is considered to be about the same, the total height is 11 [mm]. ]
Becomes

As described above, the distance between the electrodes is 100
It is preferable that the distance be set to μm or less, but the limitation of the distance between the electrodes can be achieved by providing a mechanical limiter in a holding portion (or housing) of the entire mechanism. The stacked electrodes are connected in parallel in the form described in FIG. 19A or 19B.

In FIG. 7, the elastic body 83 may be a balloon-shaped one or a bellows-shaped one. Further, if there is no problem even if the substance filled in the space 87 leaks like air, it is not always necessary to seal the substance.

[Second Embodiment] FIGS. 8A and 8B are diagrams illustrating the configuration of a variable capacitor according to a second embodiment. 8A and 8B, elastic thin films 101, 102, 103, and 1 having a sine-wave-like shape and high insulation properties.
04, conductive films 121, 122, 12
3, 124, 125 and 126 (hereinafter referred to as electrodes) are attached. Further, the electrodes 121 to 126
Insulating films 131, 132, 133, 134, 13
5 and 136 are applied. The adjacent insulating films 131 and 132, 133 and 134, and 135 and 136 are joined to each other at the vertices of a sinusoidal shape.

The electrode 121 is connected to the terminal 141 and the electrode 1
The electrodes 22 and 123 are electrically connected to the terminal 142, the electrodes 124 and 125 are electrically connected to the terminal 143, and the electrode 126 is electrically connected to the terminal 144, respectively. Terminal 141 and terminal 143 are connected to the positive electrode (or negative electrode) of the electronic circuit of FIG.
The terminal 42 and the terminal 144 are connected to the negative electrode (or positive electrode) of the electronic circuit of FIG. The elastic thin films 101 to 104 provided with electrodes and insulating films are sandwiched between external force transmission plates 151 and 152. However, the elastic thin films 101 to 104
Can slide along the surfaces of the external force transmission plates 151 and 152 in a parallel direction, and can assume a state as shown in FIGS. 8A and 8B.

In FIG. 8A, when there is no external force 162 or the external force 162 is acting outward, the elastic thin films 101 to 104 have the maximum sine wave amplitude due to their own elastic force (of course, the external force 161 is applied. May be). Accordingly, the capacitance between the opposing electrodes 121 and 122, the electrodes 123 and 124, and the electrodes 125 and 126 has a minimum value.

FIG. 8B shows a state in which the external force 162 is acting inward, and the external force 162 overcomes the elastic repulsion caused by the deformation of the elastic thin film groups 101 to 104, and the amplitude of the sine wave becomes small. I have. Thus, the opposing electrodes 121 and 122, 123 and 124, and 125 and 12
6, the distance between them has become shorter, and the capacitance between them has a large value.

By repeating the state shown in FIG. 8A and the state shown in FIG. 8B, the capacitance changes, and the terminals 141 and 143 are changed.
And energy can be extracted from between 142 and 144.

When the electrodes are attached to only one surface on the same side of the elastic thin film in a similar structure, the insulating film can be omitted. It is also apparent that the same function can be achieved by using an elastic metal film as an electrode without using an elastic thin film and coating the electrode with an insulating film.

Further, when the electrode space is filled with a substance having a large relative dielectric constant, the change in capacitance becomes larger than when the space is filled with air. Further, in the second embodiment, four sets of the laminated sheet composed of the elastic thin film, the conductive film, and the insulating film are used. However, it is needless to say that the number of the laminated sheets used is not limited to this.

The integration and the dimensions of the electrode pairs according to the second embodiment are the same as those of the first embodiment, and the description is omitted. Further, it is preferable that the distance between the electrodes is 100 μm or less at the maximum part (wave-shaped apex part) at the time of expansion. Limiting the distance between the electrodes can be achieved by providing a mechanical limiter on the holding portion (or housing) of the entire mechanism. When a plurality of variable capacitance capacitors shown in FIGS. 8A and 8B are connected, they may be connected in parallel in the form shown in FIG. 19A or 19B.

[Third Embodiment] FIGS. 9A and 9B are diagrams illustrating the configuration of a variable capacitor according to a third embodiment. In the drawing, electrodes 211 and 212 are attached to both surfaces of an insulating polymer elastic film 210 having a coil spring-like shape, and the surface of the electrode 212 is
Coat with 13. Electrodes 211 and 212 are connected to terminals 215 and 216, respectively. Further, one end 217 of the coil spring-shaped polymer elastic film 210 is
0 and the other end 218 is joined to the mass 221.

In FIG. 9A, the external force 230 acts downward on the mass 221, and the pitch between the coiled polymer elastic film 210 and the electrodes 211 and 212 and the insulating film 213 joined thereto is elongated. Have been. As a result, the distance between the electrodes 211 and 212 increases, and the capacitance between the terminals 215 and 216 decreases.

On the other hand, in FIG. 9B, an external force 231 acts on the mass 221 in the upward direction, and the polymer elastic film 210 having a coil shape and the electrodes 211 and 212 bonded thereto are formed.
In addition, the pitch interval between the insulating films 213 is reduced. As a result, the distance between the electrodes 211 and 212 is reduced, and the capacitance between the terminals 215 and 216 is increased.

9A and 9B are connected to the electronic circuit of FIG. 1 using terminals 215 and 216, and an appropriate external force 230 separates the electrodes 211 and 212 as shown in FIG. As shown in FIG. 9B, when the capacitance between the terminals 215 and 216 is changed by bringing the electrodes 211 and 212 closer to each other with an appropriate external force 231, energy can be extracted from the terminals 215 and 216.

The dimensions and integration of the electrode pairs according to the fourth embodiment are the same as in the first embodiment.
However, the interval per coil is 100μ at maximum expansion.
m or less. Such a limitation on the distance between the electrodes can be achieved by providing a mechanical limiter in a holding portion (or housing) of the entire mechanism.

[Fourth Embodiment] FIG. 10 is a view for explaining the arrangement of a variable capacitor according to a fourth embodiment. In FIG. 10, a polymer elastic film 31 having a spiral shape is shown.
Electrodes 311 and 312 are attached to the surfaces on both sides of 0, and the respective surfaces are further coated with insulating films 313 and 314. Electrodes 311 and 312 are connected to terminals 315 and 31 respectively.
6. Further, one end 317 of the spiral polymer elastic film is fixed to the substrate 322, and the other end 318 is joined to the mass 321. The mass 321 is
It is rotatable about its axis 321a.

As shown in FIG. 10A, the mass 3
When an external force 330 acts clockwise on 21, the spiral shape of the polymer elastic film 310 and the electrodes 311 and 312 and the insulating films 313 and 314 joined thereto expands. As a result, the distance between the electrodes 311 and 312 (the distance between the electrodes) increases, and the overall capacitance decreases.

On the other hand, as shown in FIG.
When the external force 331 acts counterclockwise on the mass 321,
Polymer elastic membrane 310 and electrodes 311 and 3 bonded thereto
12 and the insulating films 313 and 314 are deformed in a spiraling direction. As a result, the distance between the electrodes is shortened, and the overall capacitance is increased.

The variable capacitance type capacitor shown in FIG. 10 is connected using terminals 315 and 316 as shown in the electronic circuit of FIG. Then, the opposing electrodes 311 and 312 are separated by an external force 330 as shown in FIG. 10A, or the opposing electrodes 31 as shown in FIG.
By bringing 1 and 312 closer to the external force 331, the capacitance of the capacitor changes, and the terminals 315 and 316
Energy can be extracted from

In this embodiment, a change in the electrode plate gap occurs between the inner electrode 312 and the counter electrode that has advanced one turn toward the center. For this reason, since the elastic body 310 does not contribute to the change in capacitance, it is desirable that the influence can be neglected at least when the elastic body 310 is expanded.

One example of the dimensions of the electrode plate according to the fourth embodiment is as follows. The thickness per turn at the time of contraction (FIG. 10B) is the sum of the electrode gap dmin and the thickness ds of the spiral spring member. Spring material length L and number of turns n
L = 2π (dmin + ds) (1 + 2 + 3 +... + N) = π (dmin + ds) (n + 1) · n In order to obtain the same capacity as that of the first embodiment at the time of contraction, the width of the spiral spring is W, S = W · L = W · π (dmin + ds) (n + 1) · n = 1.1 [m ^ 2] W = 20 [mm], dmin = 0.1 [μm], ds = 1
Assuming 0 [μm], (n + 1) · n = 1.129 / (6.346 × 10 ^ −
7) From this, n = 666 is obtained, and the radius at the time of contraction is Assuming that the distance between the electrodes at the time of expansion (FIG. 10A) is dmax = 1 [μm] as in the first embodiment, the radius after expansion is Becomes

[Fifth Embodiment] FIGS. 11A and 11B are diagrams illustrating the configuration of a variable capacitor according to a fifth embodiment. 11A and 11B, the electrodes 411 and 412 are shaped like comb teeth and have a width in the depth direction. The electrode 411 is partially connected to the leaf springs 413 and 414. Also, the ends 421 and 422 of the leaf springs 413 and 414 on the opposite side to the end connected to the electrode 411 are
It is fixed to the substrate 420 in an insulated state. The electrodes 411 are supported by the plate springs 413 and 414 so as to float in the air. Then, the electrode 411 can be displaced in parallel in the left-right direction in the figure.
On the other hand, the electrode 412 is fixed to the substrate 420 while being insulated from the substrate 20. As a result, the electrodes 411, 41
2 is such that its relative position changes in accordance with external forces 430 and 431. Electrodes 411 and 412 are electrically connected to terminals 415 and 416, respectively.

As shown in FIG. 11A, when an external force 430 acts on the electrode 411 in the leftward direction as shown in FIG. 11A, and the electrode 411 and the electrode 412 approach each other, the capacitor formed by the electrodes 411 and 412 is substantially turned off. The electrode area increases, and the capacitance increases.

On the other hand, as shown in FIG. 11B, an external force 431 acts on the electrode 411 in the right direction as shown in FIG.
If one moves away from electrode 412, electrodes 411 and 4
12, the substantial plate area of the capacitor formed is reduced, and the capacitance is reduced.

Therefore, by connecting the variable capacitance type capacitors shown in FIGS. 11A and 11B using the terminals 415 and 416 as shown in the electronic circuit of FIG. 1 and applying external forces 430 and 431, that is, in FIG. As the electrode 411
11 and 412 are brought closer to the external force 430, and the electrodes 411 and 412 are separated by the external force 431 as shown in FIG.
And 416 can extract energy.

Next, an example of the dimensions of the comb electrode type capacitor according to the fifth embodiment will be described. FIG. 11C shows a dimension of a comb-shaped electrode according to the fifth embodiment. It is assumed that the movable element (electrode 411) is wired so as to be a negative electrode (earth) and the stator (electrode 412) is wired so as to be a positive electrode. In FIG. 11C, the mover is in a stable position, and the movement range around this is ± 4 μm. The thickness t of the electrode in a direction perpendicular to the paper is 5 μm.

First, a region surrounded by a two-dot chain line abcd is set as a unit region, and a change in capacitance in this region is calculated. Note that the electric field is treated as an ideal state, and it is assumed that the electric field is generated only in a portion where the electrode surfaces always face each other in a right angle direction.

The capacitance obtained in abcd is A,
It is the sum of the B, C, D, and E parts. The mover and stator are
The capacitance at each part is CC = CA + CE, CB = C
It has a shape with symmetry such as D.

First, the capacitance C1 when the mover moves farthest from the stator is determined. The capacitance of the part C at that time is Cc1, and the capacitance of the part B at that time is Cb1. The distance between the electrodes of the portion C is dc1 and the distance between the electrodes of the portion B is db1. The electrode width of section C is Wc1, and B
The electrode width of the portion is Wb1.

Cc1 = t × Wc1 × 8.85 × 10 ^ -12 / dc1 = 5 × 10 ^ -6 × 3 × 10 ^ -6 × 8.85 × 10 ^ -12 / (9 × 10 ^ -6 ) = 14.75 * 10 <-18> [F] Cb1 = t * Wb1 * 8.85 * 10 @ -12 / db1 = 5 * 10 @ -6 * 1 * 10 @ -6 * 8.85 * 10 @ -12 / (3 × 10 ^ -6) = 14.75 × 10 ^ -18 [F] Therefore, the total capacitance C1 in the unit area is: C1 = 2Cc1 + 2Cb1 = 59 × 10 ^ -18 [F] Become.

Next, the capacitance C2 when the mover moves to the right when it comes closest to the stator is determined. The capacitance of the portion C at that time is Cc2, and the capacitance of the portion B at that time is Cb2. The electrode width of the part C is Wc2, and the distance between the electrodes of the part B is db2. The electrode width of the portion C is Wc2, and the electrode width of the portion B is Wb2.

Cc2 = t × Wc2 × 8.85 × 10 ^ -12 / dc2 = 5 × 10 ^ -6 × 3 × 10 ^ -6 × 8.85 × 10 ^ -12 / (1 × 10 ^ -6 ) = 132.75 × 10 -18 [F] Cb2 = t × Wb2 × 8.85 × 10 -12 / db2 = 5 × 10 -6 × 9 × 10 -6 × 8.85 × 10 -12 / (3 × 10 ^ -6) = 132.75 × 10 ^ -18 [F] Therefore, the total capacitance C2 in the unit area is C2 = 2Cc2 + 2Cb2 = 531 × 10１０-18 [F] unit The variation of the capacitance in the area is C2-C1 = 472 × 10 ^ -18 [F].

When a large number of such one-unit capacitors are gathered to be about 0.25 [μF], the performance as a variable capacitor can be satisfied. Here, when the required number n of the unit capacitors is obtained, n = 250 × 10 ^ -9 / (472 × 10 ^ -18) = 0.529 × 10 ^ 9 ≒ 0.53G pieces.

Now, it will be estimated how large these capacitors will be. Vibration can be used without waste only after two capacitors of one unit are gathered. Therefore, the actual basic unit requires twice the area surrounded by the two-dot chain line abcd. Therefore, the area A0 is A0 = 2 × 25 × 10１０-6 × 12 × 10 ^ -6 = 6 × 10 ^ -1
0 [m ^ 2].

However, in order to effectively operate them, an area is also required for a spring mechanism for maintaining the mover in a space and a wiring portion. Estimate the degree. That is, an area efficiency of 50
%, The required unit area Au is as follows: Au = AO × 2 = 12 × 10 -10 [m ^ 2] Assuming that the thickness of the silicon substrate is 0.5 [mm], the unit volume Vu occupied by the unit capacitor is as follows: Vu = Au × 5 × 10 −4 = 6 × 10 13 −m 3. Therefore, the volume V necessary for accommodating all the necessary capacitor elements is: V = Vu × n = 6 × 10 13 −0.53 × 10 9 = 3.18 × 10 −4 [m 3] = 318 [cm ^ 3], and thus about 7 cm3.

Here, the thickness of the silicon substrate is set to 0.1 [m
m], the required volume V is V = 63.6 [cm ^ 3]. Therefore, it is about 4 cm3. When a plurality of comb-shaped variable capacitors are connected in parallel, they are connected as shown in FIG. 19 (a) or (b).

[Sixth Embodiment] FIG. 12 is a view for explaining the arrangement of a variable capacitor according to a sixth embodiment. In FIG. 12, four electrodes 5 each having a petal-like shape
10 is joined to the shaft 512. The electrode 511 having the same shape as the electrode 510 is joined to the bearing 513. The electrodes 510 and 511 are installed via a bearing 513 and a shaft 512 so as to face each other in parallel, and are in a state where the relative rotation angle can be changed. The electrode 511 is fixed to the substrate 520, and the bearing 513
Is electrically coupled to the terminal 515 via the Electrode 510 is electrically coupled to terminal 514 via shaft 512. However, the bearing 513 and the shaft 512 are electrically insulated.

In FIG. 12A, the electrode 510 is
The angle is the least overlapped facing 11. As a result, the substantial plate area of the capacitor formed by the electrodes 510 and 511 is minimized, and the electrodes 510 and 5
The capacitance generated during 11 is the smallest.

On the other hand, in FIG. 12B, the angle at which the electrode 510 is opposed to the electrode 511 is the most overlapped. As a result, the substantial plate area of the capacitor formed by the electrodes 510 and 511 is maximized, and
And 511 are in the largest state.

As is clear from FIGS. 12A and 12B, the capacitance of the variable capacitance type capacitor according to the sixth embodiment is obtained by appropriately applying an external force 530 to the electrode 510 and the electrode 511. Can be changed by changing the basic angle. Therefore, by connecting the variable capacitance type capacitor of the sixth embodiment as shown in FIG. 12 by the terminals 514 and 515 as shown in the electronic circuit of FIG. 1, and changing the capacitance to an external force 530, FIG.
As shown in (a) and (b), by changing the capacitance by rotating the electrode 510 to change the degree of overlap between the electrodes 510 and 511, energy can be extracted from the terminals 514 and 515.

The number of divisions of the petal shape of the electrode is not limited to four as shown in this embodiment, but may be any number. However, the greater the number of divisions, the greater the change in capacitance with respect to the rotation angle. Further, as for the relative rotation angle between the electrodes 510 and 511, it is preferable that the change in the area of the overlapping portion of the two electrodes is at least １ ／ or more of the electrode area.

The electrode gap when a pair of electrodes face each other is d
= 0.1 to 10 μm is preferable (the reason will be described later). When the diameter of the electrode pair is increased, the thickness of the electrode is increased in order to prevent the deflection of the electrode due to the rotation, and the volume of the entire power generation unit is increased. Therefore, in order to increase energy, a shape in which a large number of electrode pairs are stacked in the axial direction is desirable. Further, by doing so, it is possible to reduce the distortion of the electrodes due to the Coulomb force generated between the corresponding electrodes.

When the radius of the disk is r = 10 [mm] and the electrode occupancy η is 0.4, the number n of electrode pairs for obtaining the same electrode area as in the first embodiment is obtained. S / (πr ^ 2 · η) = 1.1 / (π × 100 × 10 ^ −5 × 0.4) = 8758 If the pitch of the electrode pair is 10 μm, the total length in the axial direction is L = n × 0 .01 = 87 [mm].

As the displacement, the minimum displacement for changing the capacitance from the maximum to the minimum is the number of electrodes K per electrode (the number of electrodes).
However, even if the displacement is further increased, a change in capacitance can be obtained repeatedly. K may be increased with respect to the electrode gap d within a range that satisfies the relationship of 2πr / K> 20d. If d = 0.
If it is 1 μm, K <30000. If k = 1000, in the case of the sixth embodiment, 2π / 1000 to ∞
It is effective over a wide range of angle changes of [rad].
When a plurality of variable capacitance capacitors as shown in FIG. 12 are connected, the connection is made in the form shown in either (a) or (b) of FIG.

[Seventh Embodiment] FIG. 13 is a view for explaining the arrangement of a variable capacitor according to the seventh embodiment. In FIG. 13, the electrode 60 is placed on the electrode support 620.
1, 602, 603, 604, 605 and 606 are attached. These electrode groups 601 to 606 are connected to terminal 6
41 and is electrically connected. Also, the electrode support 62
1, electrodes 611, 612, 613, 614, 61
5 and 616 are attached. These electrode groups 6
11 to 616 are electrically connected to the terminal 642.
Then, the electrode groups 601 to 606 and the electrode groups 611 to 615
Are opposed to each other, and a capacitor is formed for each pair of electrodes. The mover 630 is inserted into the space 650 of these capacitors. Mover 63
0 is formed by alternately arranging and joining a dielectric material 631 having a high dielectric constant and a non-dielectric material (or a dielectric material having a low dielectric constant) 632 on a straight line. In addition,
The arrangement interval of the dielectric material 632 is equal to the arrangement interval of the electrodes.

In FIG. 13A, the positional relationship between the mover 630 and the capacitor group is such that the external force 630 inserts the dielectric material 631 having a high dielectric constant into the electrode group forming the capacitor. It has become. The non-dielectric material (or a dielectric material having a low dielectric constant) 632 is in a state of being located outside the electrode group forming the capacitor. As a result, the capacitance measured between the terminals 641 and 642 shows the maximum value.

In FIG. 13B, the portion of the dielectric material 631 having a high dielectric constant of the mover 630 is
It is in a state of being drawn out of the electrode group forming the capacitor by the external force 660. As a result, a portion of the non-dielectric material (or a dielectric material having a low dielectric constant) 632 is inserted into the electrode group forming the capacitor. Therefore, the capacitance measured at the terminals 641 and 642 shows the minimum value.

As described above, by appropriately applying the external forces 660 and 661, the capacitance of the variable capacitance type capacitor shown in FIG. 13 can be changed. Therefore, FIG.
Are connected via terminals 641 and 642 as shown in the electronic circuit of FIG.
1 to change the capacitance, that is, the positional relationship between the mover 630 and the electrode group is changed as shown in FIG.
13 or by changing the capacitance between the terminals as shown in FIG.
Energy can be extracted from 41 and 642.

According to the seventh embodiment, since a large number of movable elements and electrodes are arranged so as to be arranged side by side, a large change in capacitance can be obtained by a slight movement of the movable element. Can be.

In this case, the electrode gap between the electrode pairs is also d = 0.
The thickness is preferably about 1 to 10 μm, and the thickness of the interposed mover 630 is also approximately this size. If the electrode has a porous surface as described in a ninth embodiment described below, a gap is formed between the mover and the electrode surface in a range not more than the thickness of the mover so as not to hinder the movement of the mover. There may be.

The width of the entire electrode pair in FIG.
[Mm], and the length (the depth direction in the figure) is L = 10 [m].
m], the dielectric constant of the dielectric portion 631 of the mover is set to be substantially the same as that of the film of the first embodiment, and the electrode occupancy η is set to 0.5 to obtain the same electrode area as that of the first embodiment. When the number n of the electrode pairs is obtained, n = S / (W × L × η) = 1.1 / (10 × 10 -3 × 10 × 10 -3 × 0.5) = 22000 When the thickness is 10 μm, the total height after lamination is H = 22000 × 0.01 = 220 [mm].

The minimum displacement for changing the capacitance from the maximum to the minimum is determined by the pitch P (electrode pitch) of the electrodes formed on the electrode support. Change can be obtained. Since it is considered that P may be reduced to about 10 times the electrode gap, if d = 0.1 μm, P = 1 μm
But it is good. Even if the displacement of the mover is 1 [mm], the decrease in the total counter electrode area is only 10%, so in the case of this embodiment,
This is effective over a wide range of displacement of about 0.001 to 1 [mm].

When a plurality of variable capacitance capacitors shown in FIG. 13 are connected, they are connected in a form as shown in FIG. 19 (a) or (b).

[Eighth Embodiment] FIG. 14 is a view for explaining the arrangement of a variable capacitor according to the eighth embodiment. In FIG. 14, an electrode 7 having four petals is formed.
The electrode 10 and the electrode 711 having the same shape as the electrode 710 are joined to the shaft 713 at an appropriate interval so as to face in parallel with each other to form a capacitor. Shaft 713 and Shaft 71
4 have the same center of rotation 718, and are paired around each other. The mover 712 having the same shape as the electrode 710 and the electrode 711 is joined to the bearing 714. The mover 712 includes an electrode 710 and an electrode 711.
With an appropriate gap between them. Therefore, the mover 712 can rotate between the opposing electrodes 710 and 711 about the axis 713. The electrode 711 is fixed to the substrate 720. Electrode 7
11 is electrically connected to the terminal 715. The electrode 710 is electrically connected to the terminal 716. However, the bearing 713 and the shaft 714 are electrically insulated.

In FIG. 14A, the mover 712
Is drawn out of the space created by the electrodes 710 and 711 forming the capacitor by an external force 730, and is at the least overlapped angle. As a result, the capacitance generated between the electrode 710 and the electrode 711 is the smallest.

On the other hand, in FIG. 14B, the mover 712 is inserted into the space formed by the electrode 710 and the electrode 711 forming the capacitor by the external force 730, and has the most overlapping angle. ing. Mover 712
Is made of a conductor or a material having a high dielectric constant, the capacitance generated between the electrode 710 and the electrode 711 becomes the largest.

As described above, by appropriately applying the external force 730, the capacitance of the capacitor shown in FIG. 14 can be changed. Therefore, by connecting the variable capacitor shown in FIG. 14 via the terminals 715 and 716 as shown in the electronic circuit of FIG. 1 and changing its capacitance by an external force 730, that is, by applying an external force 730 to FIG. By rotating the mover 712 so as to be in the overlapping condition as shown in FIG. 14A, and by rotating the mover 712 so as to be in the overlapping condition as shown in FIG. Energy can be extracted from the terminals 715 and 716.

Note that the number of divisions of the electrode and the movable member in the petal shape is not limited to four, but may be any number. However, the greater the number of divisions, the greater the change in capacitance with respect to the rotation angle.

Next, the dimensions of the electrode structure according to the eighth embodiment will be described. In the eighth embodiment,
Since the mover between the pair of electrodes is a conductor, a gap is required between the positive electrode and the negative electrode and the mover. The sum of the gaps is the minimum distance between the electrodes dmin (0.1 to 10 μm).
m). The size of the entire variable capacitor and the method of connecting a plurality of the capacitors are the same as in the sixth embodiment.

[Ninth Embodiment] The ninth embodiment is an example of a system in which the electrode surface is substantially widened. FIG. 15 is a diagram illustrating the configuration of a variable capacitor according to the ninth embodiment. In FIG. 15, the electrodes 810 and 8
A material having a microporous material such as activated carbon (hereinafter referred to as a microporous material) 8
12 and 813 are attached. Further, an insulating film 814 is provided on the surface of the microporous material 812 so that a short circuit does not occur even when they come into contact with each other. Electrodes 810 and 811 are electrically connected to terminals 820 and 821, respectively.

In the ninth embodiment, the capacitance is changed according to the principle described in FIG. 4 (change in the distance between the electrode plates).
Since the microporous material has a substantially very large surface area, the effective surface area is extremely large as compared with the surface area of the electrodes 811 and 812.

The variable capacitor shown in FIG. 15 is connected using the terminals 820 and 821 as shown in the electronic circuit of FIG. 1 and the electrodes 810 and 811 and the electrodes 810 and 811 are connected by an external force 831 as shown in FIG. Approaching the microporous materials 812 and 813 attached to them, or separating the electrodes 810 and 811 and the microporous materials 812 and 813 attached thereto by an external force 832 as shown in FIG. As a result, the capacitance between the terminals 820 and 821 greatly varies. Therefore, energy can be efficiently extracted from the terminals 820 and 821.

Although the ninth embodiment has been described in the form of changing the distance between the electrode plates, it is apparent that the present invention can be applied to any of the above-described methods.

The microporous relates to the properties of the electrode surface, and can be applied to all the electrodes used in the first to eighth embodiments. However, when sliding occurs on the electrode surface as in the fourth to eighth embodiments, the insulating material may be coated so that the surface becomes smooth.

[Tenth Embodiment] The first to ninth embodiments have been described above.
Various embodiments of the variable capacitor have been described according to the embodiments. By the way, as described with reference to FIGS. 1 to 3, in order for the capacitance-type power generation device according to the present embodiment to function independently and continuously, a configuration for supplying an electric charge to the capacitor 10 from the output side. Is required. In the tenth embodiment, a configuration for obtaining charge supply to a variable capacitor from an output side (charge storage unit) will be described.

FIG. 16 is a diagram for explaining a specific example of a method of obtaining a charge supply to the variable capacitor from the output side.
In FIG. 16, reference numeral 61 denotes a variable capacitor.
The capacitors described in the first to ninth embodiments are applied. A charge storage unit 63 includes a charge storage capacitor (or a secondary battery) 63b and a diode 63a for transferring charge from the variable capacitor 61 to the capacitor 63b. Also, 6
Reference numeral 2 denotes a charge supply unit, which is a DC-DC converter 62a.
And a switch 62b. The voltage V2 of the charge storage unit 63 is converted into the input voltage V1 with high efficiency by the DC-DC converter 62a, and is supplied to the variable capacitor 61 via the switch 62b. The switch 62
b is linked with the electrode displacement of the variable capacitance type capacitor 61 and is turned on when the capacitance of the variable capacitance type capacitor 61 becomes maximum. The switching timing of the switch 62b is controlled by a SWON signal from the DC-DC converter 62a, and the details of the control will be described later.

The switch 62b has a function similar to that of the diode 53 shown in FIG. 1, and when the loss due to the diode is sufficiently negligible (Vd <<V2; Vd
Is the forward voltage drop of the diode), the switch 62d may be replaced with a diode.

The electric charge of the variable capacitance type capacitor 61 when the capacitance is maximized is Q1 = C1 · V1. When the capacitance of the variable capacitance type capacitor decreases and the voltage starts to exceed the voltage V2 of the charge storage unit 63, the variable capacitance The charge of the mold capacitor 61 starts to move to the charge storage unit 63. When the capacitance of the variable capacitor 61 finally reaches the minimum value of C2, the charge Q2 remaining in the variable capacitor 61 is expressed by Q2 = C2 · V2. As a result, the charge that has moved to the charge storage unit 63 is as follows: Qg = Q1-Q2.

On the other hand, since Q2 is maintained until the capacitance of the variable capacitor 61 becomes maximum, the charge Qo to be output from the DC-DC converter 62a becomes equal to the above-mentioned Qg, and is expressed by Qo = Q1-Q2. You. This is a natural result from the law of conservation of charge.

The DC-DC converter 62a converts a part Qgp of Qg into Qo according to the following relationship. That is, Qo = Qg = η (V2 / V1) Qgp. Here, η is the conversion efficiency of the DC-DC converter 62a. It can be seen that if η is brought close to 1 and V2 is made sufficiently large with respect to V1, the power generation efficiency of the entire electrostatic generator increases.

FIG. 17 shows a DC-D according to the tenth embodiment.
It is a figure showing an example of C converter 62a. DC-DC
The converter 62a includes n flying capacitors 71
-1 to 71-n, n series connection switches 72-1 to 71-n
72-n, n parallel connection switches 73-1 to 73-
n, n-1 common connection switches 74-1 to 74-
n-1.

It is desirable that all of the n flying capacitors of the DC-DC converter have the same capacitance. If one of the capacitances is C, the total capacitance is C / n when connected in series. Therefore, the electric charge amount q2 stored in this becomes: q2 = C · V2 / n. In parallel connection, the entire capacitance of the flying capacitor is n · C, and the amount of charge q1 stored is q1 = n · C · V1. Further, since V1 = V2 / n, the charge gain is q1 / q2 = n.

When the series connection switches 72-1 to 72-n are on, the parallel connection switches 73-1 to 73-n and the common connection switches 74-1 to 74-n-1 are off, and the flying capacitor 71-1 to 71-n are connected in series. Conversely, series connection switches 72-1 to 72
When -n is off, the switches 73-1 to 73 for parallel connection
-N and the common connection switches 74-1 to 74-n-1 are turned on, and the flying capacitors 71-1 to 71-n are turned on.
Are connected in parallel.

The control circuit 75 includes the variable capacitor 6
When the capacitance of No. 1 is the maximum, the flying capacitors 71-1 to 71-n are switched to the parallel connection side at the same time when the switch 62b is turned on to supply the electric charge to the variable capacitance type capacitor 61. At the same time as the displacement of the variable capacitor 61 is started, the flying capacitors 71-1 to 71-n
Is switched to the series connection side, and the variable capacitor 61
Is obtained from the charge storage unit side.
In order to operate this system stably, it is necessary to apply the voltage V2 of the charge storage unit to the initial state by other means, but the subsequent operation is performed by the power generated by the system itself.
Can be done completely independently.

As described above, when the capacitance of the variable capacitor 61 is the maximum, the switch 62b is turned on,
The connection of the flying capacitor is switched, and this control is performed by the control circuit 75. In order to detect that the capacitance has become maximum, the variable capacitor 6
A method using an off-the-shelf sensor for detecting that the distance between the electrodes 1 is minimized is also conceivable. However, as a form utilizing the characteristics of the system, the voltage between the electrodes of the variable capacitor 61 becomes V1 (see FIG. 3). Voltage is V
In the state of 1, the capacitance of the capacitor changes from C0 to C0 + .DELTA.C. During this time, there is no problem even if the switch 62b is on.

FIG. 18 is a diagram showing a detailed circuit configuration example of the control circuit 75. In this circuit, the comparator 90
The voltage Vc of the variable capacitor is connected to the minus side input of 1 and the output Vref of the reference voltage generating circuit 905 is connected to the plus side input. As Vref, the desired secondary output voltage is V2
If it is set to 0, Vref = V20 / n is set. The output PSEL of the comparator 901 is connected to the parallel connection side switches 73-1 to 73-n,
74-1 to 74-n-1.
Further, the output PSEL is inverted by the inverter 904 to become the SSEL, and the series connection side switch 7 in FIG.
3-1 to 73-n and 74-1 to 74-n-1. The other input of the comparator 902 is connected to the parallel connection switch output V1 to the negative input, and the output Vref of the reference voltage generation circuit 905 is connected to the positive input. The output of the comparator 902 passes through the gate 903 and
6 is connected to the control input (SWON) of the switch 62b. This signal is valid only when the output of the comparator 901 is at the H level, that is, when the parallel connection switch is on.

The limiter 906 protects the input of the comparator when the voltage of the variable capacitor 61 increases to a high level, and does not affect the control operation.

When the voltage of the variable capacitor 61 is Vref
When the voltage falls below the threshold (point d in FIG. 3), the output of the comparator 901 becomes H level, and the flying capacitor of the DC-DC converter switches from series connection to parallel connection. At this time, a voltage of V2 / n appears at V1. This V1
Is compared with the reference voltage Vref by the comparator 902. When V1 <Vref, the switch 62b is turned on, and when V1> Vref, the switch 62b is kept off. Variable capacitor 6
1 further increases the capacitance until the point a in FIG. 3 is reached. If the switch 62b is on, the charge supply source (DC-D
C converter).

Even when the switch 62b is off, the voltage continues to decrease in the process of increasing the capacitance of the variable capacitor until the point a in FIG. 3 is reached, so that the voltage may become lower than Vref. The output of the comparator 902 becomes H level at that time, turning on the switch 62b, and the electric charge from V1 is supplied to the variable capacitor.

When the state of the system passes a point a in FIG. 3, the voltage of the variable capacitor 61 decreases, and the voltage increases.
The outputs of the comparators 901 and 902 become L level,
The switch 62b is turned off. The amount of charge transferred from the charge supply source V1 to the variable capacitor is the secondary output V
2 is controlled according to the level of V2
Work to maintain.

As described above, according to the above embodiment, the capacitance per unit volume is greatly increased by miniaturizing the power generation mechanism of the variable capacitance type electrostatic power generation to the micrometer range, and A structure capable of changing the capacitance with a small force is adopted. As a result, the area of the electrode existing in a unit volume can be greatly increased. Further, since the capacitance is proportional to the surface area, the generated energy density can be dramatically increased. Furthermore, since the capacitance is increased even when the thickness is reduced, the amount of energy that can be generated is greatly increased. The large quantitative changes have the potential to result in qualitative changes in the use of conventional generators.

On the other hand, in the case of a magnetic field type generator, the magnetic force is proportional to the volume, so that even if the generator is miniaturized, the energy density does not increase. On the contrary, the efficiency decreases due to the leakage of magnetic flux and the energy density decreases. For this reason, the size is simply reduced, but according to the variable capacitance type electrostatic power generation system of the present embodiment, it is possible to obtain an energy density equal to or higher than that of the magnetic field type.

In the electrostatic power generation, power is generated by changing the positional relationship between elements forming a capacitor by some force and changing the capacitance. According to the above embodiments, at least one of the interval between the electrodes constituting the capacitor or the interval between the electrode and the dielectric is set to 100 μm.
By miniaturizing the power generation mechanism, power can be generated with a small force that has not been used conventionally. That is, it is possible to generate power even by using energy having a large entropy in nature and poor quality, such as ground vibration, fluid-related vibration, body motion, and thermal disturbance.

That is, a small external force (kinetic energy)
A variable capacitance capacitor that produces a change in capacitance is formed by laminating or connecting in parallel, so it can handle large displacements and uses poor-quality energy with random force direction, amplitude, and phase. To generate electricity. In addition, such random kinetic energy is
Although the direction of the movement is random, the movement is a reciprocating movement. For this reason, among the above embodiments, those that can be driven by linear motion can use the kinetic energy as mechanical primary energy as it is. Those requiring a rotational motion need to temporarily convert the kinetic energy into a rotational motion.

Further, since usable energy exists under a normal environment, there are few restrictions on the usable environment. Therefore, replenishment for obtaining primary energy is not required, and the system can be operated as an autonomous system for a very long time. This makes it useful as a long-term monitoring of biological phenomena and as a power source for cardiac pacemakers and the like. In addition, since the power to be used may be small, noise generated during power generation does not occur.

Further, the basic unit of the power generating element must be miniaturized. By integrating this basic unit, it is possible to arbitrarily cope with a small output to an output having a size that can be used everyday. Can be. Further, since the basic unit is small, the shape after integration can be designed with considerable flexibility. This can contribute to the reduction in size and weight of the entire portable device, such as utilizing the dead space of the device or printing on a part of the case member.

In the electrostatic power generating device of the present invention, the larger the area of the quadrilateral abcd in FIG. 3, the larger the energy that can be obtained. This means that it is more advantageous to increase the maximum value of the capacitance at the point a and reduce the primary voltage V1. Assuming that the electrode area is fixed, increasing the capacitance requires reducing the distance between the electrodes. However, since V1 can be reduced in proportion to this, there is no problem with the withstand voltage (however, there is no problem with decreasing the capacitance). Since the voltage between the electrodes increases in the cycle, the method of reducing the capacitance by increasing the distance between the electrodes, as in the first to fourth embodiments, is more advantageous for providing withstand voltage. Is).

Here, when the distance between the electrodes is reduced and the primary side voltage V1 becomes a level which may be several tens of mV, a special power supply is not required as a charge supply source, and the electrode pair itself can be the charge supply means. To realize this, one of the electrode pairs needs to be a conductor, and the other has to be made of a metal different from the conductor or a different material such as a polymer. It is known that when different metals or different materials come into contact with a conductor, a contact potential is generated due to a difference in work function between the materials. The level is estimated to be about several tens of mV at the maximum, but it is sufficient to obtain an electric charge even if the voltage is small, so that the purpose of the present invention is met. Thus, by using the contact potential as the charge supply source, the charge supply unit of the system is simplified, and a more compact electrostatic power generation mechanism can be realized.

The shape and size of the variable capacitor according to each of the embodiments described above can be variously modified depending on the purpose and the material used, and are not particularly limited to any of the above embodiments. .

[0130]

As described above, according to the present invention,
Since the capacitance per unit volume has been greatly increased by miniaturizing the variable capacitance capacitor, and the capacitance has been made variable by a small external force, a portable electrostatic power generator suitable for various uses has been developed. Obtainable.

[0131]

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of an electrostatic power generation device according to an embodiment.

FIG. 2 is a diagram illustrating the basic operation principle of the electrostatic power generation device according to the present embodiment.

FIG. 3 is a diagram illustrating the basic operation principle of the electrostatic power generation device according to the present embodiment.

FIG. 4 is a diagram showing an example in which the capacitance is made variable by changing the distance between the electrode plates.

FIG. 5 is a diagram showing an example in which the capacitance is made variable by changing the electrode plate area.

FIG. 6 is a diagram showing an example in which the capacitance is made variable by changing the dielectric constant between the electrode plates.

FIG. 7 is a diagram illustrating a configuration of a variable capacitor according to the first embodiment.

FIG. 8A is a diagram illustrating a configuration of a variable capacitor according to a second embodiment.

FIG. 8B is a diagram illustrating a configuration of a variable capacitor according to the second embodiment.

FIG. 9A is a diagram illustrating a configuration of a variable capacitor according to a third embodiment.

FIG. 9B is a diagram illustrating the configuration of a variable capacitor according to the third embodiment.

FIG. 10 is a diagram illustrating a configuration of a variable capacitor according to a fourth embodiment.

FIG. 11A is a diagram illustrating a configuration of a variable capacitor according to a fifth embodiment.

FIG. 11B is a diagram illustrating the configuration of a variable capacitor according to a fifth embodiment.

FIG. 11C is a diagram illustrating the dimensions of the variable capacitor according to the fifth embodiment.

FIG. 12 is a diagram illustrating a configuration of a variable capacitor according to a sixth embodiment.

FIG. 13 is a diagram illustrating a configuration of a variable capacitor according to a seventh embodiment.

FIG. 14 is a diagram illustrating a configuration of a variable capacitor according to an eighth embodiment.

FIG. 15 is a diagram illustrating a configuration of a variable capacitor according to a ninth embodiment.

FIG. 16 is a diagram illustrating a specific example of a method of obtaining charge supply to a variable capacitor from an output side.

FIG. 17 is a diagram illustrating an example of a DC-DC converter 62a according to a tenth embodiment.

FIG. 18 is a diagram illustrating a detailed circuit configuration example of a control circuit 75.

FIGS. 19A and 19B show a configuration in which variable capacitors are connected in parallel. FIG.
It is a figure explaining the form where the minimum phase matches, (b)
FIG. 7 is a diagram illustrating a form in which the maximum and minimum phases in a change in the capacitance value of the capacitor are different.

Continued on the front page (72) Inventor Nobuyuki Kabui 2-29-203, Suehiro, Kumagaya-shi, Saitama Prefecture (72) Inventor Yoshizo Ishizuka 1500 Inoguchi, Nakai-machi, Ashigara-gun, Kanagawa Prefecture Within Terumo Corporation (72) Inventor Fuminori Tsuboi Kanagawa Inside Terumo Co., Ltd., 1500, Inokuchi, Nakai-machi, Ashigara-gun, Pref. (72) Inventor Kunimasa Katayama 1500, Inokuchi, Nakai-cho, Ashigaegami-gun, Kanagawa Prefecture, Terumo Corporation

Claims (15)

[Claims] 1. A variable capacitor in which a gap between elements contributing to determination of a capacitance is 100 μm or less, and a capacitance is changed by an external force; and the capacitance of the variable capacitor is increased by the external force. A supply means for supplying a charge to the variable capacitor with a first voltage; and a charge storage device for the variable capacitor when the capacitance of the variable capacitor decreases due to the external force. And an accumulating means for accumulating a part at a second voltage higher than the first voltage. 2. The electrostatic power generator according to claim 1, wherein the variable capacitor changes at least one of an inter-electrode distance, an electrode facing area, and a dielectric constant between the electrodes by an external force. 3. The electrostatic power generator according to claim 1, wherein the supply of the electric charge from the supply unit is performed using a part of the energy stored in the storage unit. 4. The variable capacitance capacitor according to claim 1, wherein the supply means supplies the variable capacitance capacitor with the first voltage when the capacitance of the variable capacitance capacitor reaches a maximum value. 3. The electrostatic power generating device according to claim 1. 5. The electrostatic power generation device according to claim 1, wherein the variable capacitor has an electrode plate supported by an elastic body, and the external force changes a distance between the electrodes. Machine. 6. The variable capacitor has a structure in which electrode sheets each having an electrode surface formed on an elastic thin film are laminated, each of the electrode sheets has a corrugated cross section, and the adjacent electrode has 2. The electrostatic power generating device according to claim 1, wherein the sheets are joined to each other at a vertex portion of the wave shape while being insulated from each other. 7. The variable capacitor according to claim 1, wherein an elastic body having a flat sectional shape is formed in a coil spring shape, and electrode surfaces insulated from each other are formed on both surfaces of the elastic body. 2. The electrostatic power generation device according to 1. 8. The electrostatic capacitor according to claim 1, wherein the variable capacitor is formed by spirally forming an electrode sheet having electrode surfaces insulated from each other on both surfaces of an elastic thin film. Generator. 9. The variable capacitor has two electrodes having a comb-like cross-sectional shape, and the two electrodes are arranged such that the teeth of the combs are alternately inserted, and at least one of the two electrodes is provided. 2. The electrostatic power generator according to claim 1, wherein one of the power generators is supported by an elastic body. 10. The variable capacitor according to claim 2, wherein the petal-shaped or stripe-shaped electrodes are formed radially.
The two flat plates have a structure in which they share a central axis and face each other, and one flat plate can rotate with respect to the other flat plate so as to cause a shift of at least の or more of the width of the electrode. The electrostatic power generator according to claim 1, wherein 11. The variable capacitor is provided between two opposing flat plates on which a plurality of electrodes are formed at predetermined intervals.
A movable element having a dielectric material disposed at the predetermined interval has a structure in which the movable element is movably inserted in parallel with the flat plate, and a non-dielectric material or a dielectric material having a low dielectric constant is interposed between the dielectric materials of the movable element. The electrostatic power generator according to claim 1, wherein a body material is disposed. 12. The variable capacitor according to claim 2, wherein the petal-shaped or stripe-shaped electrodes are formed radially.
The two electrode plates share a central axis and are arranged facing each other, and a dielectric plate in which a dielectric is formed in a petal or stripe shape from the center shares the central axis between the two electrode plates. 2. The electrostatic power generator according to claim 1, wherein the dielectric flat plate is rotatable about the central axis. 13. The electrostatic power generator according to claim 1, wherein the variable capacitor has a microporous structure on a surface of an electrode. 14. The electrostatic power generating device according to claim 1, wherein the variable capacitance type capacitor uses a material that causes contact charging when the electrodes are in contact with each other via an insulating film. 15. A plurality of variable capacitors whose capacitances are changed by an external force, and when the capacitance of the variable capacitors is increased by the external force, a charge is supplied to the variable capacitors by a first voltage. Supply means; and storage means for storing a part of the charge stored in the variable capacitor at a second voltage higher than the first voltage when the capacitance of the variable capacitor decreases due to the external force. Wherein the plurality of variable capacitance capacitors are connected in parallel to the supply means via first rectification means, and are connected in parallel to the storage means via second rectification means. Characteristic electrostatic power generator.