JP2003199313A - Vibrating generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in a vibrating generator wherein power genera tion efficiency lowers as input amplitude changes. <P>SOLUTION: This vibrating generator, which converts vibration from the outside into induced voltage in coils by supporting the coils and a permanent magnet so as to be capable of relative movement, comprises the permanent magnet 3, a plurality of coils 1a to 1c which receives at least part of the magnetic flux of the permanent magnet 3, connection parts 24-1, 24-2 which mutually connect all or one of the plurality of coils 1a to 1c, and a control part 25 which controls the connection of the plurality of coils 1a to 1c, based on the induced voltage generated in the plurality of coils 1a. The control part 25 regulates the whole inductance, even when the amplitude from the outside changes, thus, the relative movement of the maximum amplitude can be maintained, thus stabilizing the generated voltage. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration power generator that generates electric power using vibration of a machine or a person, and more particularly to a technique for improving power generation efficiency of the vibration power generator.

[0002]

2. Description of the Related Art In portable electronic devices such as mobile personal computers, securing a power source is a major issue. Batteries are generally used as a power source for these devices, but there is a problem in that a primary battery requires battery replacement and a secondary battery requires charging. On the other hand, there is a generator that can be incorporated into an electronic device as a power supply that does not require replacement or charging. In this type of generator, a user rotates a handle or a lever attached to a rotating shaft to generate electric power and supply the electric power to an electronic device. Although this type of generator does not require replacement or charging, it has the trouble of manually moving the handle. It is also possible to incorporate a solar cell or a temperature difference battery into an electronic device. If you use these, there is no need to change, charge, rotate the handle, etc., but the former cannot generate electricity in a place where the light does not hit, such as in the bag, the latter does not adhere to the heat source by fixing it directly to the skin. And cannot generate electricity. Nor can it be charged rapidly.

As a power source different from the above-mentioned battery, generator, solar battery and temperature difference battery, a vibration generator which automatically generates power by using the movement of a person or machine is used in a wristwatch or the like. The vibration generator has a semi-circular weight fixed to the rotating shaft,
A permanent magnet coupled to the rotating shaft and a coil provided in the vicinity of the permanent magnet are provided, and the permanent magnet is rotated after the rotation of the shaft due to the movement of a person or machine is accelerated by the gear train. To generate an induced voltage. When this generator is attached to an arm or the like, the weight rotates due to the movement of the arm, so that power can be obtained from the coil. Further, when the permanent magnet and the coil are coupled with a spring and vibration is applied from the outside, the coil and the permanent magnet move relative to each other, so that electric power can also be taken out from the coil.

[0004]

These vibration power generators have the advantages that they do not require the trouble of turning the handle, that they can be installed anywhere, and that they can be rapidly charged. However, the vibration power generator has an input amplitude that maximizes the power generation efficiency. On the other hand, the motion of a person or a machine does not have a constant amplitude, so that the power generation efficiency is significantly reduced depending on the usage conditions.

The present invention has been made to solve the drawback of the conventional vibration power generator, that is, the power generation efficiency is lowered when the input amplitude changes.

[0006]

A vibration power generator according to the present invention is a vibration power generator which supports a coil and a permanent magnet so that they can move relative to each other and converts vibration from the outside into an induced voltage of the coil. A permanent magnet, a plurality of coils that receive at least a part of the magnetic flux of the permanent magnet, a connecting portion that connects all or a part of the plurality of coils to each other, and an induction generated in one or a plurality of the plurality of coils. And a control unit that controls the connection of the plurality of coils based on the voltage.

Preferably, the control section compares the induced voltage generated in one or a plurality of the plurality of coils with a predetermined first voltage, and based on the comparison result, a part or a part of the plurality of coils. All of them are connected to each other, an induced voltage generated in one or a plurality of the plurality of coils is compared with a second predetermined voltage, and at least a part of the plurality of coils is disconnected based on the comparison result. , Controlling the connection.

Preferably, the first voltage value is the second voltage value.
Higher than the voltage value of.

Preferably, the first voltage value is generated when one of the plurality of coils and the permanent magnet relatively move in a maximum movable range in a sinusoidal manner at a dominant frequency of an external force. It is an induced voltage generated in one or more of the plurality of coils.

Preferably, the second voltage value is a sine wave at a maximum movable range of any one of the plurality of coils and the permanent magnet after the at least a part of the plurality of coils is cut off. It is an induced voltage generated in one or more of the plurality of coils in the case of relative movement.

Preferably, the natural frequency of the relative motion between the plurality of coils and the permanent magnet corresponds to the dominant frequency of the vibration applied from the outside.

For example, the connecting portion connects all or a part of the plurality of coils in series.

For example, the connecting portion connects all or part of the plurality of coils in parallel.

An oscillating power generator according to the present invention is a oscillating power generator which supports a coil and a permanent magnet so that they can move relative to each other and converts an external vibration into an induction voltage of the coil. A coil that receives at least a part of the magnetic flux of the magnet, an inductance varying unit that changes the inductance of the coil, a detection unit that detects the amplitude of relative motion of the permanent magnet and the coil, and the detection unit based on the output of the detection unit. And a control unit that changes the inductance of the coil.

Preferably, the controller controls the inductance of the coil such that the permanent magnet and the coil move relative to each other within a maximum movable range.

[0016] Preferably, the control unit increases the inductance of the coil when the amplitude of the relative movement is larger than a predetermined first value, and the control unit increases the inductance of the relative movement to a second predetermined value. When it is smaller than the value, the inductance of the coil is reduced, and the first value is larger than the second value.

The present invention always obtains the maximum power generation efficiency by changing the inductance of the coil in accordance with the input amplitude. For example, two or more coils of the generator are provided, the input amplitude is detected by the voltage generated by the coils, and the connection of the coils is switched to change the inductance (effective number of turns).

For example, when the amplitude of the vibrating body is gradually increased and the voltage generated by the first coil reaches a certain value (this voltage is called the first voltage value), the second coil is connected and effective. Increase the number of turns. Then, the amplitude of the vibrating body once decreases, and the voltage generated by the first coil also decreases. When the input amplitude further increases, the voltage generated in the first coil increases again. When the voltage of the first coil becomes equal to the first voltage value, the third coil is connected. Hereinafter, a coil is added every time the voltage of the first coil reaches the first voltage value. The reason why the connection is made only by the voltage value of the first coil is that the generated voltage of the first coil is proportional to the amplitude of the vibrating body, regardless of the number of coils.

For example, the input amplitude decreases and the voltage generated by the first coil has a certain value (this voltage is called the second voltage value).
When it reaches, disconnect one coil. Then, the amplitude of the vibrating body once increases, and the voltage generated by the first coil also increases. When the input amplitude further decreases, the voltage generated in the first coil decreases again. And the voltage of the first coil is the second
When it becomes equal to the voltage value of, the third coil is disconnected.
Hereinafter, one coil is disconnected each time the voltage of the first coil reaches the second voltage value. The second voltage needs to be determined for each set of coils after disconnection. This is because the amplitude after disconnection changes depending on the combination of coils after disconnection.

For example, for the same input amplitude, the smaller the damping is, the higher the power generation efficiency is. Therefore, the smaller the maximum movable width is, the smaller the number of coils is. If the input amplitude is large and the coil amplitude exceeds the maximum movable width, the coil may collide with the case and cause damage, so it is better to lower the amplitude. From the above, it is optimal to add a coil when the coil amplitude matches the maximum movable range.

For example, after disconnecting one coil, the coil is disconnected at an external force amplitude in which the relative amplitude of the first coil and the permanent magnet is in the maximum movable range. The reason why collision does not occur before and after disconnection and the efficiency becomes maximum is when the coil amplitude after disconnection matches the maximum movable range.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of a vibration power generator will be described. The structure of a typical vibration power generator is shown in FIG.
FIG. 10 shows a cross section of the vibration generator. 4 permanent magnets 3a
3 to 3d are fixed to two iron yokes 2a and 2b. The yokes 2a and 2b are connected by the non-magnetic spacers 4a and 4b, and the whole of them is supported by the base 6 via the leaf springs 5a and 5b. The coil 1 is inserted in the gap between the yokes 2a and 2b. The coil 1 is rigidly fixed to the base 6. When vibration is applied to the base 6 from the outside in the direction of the arrow in the figure, the permanent magnets supported by the leaf springs 5a and 5b vibrate left and right to change the magnetic flux penetrating the coil 1, and as a result, a voltage is induced in the coil 1. To be done.

The vibration generator of FIG. 10 is represented by an equivalent dynamic model as shown in FIG. Weight 10 in a rigid case 13
There is a case 1 with a spring 11 and a damper 12.
3 is supported inside. An electromagnetic induction portion including the coil 1 and the permanent magnets 3a to 3d in FIG. 10, the permanent magnet 3a
3d, iron yokes 2a and 2b, and non-magnetic spacer 4a,
The total inertia of 4b and the leaf springs 5a and 5b are respectively shown in FIG.
1 corresponds to the damper 12, the weight 10 and the spring 11. The amount of power generation is given by the energy consumed by the damper 12.

In the model of FIG. 11, when the case 13 is excited with the displacement amplitude Ao and the frequency ω, the energy consumption W per one cycle of vibration is given by the following equation. W = πCωA ² (1)

Here, A is the relative amplitude between the case and the vibrating body, and C is the damping coefficient of the damper 12. Consider maximizing W in equation (1). W is larger as CA ² is larger. Since A becomes maximum in the resonance state, it is first necessary to match the natural frequency of the vibrating body with the frequency ω of the external force. Next, C and A are inversely proportional in the resonance state. Therefore, CA ² increases as C decreases and A increases. But A
Has an upper limit and cannot exceed the movable width of the vibrating body in the case. Therefore, C may be set so that the vibrating body vibrates in the full movable width. In the vibration generator of FIG. 10, C can be changed by changing the number of turns of the coil. Also C
If is known, the amplitude A of the vibrating body can be known from W, that is, the induction voltage of the coil.

First Embodiment of the Invention The vibration generator according to the first embodiment of the present invention is shown in FIG. In case 13,
A permanent magnet 3 having a U-shaped cross section is provided. This can be moved left and right by the linear guide 14. When no external force is applied, the spring 11 holds the permanent magnet 3 near the center of the case 13. An iron yoke 2 is provided above the permanent magnet 3 so as to face the permanent magnet 3. A coil 1a, a coil 1b, and a coil 1c are wound around the yoke 2. The yoke 2 is fixed to the case 13. When the case 13 vibrates due to an external force, the inner permanent magnet 3 moves to the left and right, and the relative positional relationship between the permanent magnet 3 and the yoke 2 changes.
The magnetic flux passing through 1c changes.

A rectifying diode 20 is connected to one terminal of the coil 1a. The terminal 1A of the switch 24-1 is connected to the other terminal of the coil 1a, and the capacitor 21 is connected via the common terminal 1C of the switch 24-1.
It is connected to the. The other end of the diode 20 is connected to the other terminal of the capacitor 21 and the input end of the constant voltage circuit 22. The power from the coils 1a to 1c is stored in the capacitor 21. The constant voltage circuit 22 is the capacitor 2
1 is used as a power source to generate a DC voltage of, for example, 5 V to drive the external load 23. In addition, in order to increase the amplitude of the permanent magnet 3, it is desirable that its natural frequency be matched with the frequency ω of the external force.

The switch 24-1 connects either one of the terminals 1A and 1B to the terminal 1C. The switch 24-2 connects either one of the terminals 2A and 2B to the terminal 2C. The terminal 1A of the switch 24-1 is connected to one terminal of the coil 1b. The coil 1b is connected in series with the coil 1a. Similarly, the other end of the coil 1b and one terminal of the coil 1c are connected to the terminal 2A of the switch 24-2. The other end of the coil 1c is connected to the other terminal 2B of the switch 24-2. The common terminal 2C of the switch 24-2 is connected to the other terminal 1B of the switch 24-1. In this way, the coils 1a to 1c are connected in series and the switch 2 connected to the coils 1a to 1c.
4-1 and 24-2 are also connected in series. Switch 2
By appropriately switching 4-1 and 24-2, only the coil 1a is used (the switch 24-1 is set to the terminal 1).
When A is selected), the coils 1a and 1b are used (switch 24-1 selects terminal 1B, switch 2).
4-2 selects 2A), or any state of using all of the coils 1a to 1c (when switch 24-1 selects terminal 1B and switch 24-2 selects terminal 2B) Can be taken.

The control circuit 25 measures the voltage level between the terminal A of the coil 1a (common terminal of the coils 1a to 1c) and the terminal 1A, that is, the output voltage of the coil 1a, and internally performs a logical operation based on the measurement result. And the switch 24-1 and the switch 24-2 are switched based on the result. The control circuit 25 operates by receiving electric power from the output of the constant voltage circuit 22. A processing flowchart of the control circuit 25 is shown in FIG.

In FIG. 2, S3 and S4 are steps for comparing the level of the output voltage of the coil 1a with a predetermined threshold value. S3 and S4 determine the amplitude of the relative motion. The coils 1a to 1c are appropriately selected according to the determination result. S5 to S7 are steps for connecting 1b to the coil 1a in series, and S8 to S10 are coils 1a to
1c is a step for connecting 1c in series.
S3 is a step for disconnecting the coil 1c, and S3
14 to S16, the coil 1b is further separated to remove the coil 1
This is a step for using only a. From another point of view, S5 to S10 are steps for increasing the number of coils to be connected when the amplitude increases, while S11 to S10
S16 is a step for reducing the number of coils to be connected when the amplitude decreases. In short, the process of FIG. 2 judges whether the amplitude is increasing or decreasing based on the output voltage of the coil 1a, and when it is increasing, the coils are connected in series according to the degree. When the number of coils is decreasing, the number of connected coils is decreased according to the degree.

The operation of the vibration power generator according to the first embodiment of the invention will be described. The vibration power generator according to the first embodiment of the present invention is preferably installed in a machine whose frequency is constant and whose amplitude changes. For example, a tunnel excavator having a rotating part is applicable. A case where the vibration waveform of the case 13 is as shown in FIG. 3A will be described. It is assumed that the vibration starts at time t ₁ , the amplitude gradually increases, reaches the maximum at time t ₄ , decreases thereafter, and stops at time t ₇ .

Initially, the switch 24-1 changes the terminal 1A to
The switch 24-2 selects the terminal 2A. When vibration is applied from the outside, the permanent magnet 3 vibrates left and right. As a result, the yoke 2 and the coils 1a to 1c move relative to the permanent magnet 3, so that an induced voltage is generated across the coil 1a. Then, the electric charge is accumulated in the capacitor 21, and the voltage between the terminal B (terminal of the capacitor 21 on the diode 20 connection side) and the terminal 1C (the other end of the capacitor 21) rises. A constant DC voltage is output. As a result, the control circuit 2
5 starts.

The control circuit 25 switches between the switch 24-1 and the switch 24-2 according to the algorithm shown in FIG. Specifically, it is as follows.

S1: The control circuit 25 has thresholds V _on and V in advance.
_off1, V _off2 has been set. V _on is the threshold at the time of increased amplitude, V _off1 and V _off2 is the threshold at the time the amplitude decreases. Typically, a _{V on> V off1> V off2} . V in the first stage
_off = V _off1 .

S2: Measure the voltage envelope V _i between the terminals A and 1A. The voltage V _i between the terminals A and 1A changes as shown in FIG. 3B, and its envelope is given by the dotted line in the figure.

S3: Compare V _i with a threshold V _on . Immediately after the start of vibration, the coil 1a responds to the increase in the case vibration
The induced voltage of V increases and V _i also increases. Becomes a certain time t _2, the amplitude of the yoke is equal to the movable portion amplitude. At this time, the induced voltage generated by the coil 1a is V _on . The value of V _on is stored in the control circuit 25 in advance.

S5 to S7: The control circuit 25 causes V _i at time t _2.
When it is recognized that V is larger than V _on , the switch 24-1 is tilted to the terminal 1B side. Then, the coil 1a and the coil 1b are connected in series, and the inductance doubles,
The vibration of the yoke 2 is braked. For this reason, at time t _2, V _i is rapidly lowered. Also, the coil 1a and the coil 1
The total value of the induced voltage of b, that is, the voltage between the terminals A and 1C (FIG. 3C) also decreases. This is because when the case amplitude is the same, the larger the yoke amplitude, the larger the induced voltage. After that, the processes of steps S2 and S3 are repeated.

S8-S10: When the case amplitude further increases, the yoke amplitude again increases, and at time t ₃ , V _i returns to V _on again.
Reach Then, the control circuit 25 turns the switch 24-2 to the switch 2B side. Then, the coil 1a and the coil 1
b and the coil 1c are connected in series, the inductance further increases, and the vibration of the yoke is damped. Therefore, at time t ₃ , V _i sharply drops. The voltage between terminals A and 1C also drops. After that, the processes of steps S2 and S3 are repeated.

S11 to S13: When the case amplitude further increases and then starts to decrease, V _i also decreases. At time t ₅ , V _i becomes equal to V _off2 . Then, the control circuit tilts the switch 24-2 to the terminal 2A side. Then coil 1
c is disconnected, and only the coils 1a and 1b are connected to the capacitor 21. Then, the inductance is reduced, damping of the vibration of the yoke 2 is weakened, and the yoke amplitude is increased. Therefore, at time t ₅ , V _i rises sharply. At this time, so that the yoke amplitude matches the movable width,
V _off2 is set. That is, if the coil 1c is disconnected at this voltage, V _off2 increases the amplitude of the relative motion between the coil 1 and the permanent magnet 3 due to the decrease in inductance, and as a result, the amplitude matches the maximum movable range (movable range). Decided to do. V _off2 is stored in advance in the control circuit. The voltage between terminals A and 1C also rises.
After that, the processes of steps S2 and S3 are repeated.

S14-S16: When the case amplitude further decreases, the yoke amplitude again decreases, and at time t ₆ , V _i changes to V _off1.
Reach Then, the control circuit tilts the switch 24-1 to the switch 1A side. Then, the coil 1b is separated,
Only the coil 1a is connected to the capacitor 21. Then the inductance decreases and the yoke amplitude increases. For this reason, at time t _6, V _i rises rapidly. At this time, set V _off1 so that the yoke amplitude matches the movable width.
Is set. That is, in V _off2 , if the coil 1b is separated by this voltage and only the coil 1a is used, the amplitude of the relative movement between the coil 1 and the permanent magnet 3 increases due to the reduction of the inductance, and as a result, the amplitude is in the maximum movable range ( Movable range) is determined to match. V _off1 is stored in the control circuit in advance. Also, at time t ₆ , terminal A / 1C
The voltage between them also rises once.

When the case amplitude further decreases, the induction voltage of the coil decreases again, and eventually the output of the constant voltage circuit 22 stops and the control circuit 25 also stops.

The voltage across the terminals of the capacitor 21 is shown in FIG.
It changes like (d). The higher the voltage between terminals A and 1C, the faster the charge.

The above operation will be compared with the conventional vibration generator. Since the output of the generator is determined by the voltage of the capacitor, compare the envelopes of the voltage between terminals A and 1C. Figure 4 (a)
Shows the case amplitude, FIG. 4 (b) shows the voltage between the terminals A and 1C in the embodiment of the present invention, and the solid line in FIG. 4 (c) shows the voltage between the terminals A and 1C when only the coil 1a is used. (Dashed line indicates the graph of FIG. 4B), and FIG.
The solid line indicates the terminal A when the coils 1a to 1c are connected in series.
-The voltage between 1C is shown (the dotted line shows the graph of FIG. 4B). All show only the envelope. 4C and FIG.
(D) corresponds to the conventional method.

FIG. 4B and FIG. 4 in the case of only the coil 1a
Comparing (c), the voltage according to the embodiment of the present invention and the voltage according to the conventional method are the same from time t ₁ to time t ₂ . However, in the case of FIG. 4C, the voltage has reached a peak between time t ₂ and time t ₆ and does not increase. This is because the yoke 2 vibrates while colliding with the case 13, and the amplitude does not increase. On the other hand, in the case of FIG. 4B, the voltage increases,
It peaks at time t ₄ . Since the yoke 2 vibrates without colliding with the case 13 after the time t _6, the graph of FIG. 4B and the graph of FIG. 4C are the same. After all, time t ₂
It can be seen that from time t ₆ to time t ₆ , the device according to the embodiment of the present invention can generate a higher voltage and is superior to the conventional method.

Comparing FIG. 4 (b) with FIG. 4 (d) when three coils are connected in series from the beginning, time t ₃ to t ₅
During the period, the device according to the embodiment of the present invention and the conventional device have the same inductance and the same voltage. But the time
Between t ₁ and t ₃ and between times t ₄ and t ₆ , the inductance of the conventional device, that is, the braking force acting on the yoke is large. Therefore, at these times, the conventional device is inferior to the device according to the embodiment of the present invention shown by the dotted line in FIG.

When the case amplitude is small, the device according to the embodiment of the present invention will be compared with the conventional vibration generator. 5A is a case amplitude, FIG. 5B is a voltage between terminals A and 1C according to the embodiment of the present invention, and FIG. 5C is a voltage between terminals A and 1C when only one coil is used. Figure 5
(D) is the voltage between terminals A and 1C when three coils are connected in series from the beginning. These figures show the case where the case amplitude is small, and the coil connection switching does not occur in the embodiment of the present invention, that is, the case where V _i does not reach V _on . In this case, since only one coil is used, FIG.
The voltage in (b) and the voltage in FIG. 5 (c) are the same. on the other hand,
The voltage generated when the coils 1a to 1c in FIG. 5D are connected in series is lower than that in the case of FIG. 5B or 5C because the braking force acting on the yoke is large and the yoke hardly vibrates. .

As described above, according to the embodiment of the present invention, it is possible to generate a higher voltage regardless of whether the amplitude is large or small.

Since the control circuit 25 is driven, the output finally obtained in the embodiment of the present invention is obtained by subtracting the power consumption. The function of the control circuit is
It is to extract the envelope from the oscillating voltage and to switch the switch based on the voltage value. The former is AM
This is the same as the detection, and can be composed of only passive elements. In the latter case, the switching frequency is as low as once every few seconds, so the calculation may be slow and can be sufficiently realized by a microprocessor with power consumption of 1 mW or less. On the other hand, vibration generators with a size of about 10 cm square and an output of 20 mW to 1 W are manufactured. Therefore, the loss due to the control circuit 25 is so small that it can be ignored.

Second Embodiment of the Invention First Embodiment of the Invention
Was to add coils in series according to the magnitude of vibration amplitude. The present invention is not limited to this, and can be applied to the case of adding coils in parallel connection.

FIG. 6 shows an apparatus according to the second embodiment of the present invention. Inside the case 13, there is a permanent magnet 3 of the following shape, which can be moved left and right by a linear guide 14. Further, it is held near the center of the case 13 by the spring 11. Above the permanent magnet 3, there is an iron yoke 2 around which the coil 1a, the coil 1b, and the coil 1c are wound. A diode 20 is connected to one terminal of the coil 1a, and a capacitor 21 and a constant voltage circuit 22 are further connected. The constant voltage circuit 22 has, for example, 5
A DC voltage of V is generated to drive the external load 23. One terminal of each of the coil 1b and the coil 1c is the coil 1a.
, And the other terminal is connected to the switch 26-1 and the switch 26-2. The control circuit 25 drives the output of the constant voltage circuit 22 as electric power. Terminal A / C
The voltage level between them is measured, a logical operation is internally performed, and the switch 26-1 and the switch 26-2 are switched.

FIG. 7 is a control flowchart of the control circuit 25.
Shown in. The operation of the apparatus according to the second embodiment of the invention will be described. It is assumed that the case amplitude changes as in FIG. Initially, the switch 26-1 and the switch 26-2 are open. When vibration is applied from the outside, the yoke 2 moves relative to the permanent magnet 3 and an induced voltage is generated in the coil 1a. Then, electric charges are accumulated in the capacitor 21, and when the voltage between the terminals B and C becomes a certain value or more, the constant voltage circuit 22 outputs a constant DC voltage. This activates the control circuit 25.

Inside the control circuit, the switch 26-1 and the switch 26-2 are switched by the algorithm of FIG. First, the voltage envelope V _i between the terminals A and C is measured. The voltage between terminals A and C changes in substantially the same manner as in FIG. 3B shown in the first embodiment. When the relative amplitude of the yoke is equal to the amplitude of the movable part, the induced voltage generated by the coil 1a is set to V _on.
And When the control circuit recognizes that V _i has become equal to V _on , it closes switch 26-1. Then, the coil 1a and the coil 1b are connected in parallel, and the inductance is 2
Doubled. Immediately after this, V _i drops once.

The case amplitude further increases, and V _i becomes V _on again.
Control circuit 25 closes the switch 26-2. Then, the coils 1a to 1c are connected in parallel, and the inductance further increases.

When the case amplitude further increases and then decreases, V _i also decreases. When V _i equals V _off2 , control circuit 26 opens switch 26-2. Then coil 1
c is disconnected, and only the coils 1a and 1b are connected to the capacitor 21. At this time, the yoke amplitude increases once. V _off2 is set so that the yoke amplitude after separation becomes equal to the movable width.

When the case amplitude further decreases, V _i becomes V
reaches _off1 . Then, the control circuit 25 causes the switch 26-
Open one. Then, the coil 1b is disconnected, and the coil 1b
Only a is connected to the capacitor 21. V
_off1 is set so that the yoke amplitude after separation becomes equal to the movable width.

When the case amplitude further decreases, the induction voltage of the coil decreases again, and eventually the output of the constant voltage circuit 22 stops and the control circuit 26 also stops.

The voltage across the terminals of the capacitor 21 also changes with a waveform similar to that of FIG. 3 (d) shown in the first embodiment. Similar to the first embodiment, the voltage between the terminals A and C is higher than in the case of only the conventional coil 1 and in the case where the coils 1, 2, and 3 are fixedly connected in parallel.

Third Embodiment of the Invention In the first and second embodiments of the present invention, the coils are switched based on the voltage of the coil 1a. The present invention is not limited to this. Other means for detecting the amplitude of the relative motion, such as a switch provided near the maximum amplitude or a switch provided at a predetermined place, can be used. Also, instead of a switch as a means of changing the inductance,
For example, a contact that slides on the coil can be used.

FIG. 8 shows the configuration of a general vibration power generator to which the present invention is applied. This is the n coils 1-1 to 1-
n, and the inductance varying means 27 appropriately connects them based on the output of the amplitude detector 28 to change the overall inductance. The control unit 25 determines the inductance by referring to the determination information previously written in the amplitude-inductance increase / decrease table 25a.

The following data, for example, is written in the table 25a. Amplitude Inductance increase / decrease A0 (maximum amplitude) Inductance increase by ΔL0 A1 Inductance decrease by ΔL1 A2 Inductance decrease by ΔL2

Or     Amplitude Amplitude change Inductance increase / decrease     Increase A0 (maximum amplitude) Increase inductance by ΔL0     A1 decrease Inductance decreased by ΔL1

FIG. 9 shows a processing flowchart in the third embodiment of the invention.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. It goes without saying that this is what is done.

Further, in the present specification, the means does not necessarily mean a physical means, but also includes the case where the function of each means is realized by software.
Further, the function of one means may be realized by two or more physical means, or the functions of two or more means may be realized by one physical means.

[0065]

As described above, according to the present invention,
In the vibration power generator, the inductance of the coil is changed based on the induced voltage and / or the amplitude of relative motion between the permanent magnet and the coil, so that power generation efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a vibration power generator according to a first embodiment of the invention.

FIG. 2 is an operation flowchart of the control circuit according to the first embodiment of the invention.

FIG. 3 is a graph of case vibration and voltage waveform of the vibration power generator according to the embodiment of the invention.

FIG. 4 is a graph of envelope curves of case vibration and voltage waveform when the vibration amplitude is large.

FIG. 5 is a graph of case vibration and an envelope of a voltage waveform when the vibration amplitude is small.

FIG. 6 is a schematic diagram of a vibration power generator according to a second embodiment of the invention.

FIG. 7 is an operation flowchart of the control circuit according to the second embodiment of the invention.

FIG. 8 is a schematic diagram of a vibration power generator according to a third embodiment of the invention.

FIG. 9 is an operation flowchart of the control circuit according to the third embodiment of the invention.

FIG. 10 is a schematic diagram of a conventional vibration power generator.

FIG. 11 is a diagram showing a dynamic model of the vibration power generator.

[Explanation of symbols]

1 coil 2 York 3 permanent magnet 4 Non-magnetic spacer 5 leaf spring 6 base 10 weights 11 springs 12 damper 13 cases 14 Linear guide 20 diodes 21 capacitor 22 Constant voltage circuit 23 External load 24 switches 25 Control circuit 26 switch 27 Inductance changing means 28 Amplitude detector

   ─────────────────────────────────────────────────── ─── Continued front page    (71) Applicant 500235179             Kiyo Itao             6-6-8 Jomyoji Temple, Kamakura City, Kanagawa Prefecture (71) Applicant 501496717             Ken Sasaki             2-4-9 Shin-Kashiwa, Kashiwa City, Chiba Prefecture (72) Inventor Hiroshi Hosaka             Chiba Prefecture Matsudo City Matsudo 159-1-2-302 (72) Inventor Jun Okazaki             1-59-6 Ogikubo, Suginami-ku, Tokyo (72) Inventor Kenji Shiba             Five Steps, Iwabuchi 25-21, Kita-ku, Tokyo             No. 202 (72) Inventor Kiyoshi Itao             6-6-8 Jomyoji Temple, Kamakura City, Kanagawa Prefecture (72) Inventor Ken Sasaki             2-4-9 Shin-Kashiwa, Kashiwa City, Chiba Prefecture F-term (reference) 5H590 AA02 CA18 CA24 CC02 CC24                       CC32 EB02 FA05 FB01 FC26                       GA02 GB05 HA02 JA03

Claims (11)

[Claims] 1. A vibration generator for supporting a coil and a permanent magnet so that they can move relative to each other and converting an external vibration into an induction voltage of the coil, wherein the permanent magnet and at least a part of a magnetic flux of the permanent magnet. Receiving a plurality of coils, a connecting portion for connecting all or a part of the plurality of coils to each other, and a control for controlling the connection of the plurality of coils based on an induced voltage generated in one or a plurality of the plurality of coils. And a vibration generator. 2. The control unit compares an induced voltage generated in one or a plurality of the plurality of coils with a predetermined first voltage, and based on a result of the comparison, a part or all of the plurality of coils. Are connected to each other, the induced voltage generated in one or a plurality of the plurality of coils is compared with a second predetermined voltage, and at least a part of the plurality of coils is disconnected based on the comparison result, The vibration power generator according to claim 1, wherein the connection unit is controlled. 3. The vibration generator according to claim 2, wherein the first voltage value is higher than the second voltage value. 4. The one of the plurality of coils, wherein the first voltage value is generated when one of the plurality of coils and the permanent magnet relatively move in a sinusoidal manner within a maximum movable range at a dominant frequency of an external force. Alternatively, the vibration power generator according to claim 3, which is an induced voltage generated in a plurality of parts. 5. The second voltage value has a sine wave shape in which a maximum moving range of one of the plurality of coils and the permanent magnet is within a maximum movable range at a predominant frequency of an external force after at least a part of the plurality of coils is cut off. The vibration power generator according to claim 3, wherein the vibration generator is an induced voltage generated in one or a plurality of the plurality of coils when exercising. 6. The vibration generator according to claim 1, wherein the natural frequency of the relative motion between the plurality of coils and the permanent magnet matches the dominant frequency of the vibration applied from the outside. 7. The vibration power generator according to claim 1, wherein the connecting portion connects all or part of the plurality of coils in series. 8. The vibration power generator according to claim 1, wherein the connecting portion connects all or part of the plurality of coils in parallel. 9. A vibration generator for supporting a coil and a permanent magnet so that they can move relative to each other and converting an external vibration into an induced voltage of the coil, wherein the permanent magnet and at least a part of a magnetic flux of the permanent magnet. Receiving coil, an inductance varying means for changing the inductance of the coil, a detecting section for detecting the amplitude of relative motion of the permanent magnet and the coil, and a control for changing the inductance of the coil based on the output of the detecting section. And a vibration generator. 10. The control unit controls the inductance of the coil such that the permanent magnet and the coil move relative to each other within a maximum movable range.
Vibration generator as described. 11. The control unit increases the inductance of the coil when the amplitude of the relative movement is larger than a first predetermined value, and the amplitude of the relative movement is a second predetermined value. 10. The vibration power generator according to claim 9, wherein the inductance of the coil is reduced when smaller than, and the first value is larger than the second value.