JPH09257961A - Power generator and portable device equipped with the same - Google Patents

Abstract

(57) [Abstract] [Problem] Like a power generator housed in a portable device,
Provided is a power generation device that converts a given kinetic energy into electric energy, and can exhibit sufficient charging efficiency even when the electromotive force obtained by the kinetic energy is low. A power storage unit 30 is provided in series with a power generation unit 10,
Electric power is temporarily stored in this power storage unit 30 using a unidirectional element 35 in the opposite direction to the rectification unit 20 that performs half-wave rectification. As a result, the power supplied from the rectification unit 20 to the supply unit 4 can be increased, so that even if the electromotive force of the power generation unit 10 is small with respect to the supply unit 4, the power supplied from the power generation unit 10 supplies power. The part 4 can be charged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation device for generating power using kinetic energy obtained from a weight of a rotary weight and the like, and a portable device using the power generation device.

[0002]

2. Description of the Related Art In a small and portable electronic device such as a wristwatch device, a portable device which does not require replacement of a battery by incorporating a power generator or a battery itself has been devised and put into practical use. Has been done. As an example thereof, FIG. 6 shows a schematic configuration of a wristwatch device having the power generator 10 built therein. In this portable device, a rotary weight 11 that performs a turning motion in the case of the wristwatch device, and a rotary weight 1
1. A train wheel mechanism 1 for transmitting the rotational movement of No. 1 to the power generation rotor 13
2 and the power generation unit 10. The power generation unit 10 includes a power generation rotor 13 having permanent magnets and stators 14 located on both sides of the rotor 13, and the power generation rotor 1
When 3 rotates, an electromotive force is generated in the power generation coil 15 of the stator 14, and an AC output can be taken out.
The alternating current output from the power generation unit 10 is rectified by the rectification circuit 20 and stored in the supply unit 4 configured by the capacitor 5 and the like. Then, electric power is supplied from the supply unit 4 to the processing device 6 such as the timing device 7 so that the processing device 6 can operate.

FIG. 7 shows a partial cross section of the above wristwatch device. Each element constituting the power generation unit 10 is supported so as to be sandwiched by the main plate 17 and the rotary weight bridge 17a of the wristwatch device. The oscillating weight 11 is rotatably supported by a ball bearing 18 with respect to the oscillating weight receiver 17a, and the rotational movement of the oscillating weight 11 includes wheels such as the oscillating weight wheel 11a, a transmission wheel pinion 12a, a transmission wheel 12b, and a transmission wheel gear 12c. It is transmitted to the rotor 13 for power generation by the row mechanism 12. Then, as the magnet 13a of the power-generating rotor 13 rotates in the power-generating stator 14, the kinetic energy of the rotary weight 11 is converted into electrical energy and output as AC power. A portable device equipped with such a power generator captures movements of a user's arm and converts it into kinetic energy of a rotary weight, and further converts the kinetic energy into electric energy to process a time measuring device. The device can be operated. Therefore, battery replacement is not required, and the functions of the portable device can be used anytime and anywhere.

[0004]

A power generator, which is housed in a portable device and converts kinetic energy of a rotary weight or the like into electric energy to generate electricity, uses kinetic energy obtained by the movement of a user's arm or the like. Since it is used to generate power, it is difficult to obtain a constant power generation output continuously. Therefore, the power output from the power generation unit is stored using a power supply unit such as a capacitor or a secondary battery, and it is important to efficiently charge the power output from the power generation unit to this power supply unit. . In particular, when a certain amount of electric power is stored in the supply unit, the supply unit cannot be charged unless an electromotive force higher than the voltage of the supply unit is obtained from the power generation unit. The electromotive force of the power generation unit changes depending on the density of kinetic energy supplied. For example, in a power generator using a rotary weight, a user's movement is required to increase the rotation speed of the rotary weight to increase the rotation speed of the power generation rotor. on the other hand,
Even if the user loosely moves, the rotor for power generation will rotate at a sufficiently high speed and high electromotive force will be obtained.
Since it is necessary to accelerate the movement of the rotary weight and transmit it to the power generation unit, the train wheel mechanism becomes complicated and large. Further, since the rotation speed of the rotor becomes extremely high, problems such as vibrations and supporting methods associated therewith also occur. Furthermore, there is a problem that mechanical loss increases by increasing the rotation speed.

Therefore, in the present invention, by realizing a power generator which can obtain a sufficiently high electromotive force by a user's loose operation without increasing the rotation speed of the rotor, the power generator can efficiently charge the supply section. Is intended to provide. Furthermore, it is an object of the present invention to provide a power generator having a high power generation capacity, which can be housed in a small portable device with a simple structure. Then, it is an object of the present invention to provide a portable device capable of fully exhibiting the function of the processing device housed in the portable device at any time and anywhere by using this power generation device.

[0006]

Therefore, in the present invention, the rectifying unit half-wave rectifies the AC output output from the power generation unit, and the rectified output has an opposite polarity to the power generation unit in series. The potential of the AC output that is half-wave rectified is raised by temporarily storing in the connected power storage unit. That is, the power generator of the present invention converts a kinetic energy into an electrical energy and outputs an alternating current, a rectifying part for half-wave rectifying an alternating current output from the power generating part, and stores rectified power to the outside. A power supply unit having a supply unit for supplying, and further connected to the power generation unit in series;
It is characterized by having a unidirectional element capable of charging the power storage unit by supplying an alternating current output having a polarity opposite to that of the rectification unit. Therefore,
For example, if a power generation mechanism that uses a rotor and a stator is used in the power generation unit, the output voltage from the power generation unit can be increased without increasing the rotation speed of the rotor, so it is necessary to newly install a mechanism for speeding up. In addition, even if the density of kinetic energy supplied to the power generation unit is low, the power can be efficiently generated and the supply unit can be charged. Further, even when the vibrating piece using the piezoelectric element is used to configure the power generation unit, it is not necessary to increase the amplitude of the vibrating piece, so that increase in mechanical loss is prevented, power generation efficiency and charging are improved. The efficiency can be improved.

Further, by selecting the capacitance component of the power storage unit so that the resonance frequency of the power generation unit and the power storage unit substantially matches the frequency of the AC output output from the power generation unit, the impedance of the power generation unit and the power storage unit is minimized. You can Therefore, it is possible to utilize the power generation capacity of the power generation unit to supply a large current to the supply unit and further improve the power generation efficiency and the charging efficiency.

When the power generation section uses the kinetic energy of the weight to generate power, the output AC frequency is not necessarily constant, so the AC with a high probability that the resonance frequency of the power generation section and the power storage section is output from the power generation section. It is desirable to select the capacitance component of the power storage unit so as to approximately match the output frequency. When the power generator is a wrist-worn device and a rotary type having a rotor and a stator is used as the power generator, the resonance frequency is set in the range of 10 Hz to 2 kHz in consideration of the movement of the user's arm. It is desirable to do.
Considering the inductance of the stator coil of this rotary power generation unit, the capacitance component of the power storage unit is 0.01 μF.
To 10 μF is desirable.

Further, if the power storage unit is connected in series with the power generation unit and the voltage supplied to the supply unit is boosted, a voltage higher than the allowable voltage of the supply unit or the processing unit connected thereto may be applied. . Therefore, it is desirable to provide a bypass means for short-circuiting the AC output when the voltage value of the AC output reaches a predetermined value. When the bypass means is a transistor switch, a parasitic diode of the transistor switch may be used as the unidirectional element to further simplify the power generation device. It is also possible to connect a Schottky barrier diode as a unidirectional element in parallel to the bypass means to reduce the voltage drop when the power storage unit is temporarily charged and improve power generation and charging efficiency. .

In a portable device equipped with such a power generator and a processing device operable by the power from the power generator, sufficient power can be obtained anytime and anywhere by the movement of the user. The function of the processing device can be fully exerted without worrying about battery replacement.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In order to explain the present invention in more detail, some embodiments of the present invention will be shown below with reference to the drawings. FIG. 1 shows a power generator 1 according to an embodiment of the present invention.
The configuration is shown using a circuit diagram. Power generation device 1 of this example
Includes a power generation unit 10 that outputs alternating current, a rectification unit 20 that half-wave rectifies the alternating current output, and a supply unit 4 that stores the rectified power and supplies the rectified power from a supply end 2 to a processing device (not illustrated). There is. Furthermore, a power storage unit 30 including a capacitor 31 is connected in series to the power generation unit 10, and a unidirectional element 35 using a diode 36 is connected in parallel with the power generation unit 10 and the power storage unit 30. This unidirectional element 35
Has a polarity opposite to that of the rectifying unit 20. further,
A bypass unit 40 using a MOS transistor 41 is connected in parallel with the power generation unit 10 and the power storage unit 30 so as to short-circuit outputs from the power generation unit 10 and the power storage unit 30, and the MOS transistor 41 is controlled by a control circuit 42. It is adapted to be turned on and off based on the output voltage from 30.

The power generation section 10 of this embodiment outputs AC power such as a rotary power generation mechanism having the rotor and the stator as described above or a vibration type power generation mechanism having a vibrator using a piezoelectric material. Therefore, the electric power w1 having a polarity half-wave rectified and the electric power w2 having an opposite polarity are generated from the power generation unit 10.
Is output. Electric power w2 flows through power storage unit 30 and unidirectional element 35 to charge power storage unit 30. on the other hand,
The power w1 is rectified through the rectification unit 20 and supplied to the supply unit 4. At that time, the power storage unit 30 charged by the power w2 is connected to the power generation unit 10 in series, so The voltage Vo of the electric power supplied to the supply unit 4 through the unit 20 is the output voltage Vg of the power generation unit 10 plus the voltage Vc generated by the charge temporarily stored in the power storage unit 30.

FIG. 2 shows changes in the supply voltage Vo when boost rectification is performed using the power storage unit 20 of the present example and when half-wave rectification is performed without conventional boost rectification. The supply unit 4 is not charged unless the supply voltage Vo of the rectified electric power exceeds the voltage Vs of the supply unit 4. Therefore,
When the supply unit 4 has the voltage Vs0, the supply unit 4 is charged by the shaded portion in FIG. 2 among the supplied power.
In the power generation device 1 of the present example, since the supply voltage Vo is boosted using the power storage unit 20, the supply voltage Vo should be increased even when the same voltage Vg output is obtained from the power generation unit 10. The charging efficiency for the supply unit 4 can be improved. In particular, when the supply unit 4 is charged to some extent and its voltage reaches Vs1, almost no charging can be performed in the power generation device that is not boosted, whereas sufficient charging can be performed in the power generation device 1 of this example.

FIG. 3 shows, in a solid line, the tendency of the charging efficiency of the power generation device of the present invention which has been boosted and rectified to vary with the voltage Vs of the supply unit. In addition, the trend of changing charging efficiency when half-wave rectification is performed without using the power storage unit is shown by a chain line. FIG. 3A shows a tendency when the electromotive force of the power generation unit 10 is high, for example, when the portable device worn on the arm is moved abruptly. As can be seen from the figure, when the voltage Vs of the supply unit 4 is low, the power storage unit 3
Since there is no loss in 0 and the unidirectional element 35, the device that has performed half-wave rectification has higher charging efficiency. In contrast,
When the voltage Vs of the supply unit 4 rises, a sufficient supply voltage Vo
Therefore, the charging efficiency is higher in the power generation device of the present example in which boost rectification is performed. FIG. 3B shows the power generation unit 10
Shows the tendency of the charging efficiency when the electromotive force is low, and as can be seen from this figure, the power generation device of this example in which the boosted rectification is performed to raise the supply voltage Vo can secure higher charging efficiency.

In a portable device, it is not always possible to receive power supply from the power generation unit 10, so it is important to fully charge the supply unit 4. The power generation device of the present invention uses the power storage unit 30 to perform boost rectification.
However, a sufficiently high supply voltage Vo can be secured to the supply unit 4 regardless of the state of power generation. Therefore, whether the movement of the arm is gentle or fast, the supply unit 4
The charging efficiency in the region where the voltage Vs is high can be significantly improved, and the supply unit 4 can be fully charged in a short time. For this reason,
Sufficient electric power can be supplied to the processing device connected to the power generation device of this example for a long time. In addition, even if the movement of the arm is gentle and the density of the kinetic energy obtained as a weight exercise is low, high charging efficiency can be obtained, so even if the user does not move the arm violently, it is sufficient for daily activities. Power can be obtained. Therefore, even a user who does not move a lot can fully exhibit the function of the portable device including the power generation device of the present invention regardless of age or sex.

Further, in the power generator 1 of this example, the control circuit 42 of the bypass unit 40 monitors the voltage Vo applied to the supply unit 4, and the boosted voltage is supplied to the supply unit 4 or the processing device connected thereto. If there is an adverse effect, switch 41
Thus, the AC output from the power generation unit 10 can be short-circuited. Therefore, the electromotive force of the power generation unit 10 increases,
If the processing device or the like fails when the voltage is boosted and rectified, the power supply is cut off, so that the function of the processing device can be used safely and reliably. Control circuit 4
For 2, various known circuits that compare the supply voltage Vo with a reference voltage by a comparator or the like can be adopted.

As described above, by connecting the power storage unit 30 to the power generation unit 10 in series and temporarily storing the power from the power generation unit 10 using the unidirectional element, the voltage of the supply unit 4 is particularly high. In this case, power generation efficiency and charging efficiency can be improved. Further, in the present invention, as shown in FIG. 4, the power generation unit 10 is focused on the components of the inductance (L) and the resistance (R) of the power generation coil, and is configured by these and the capacitance component C of the power storage unit 30. By appropriately setting the resonance frequency of the resonance circuit, the power generation and charging efficiency of the power generation device 1 is improved. In particular, by analyzing the power generation device 1 as a resonance circuit, the loss in the power storage unit 30 can be reduced, so that the charging efficiency when the voltage Vs of the supply unit 4 is low and the electromotive force of the power generation unit 10 is large illustrated in FIG. It is possible to improve. Of the AC output output from the power generation unit 10, for the current w1 that is charged in the supply unit 4 through the rectifying unit 20, the supply unit 4
Capacity of the supply circuit 4 is set to be much larger than the capacity of the power storage section 30.
It is not considered below.

The impedance (Z) of the power generation device can be approximately expressed by setting the inductance component of the power generation unit 10 to L, the resistance component to R, and the capacitance component of the capacitor 31 of the power storage unit 30 to C. Z is represented by the following formula.

Z = √ (R ² + (2πfL−1 / (2πfC)) ² ) ... (1) where f is the frequency of the alternating current output from the power generation unit 10, and is a two-pole rotary type. This corresponds to the rotation speed of the rotor in the power generation unit 10. Then, when f is represented by the following formula, the resonance frequency becomes f0 and the impedance Z becomes the minimum, so that a large current flows through the circuit.

F0 = 1 / (2π√ (LC)) (2) Therefore, in an environment where a power generator such as a wrist-worn type is installed, the frequency with the highest probability obtained from the power generator is expressed by the formula (2) The output supplied to the supply unit 4 can be increased by setting the capacitance component C of the power storage unit 30 to have the resonance frequency shown in ().

In an arm-mounted power generator that converts a user's movement into kinetic energy using the rotary weight as shown in FIG. 6, the movement of the rotary weight is accelerated by about 100 times and applied to the rotor. Therefore, when the hand is vigorously moved using the 2-pole rotary power generation unit 10, a high AC output with a frequency of 1 to 2 kHz is obtained. On the other hand, in the rotary power generation unit, almost no output is obtained at a rotation of about several Hz. Therefore, it is desirable to set the capacitance component C of the power storage unit 30 so that the AC output of 10 Hz to 2 kHz becomes the resonance frequency of the power generator. In particular, in order to improve the charging efficiency when the electromotive force of the power generation unit 10 is large as shown in FIG. 3, when the rotation speed of the rotor of the power generation unit 10 is high, that is, in the region where the frequency of the AC output is high. Resonance frequency f0
Is preferably set, and it is effective to set the resonance frequency to about 200 Hz or higher.

In addition, the inductance L of the power generating coil of the stator is usually in the range of 0.1 to 1.0 (H). Therefore, the capacitance component C of the electricity storage unit 30 has an inductance L of 0.1 to 1.0 and a resonance frequency f0 of 10 to 2000 Hz, corresponding to 1.0 × 10 ^−8.
It is desirable to be set to ˜1.0 × 10 ⁻⁵ (F) (0.01 μF to 10 μF). Therefore, as the power storage unit 30,
A capacitor or the gate capacitance of a MOS transistor can be used.

Further, in the power generator 1 shown in FIG. 4, the bypass switch 41 of the bypass unit 40 is used as the MO switch.
The S transistor 41 is adopted, and the parasitic diode 43 constitutes the unidirectional element 35. Therefore, the power generation device 1 becomes more compact and can be made smaller.

Further, FIG. 5 shows a MOS transistor 41.
And a Schottky barrier diode 37 are connected in parallel to form a unidirectional element 35. Therefore, the Schottky barrier diode 37 and the parasitic diode 43 of the MOS transistor 41 are connected in parallel, and the voltage drop in the unidirectional element 35 can be reduced. Therefore, the power storage unit 30 is connected via the unidirectional element 35.
The voltage drop during temporary charging becomes small, and the charging efficiency can be particularly improved when the electromotive force of the power generation unit shown in FIG. 3 is large. Therefore, the power generation device 1 of this example includes the power storage unit 3
Since a value suitable for the resonance frequency of the power generator is set as the capacity of 0 and the voltage drop in the unidirectional element 35 is reduced, the charging efficiency is high even when the electromotive force of the power generation unit changes, and It is a power generation device that can effectively utilize electric energy converted from energy.

Further, since it is not necessary to increase the rotation speed of the rotor in order to increase the supply voltage Vo, mechanical change such as complicating the train wheel mechanism is unnecessary, and the power generation is small and highly efficient for carrying. A device can be provided. Further, since it is possible to prevent an increase in mechanical loss and modification of the power generation unit due to increasing the number of rotors, it is possible to realize an inexpensive and highly efficient power generation device.

In the above-described example, the rotary type power generating unit including the rotor and the stator is described. However, the kinetic energy of the vibrating type using the vibrating reed including the piezoelectric layer is exchanged. Needless to say, it may be a power generation unit that can be converted into an output. Resonance frequency f0 and power storage unit 3
The capacity C of 0 may be set based on the frequency of the AC frequency generated in each power generation unit. Further, the unidirectional element is not limited to the Schottky barrier diode, and the same effect can be obtained even if it is a silicon diode or the like.

Further, the power generator is not limited to the wrist-worn type, and various forms such as a device mounted on a user's leg or mounted on a vehicle to generate power by vibration thereof are possible. .

Further, the processing device which is supplied with electric power from the power generation device of the present invention and performs the processing is not limited to the above-mentioned timing device, and for example, a pager, a telephone, a wireless device, a hearing aid, a pedometer, a calculator, an electronic notebook, etc. Information terminals, IC cards, radio receivers, etc., and by applying the power generation device of the present invention to these portable devices, it is possible to supply sufficient power to these processing devices. And
By adopting the power generation device of the present invention in these portable electronic devices, it is possible to efficiently generate power by capturing human movements and the like, and suppress battery consumption or eliminate the need for the battery itself. It is possible. Therefore, the user can use these portable devices without worrying about running out of battery, and it is possible to prevent troubles such as loss of contents stored in the memory due to running out of battery. Further, the function of the portable device can be exerted even in a situation where it is difficult to replenish the battery due to an area or place where the battery or the charging device is not easily available, or a disaster or the like.

[0029]

As described above, in the power generator of the present invention, the power storage unit is connected in series to the power storage unit, and the power storage unit temporarily stores a current having a polarity opposite to the direction of half-wave rectification. As a result, the voltage supplied to the supply unit can be increased. Therefore, the supply power supplied from the rectification unit to the supply unit can be increased, so that the supply unit can be charged with the electric power output from the power generation unit even when the electromotive force of the power generation unit is small with respect to the supply unit. As described above, even when the output voltage of the power generation unit is low, it is possible to charge the power supply unit with the power, and high charging is possible even in a power generation device such as a portable device in which the output power fluctuates. You can get efficiency.

Further, since a high supply voltage can be obtained without increasing the rotation speed of the rotor of the power generation section, a highly efficient power generation device suitable for small size and portable can be realized. Then, by using this power generation device, it is possible to provide a portable device capable of fully exhibiting the function of the processing device housed in the portable device anytime, anywhere.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a power generator according to an embodiment of the present invention.

FIG. 2 is a diagram showing a supply voltage that is boosted and rectified by the power generation device shown in FIG. 1 and supplied to a supply unit in comparison with a supply voltage that is half-wave rectified, and FIG. 2B shows the state in which the voltage is boosted and rectified.

FIG. 3 is a diagram showing how the charging efficiency in the case of step-up rectification and the charging efficiency in the case of half-wave rectification change depending on the voltage Vs of the supply unit, and FIG. A high case is shown, and FIG. 3B shows a case where the electromotive force of the power generation unit is low.

FIG. 4 is a circuit diagram showing a different embodiment of the present invention.

FIG. 5 is a circuit diagram showing still another embodiment of the present invention.

FIG. 6 is a diagram showing a configuration example of a portable device capable of converting rotational energy of a rotary weight into electric energy.

FIG. 7 is a diagram showing a cross section of a configuration in the case where the portable device shown in FIG. 6 is realized as an arm mounting type.

[Explanation of symbols]

 1 .. Generator unit 4 .. Supply unit 10 .. Power generation unit 20 .. Rectifier unit 30 .. Storage unit 35 .. Unidirectional element 36 .. Diode 37 .. Schottky barrier diode 40 .. Bypass unit 41 .. Bypass switch 42 Control circuit 43 Parasitic diode R Resistance component of power generation unit L

Claims (9)

[Claims] 1. A power generation unit that converts kinetic energy into electric energy and outputs alternating current, a rectification unit that half-wave rectifies the AC output from the power generation unit, and a supply unit that stores the rectified power and supplies it to the outside. And further comprising a power storage unit connected in series with the power generation unit, and a unidirectional element capable of charging the power storage unit by causing the AC output having a polarity opposite to that of the rectification unit to flow. Generator. 2. The capacitance component of the power storage unit according to claim 1, wherein the resonance frequency of the power generation unit and the power storage unit is substantially equal to the frequency of the AC output output from the power generation unit. A power generator characterized in that. 3. The frequency of the AC output according to claim 1, wherein the power generation unit generates power using kinetic energy of a weight, and the resonance frequency of the power generation unit and the power storage unit has a high probability of being output from the power generation unit. The power generation device is characterized in that the capacitance component of the power storage unit is selected so as to substantially match with. 4. The power generator according to claim 3, wherein the power generator is a wrist-worn device, the power generator is a rotary type having a rotor and a stator, and the resonance frequency is 10 or less.
A power generation device having a frequency range of Hz to 2 kHz. 5. The power generator according to claim 3, wherein the power generator is a wrist-worn device, the power generator is a rotary type including a rotor and a stator, and the power storage unit has a capacitance component of 0.01 μF or less. A power generation device having a range of 10 μF. 6. The power generator according to claim 1, further comprising a bypass unit that short-circuits the AC output when the voltage value of the AC output reaches a predetermined value. 7. The power generator according to claim 6, wherein the bypass means is a transistor switch, and the unidirectional element is a parasitic diode of the transistor switch. 8. The power generator according to claim 6, wherein the unidirectional element is a diode connected in parallel to the bypass means. 9. A portable device comprising the power generator according to claim 1 and a processing device operable by the electric power from the power generator.