JP2010028896A - Power synthesizing circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power synthesizing circuit that synthesizes power from multiple electrostatic induction transformation devices through power drawing circuits respectively provided therein and can efficiently output even low voltage with low loss. <P>SOLUTION: The power synthesizing circuit includes multiple FETs 311. The drain of each of the FETs is connected to the output terminal 101c of a corresponding power drawing circuit 100 and the source and gate of each of the FETs are connected to a resultant power output terminal 301a. Each FET 311 is set on only when power is being output from the power drawing circuit 100 connected thereto. Accordingly, when any electrostatic induction transformation device 200 or power drawing circuit 300 becomes faulty, the relevant FET 311 is turned off. As a result, the faulty circuit is disconnected from the resultant power output terminal 301a and it does not impose load. Further, since voltage drop in each FET 311 is 0.1 V to 0.3 V or so, the power drawing efficiency is improved as compared with that in the prior art. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention synthesizes and outputs electric power extracted from a plurality of electrostatic induction conversion elements that convert kinetic energy generated by externally applied force due to vibration or the like into electric energy via electric power extraction circuits provided respectively. The present invention relates to a power combining circuit.

  In recent years, attention has been paid to the development of electric energy generation technology that does not pollute the environment, and solar power generation, wind power generation, and the like have been put into practical use. In such technical development, development of an electrostatic induction conversion element that converts kinetic energy generated by externally applied force such as vibration into electric energy is also underway as another electric energy generation technique.

  The electrostatic induction conversion element is disclosed in, for example, an electrostatic induction conversion element disclosed in Japanese Patent Application Laid-Open No. 2006-180450 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2007-31551 (Patent Document 2). An electrostatic induction conversion element is known.

  As shown in FIG. 9, the electrostatic induction conversion element 10 disclosed in Japanese Patent Application Laid-Open No. 2006-180450 (Patent Document 1) includes an electret 11 formed by injecting charges near the surface of an insulating material. Located between the two conductors 12 and 13 and arranged in electrical contact with one conductor 12, the other conductor 13 faces the electret 11 at a predetermined interval, and the conductor 13 and the electret 11. Are configured to relatively move and convert kinetic energy into electrical energy. As a result, when the two conductors 12 and 13 are electrically connected to the load 14 and the conductor 13 is reciprocated in the direction of the arrow in the figure, for example, the electric charge (negative charge in the figure) injected into the electret 11 A positive charge is electrostatically induced, and a current flows through the load 14. Therefore, the electrostatic induction conversion element 10 having the above configuration functions as a generator.

  The electrostatic induction conversion element disclosed in Japanese Patent Application Laid-Open No. 2007-31551 (Patent Document 2) has been improved so that the distance between the substrates can be properly maintained when the opposing substrates move relative to each other. It has been applied. That is, as shown in FIGS. 10 and 11, the two substrates 21 and 22 are arranged to face each other, and the electret 23 and the conductor 24 are formed on the opposing surfaces of the substrates 21 and 22. Yes. The substrates 21 and 22 move relative to each other in the direction parallel to the opposing surface (the directions of arrows A and B in the figure), and the electret 23 moves relative to the conductor 24 as the substrates 21 and 22 move relative to each other. The electromotive force is generated in the conductor 24 by electrostatic induction. In order to maintain the distance between the substrates 21 and 22 appropriately, the electret 23 and the conductor 24 are attracted by the electret 23 and the conductor 24 facing each other, and the repulsion generated by the electret 23 facing each other. It is arranged to balance the force.

  When taking out electric power from such an electrostatic induction type conversion element, for example, an electric power taking out circuit as shown in FIG. 12 has been used. In FIG. 12, reference numeral 30 denotes a power extraction circuit, which includes a pair of input terminals 31a and 31b, a pair of output terminals 31c and 31d, resistors 32, 33 and 34, and a diode 35.

  The input terminal 31 a is connected to the conductor 13, and the input terminal 31 b is connected to the conductor 12. One end of the resistor 32 is connected to the input terminal 31a, and the other end of the resistor 32 is connected to the input terminal 31b and the output terminal 31d via the resistor 33. The other end of the resistor 32 is connected to the anode of a diode 35. The cathode of the diode 35 is connected to the output terminal 31 c and is connected to the output terminal 31 d via the resistor 34.

  In the power extraction circuit 30, alternating current static electricity having a voltage of, for example, 80 V is generated between the electret 11 and the conductor 13 due to the reciprocating motion of the conductor 13, and current is applied to the resistors 32 and 33 connected in series. Flowing. The voltage generated between the electret 11 and the conductor 13 is divided by resistors 32 and 33 connected in series, and is rectified by a diode 35 after being set to a voltage of about 1 V to 5 V, for example. Since the resistance value between the electret 11 and the conductor 13 is several MΩ, the combined resistance values of the resistors 32 and 33 connected in series are set to substantially the same value.

Further, when combining the electric power extracted from the plurality of electrostatic induction conversion elements, the combined electric power is extracted by connecting the output terminals 31 c and 31 d of the plurality of electric power extraction circuits 30 in parallel. Further, in the case of synthesizing power by connecting in parallel as described above, when any of the electrostatic induction conversion element and the power extraction circuit 30 fails, the failed electrostatic induction conversion element and the power extraction circuit 30 It may become a load. In order to prevent this, a diode 41 is provided for each power extraction circuit 30 as shown in FIG. 13, the anode of the diode 41 is connected to the output terminal 31c of the power extraction circuit 30, and the cathode of the diode 41 is wired-connected. A power combining circuit 40 is used. Here, the output terminal 40 a of the power combining circuit 40 is connected to the cathode of the diode 41, and the output terminal 40 b of the power combining circuit 40 is connected to the output terminal 31 d of each power extraction circuit 30. By using such a power combining circuit 40, it is possible to efficiently extract electric power without using the failed electrostatic induction conversion element or the electric power extracting circuit 30 as a load.
JP 2006-180450 A JP 2007-31551 A

  However, when the power combining circuit 40 using the diodes 41 is used as described above, since the forward voltage of each diode 41 is 0.7 V in the case of a silicon diode, this voltage drop occurs and the power loss is large. Become. Furthermore, when the output voltage of the power extraction circuit 30 is 0.7 V or less, power cannot be extracted by the power combining circuit 40, and thus there is a problem that the power extraction efficiency is deteriorated.

  The present invention has been made in view of the above problems, and its object is to synthesize power extracted from a plurality of electrostatic induction conversion elements via power extraction circuits provided respectively, An object of the present invention is to provide a power combining circuit that can output efficiently to a low voltage with low loss.

  In order to achieve the above object, the present invention forms two substrates facing each other at a predetermined interval and capable of relative movement in a direction parallel to the facing surface, and at a predetermined position on the facing surface of at least one of the substrates. The electret, a conductor formed on the surface of the substrate facing the electret at a position facing the electret, and supporting the substrate so as to be capable of relative reciprocation in a predetermined linear direction parallel to the facing surface. An electrostatic induction conversion element that converts the kinetic energy of the relative motion generated in the two substrates by an external force to be converted into electric energy and outputs electric power from the electrostatic induction conversion element. Combines the power output from each of the plurality of power extraction circuits of a power supply unit comprising a plurality of power supply element modules each including a power extraction circuit A plurality of field effect transistors, each having an input terminal connected to an output terminal of the power extraction circuit and an output terminal connected to the combined power output terminal. And, for each field effect transistor, based on either the value of the voltage input to the field effect transistor from the power extraction circuit connected to the field effect transistor or the value of the voltage output from the field effect transistor. The present invention proposes a power combining circuit including control means for turning on the field effect transistor only when power is output from the power extraction circuit connected to the field effect transistor.

  The power combining circuit of the present invention includes a plurality of field effect transistors having an input terminal connected to the output terminal of the power extraction circuit and an output terminal connected to the combined power output terminal. Only when power is output from the power extraction circuit connected to the transistor, the transistor is turned on. For this reason, when any of the electrostatic induction conversion element or the power extraction circuit fails, no power is output from the power extraction circuit, so the field effect transistor is turned off. The circuit is disconnected from the combined power output terminal and these do not become a load. Furthermore, since the voltage drop in the field effect transistor is about 0.1 V to 0.3 V, the minimum voltage that can be taken out can be lowered as compared with the case where a conventional diode is used, and the power extraction efficiency is improved.

  According to the power combining circuit of the present invention, the failed electrostatic induction conversion element or power extraction circuit does not become a load, so that it is possible to efficiently extract power. Furthermore, since the voltage drop in the field effect transistor is a low voltage of about 0.1 V to 0.3 V, the minimum voltage that can be taken out can be lowered compared with the case of using a conventional diode, so that the power extraction efficiency is greatly improved. be able to.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 to 7 are diagrams showing an embodiment of the present invention, FIG. 1 is a block diagram showing an electric circuit of a power supply unit in the embodiment of the present invention, and FIG. 2 is a power extraction in the embodiment of the present invention. FIG. 3 is a transparent perspective view showing an electrostatic induction conversion element according to one embodiment of the present invention, and FIG. 4 is an exploded perspective view of a main part showing the electrostatic induction conversion element according to one embodiment of the present invention. 5 is a plan view showing an electrostatic induction conversion element according to one embodiment of the present invention, FIG. 6 is a sectional view taken along the line AA in FIG. 5, and FIG. 7 is a static diagram according to one embodiment of the present invention. It is a figure which shows the electric system circuit of an electric induction type conversion element.

  As shown in FIG. 1, the power supply unit according to the present embodiment includes a plurality of electrostatic induction conversion elements 200, a plurality of power extraction circuits 100 connected to the output side of each of the electrostatic induction conversion elements 200, The power combining circuit 300 is configured to combine and output the power output from the power extraction circuit 100.

  The power combining circuit 300 is composed of a plurality of N-channel field effect transistors (hereinafter referred to as FETs) 311 provided for each power extraction circuit 100. The drain of each FET 311 is connected to the output terminal 101c of the corresponding power extraction circuit 100, and the source of the FET 311 is connected to the combined power output terminal 301a. Furthermore, the gate of each FET 311 is connected to its own source or combined power output terminal 301a. The ground output terminal 101d of each power extraction circuit 100 is connected to the ground output terminal 301b of the power combining circuit 300.

  In this embodiment, the FET 311 is an enhancement type = normally off type FET, i.e., a FET that does not have a channel and does not flow a drain current when no gate voltage is applied. I use it.

  The N-channel FET is normally turned on when the gate terminal voltage is lower than the drain terminal voltage. Therefore, in the power combining circuit 300 configured as described above, the FET 311 has a gate voltage (source voltage) of 0.1 to 0 higher than the drain voltage when power is output from the power extraction circuit 100 connected to the FET 311. .3V is lower, the power is turned on, and the power output from the power extraction circuit 100 passes through the FET 311 and is combined with the power output from the other FET 311 to be combined with the power output from the combined power output terminal 301a (not shown). Is output. The voltage drop between the drain and the source in the FET is about 0.3V for the silicon FET, whereas the voltage of the compound FET such as gallium arsenide is as low as about 0.1V. It is preferable to use an FET.

  On the other hand, when either the electrostatic induction conversion element 200 or the power extraction circuit 100 fails and no power is output from the power extraction circuit 100, the drain voltage of the FET 311 connected to the power extraction circuit 100 is 0V. In addition, since the gate voltage (source voltage) of the FET 311 is the same as the gate voltage of the other FET 311, the FET 311 connected to the subsequent stage of the failed electrostatic induction conversion element 200 or the power extraction circuit 100 is turned off. Thus, the FET 311 disconnects the power extraction circuit 100 from the combined power output terminal 301a.

  Therefore, the FET 311 is set to the ON state only when power is output from the power extraction circuit 100 connected to the FET 311. For this reason, when any of the electrostatic induction conversion element 200 and the power extraction circuit 100 fails, power is not output from the power extraction circuit 100, so the FET 311 is turned off, and the failed electrostatic induction conversion element 200 or power The extraction circuit 100 is disconnected from the combined power output terminal 301a, and these do not become a load. Furthermore, since the voltage drop in the FET 311 is about 0.1 V to 0.3 V, the minimum voltage that can be taken out can be lowered as compared with the case where a conventional diode is used, so that the power taking out efficiency can be improved.

  Note that the configuration of the power combining circuit 300 is a specific example of the present invention, and the present invention is not limited to the above embodiment.

  Next, configurations of the electrostatic induction conversion element 200 and the power extraction circuit 100 in the present embodiment will be described. 2 to 8, reference numeral 100 denotes a power extraction circuit, and reference numeral 200 denotes an electrostatic induction conversion element.

  The power extraction circuit 100 includes a transformer 110, a rectifier circuit 120, capacitors 102 and 104, and a resistor 103. Note that the rectifier circuit 120 in this embodiment includes two diodes 121 and 122.

  One end of the primary winding 111 of the transformer 110 is connected to a conductor 221 of an electrostatic induction conversion element 200 described later via an input terminal 101a, and the other end of the primary winding 111 of the transformer 110 is statically connected via an input terminal 101b. It is connected to the electret 231 of the electric induction conversion element 200. One end of the secondary winding 112 of the transformer 110 is connected to the anode of the diode 121, and the cathode of the diode 121 is connected to the cathode of the diode 122, the resistor 103, one end of the capacitor 104, and the output terminal 101c. The other end of the secondary winding 112 of the transformer 110 is connected to the anode of the diode 122, the resistor 103, the other end of the capacitor 104, the output terminal 101d, and to the input terminal 101b via the capacitor 102.

  Capacitor 102 positions the reference potential of electrostatic induction conversion element 200 as the reference potential of power extraction circuit 100, and blocks direct current between primary winding 111 and secondary winding 112 of transformer 110.

  The electrostatic induction conversion element 200 includes a rectangular parallelepiped housing 210 having a square upper surface. The housing 210 includes a fixed substrate 220 and a movable substrate 230, and the movable substrate 230 has one side of the upper surface. Are supported by springs 251 and 252 so as to be able to reciprocate in a predetermined linear direction parallel to the base plate, and the stationary substrate 220 and the movable substrate 230 reciprocate relatively to generate power.

  The bottom surface of the fixed substrate 220 is fixed to the inner bottom surface of the casing 210, and a comb-shaped conductor 221 is formed on the upper surface (opposing surface) of the fixed substrate 220. The comb-shaped conductor 221 is formed so that the comb teeth are orthogonal to the movable direction of the movable substrate 230 (C1 direction in FIG. 3). Further, the conductor 221 is electrically connected to an external electrode 212 provided on the outer bottom surface of the casing 210 via a wiring.

  The movable substrate 230 is supported by the bearing balls 241 so that the bottom surface (opposing surface) faces the upper surface of the fixed substrate 220 in parallel with a predetermined interval. Further, a comb-shaped electret 231 and a conductor film 232 conductively connected to the electret 231 are formed on the bottom surface (opposing surface) of the movable substrate 230. The comb-shaped electret 231 is formed so that the comb teeth are orthogonal to the movable direction of the movable substrate 230 (C1 direction in FIG. 3).

  Further, a support member 241 extending in a direction orthogonal to the movable direction C1 is provided on the upper portion of the movable substrate 230, and the vertical pieces 431b at both ends of the support member 241 are fixed to two opposing sides of the movable substrate 230. Has been. The support member 241 is made of a conductor, and one vertical piece 431b is conductively connected to the conductor film 232.

  One end of each of the two springs 251 and 252 is connected to the center of the horizontal piece 431a of the support member 241. These springs 251 and 252 are arranged so that the expansion and contraction direction thereof coincides with the movable direction C1. Further, the other ends of the springs 251 and 252 are fixed to the inner surface of the casing 210. The support member 241 is electrically connected to a wiring 252a made of a conductor provided on the spring 252 and an external electrode 213 provided on the outer bottom surface of the housing 210 via the wiring. In this embodiment, the springs 251 and 252 are pantograph-shaped springs in which thin plate springs of plastic are arranged on each side of the rhombus. A coil spring or a torsion bar may be used as the springs 251 and 251.

  The electrostatic induction conversion element 200 having the above-described configuration is subjected to a force such as vibration from the outside, and when the movable substrate 230 reciprocates in the movable direction C1, the electric charge injected into the comb-shaped electret 231 (for example, negative) The positive charge is electrostatically induced in the comb-shaped conductor 221 of the fixed substrate 220 by the electric charge), and electric power can be taken out from the external electrodes 212 and 213. Therefore, the electrostatic induction conversion element 200 having the above configuration functions as a generator.

  In the power extraction circuit 100 configured as described above, an AC voltage generated between the electret 231 and the conductor 221 of the electrostatic induction conversion element 200 is applied to the primary winding 111 of the transformer 110, and the primary winding 111 AC current flows. This alternating current generates a magnetic field in the primary winding 111, and this magnetic field crosses the secondary winding 112. As a result, a current is generated in the secondary winding 112 by magnetic induction, and AC power having a voltage corresponding to the turn ratio with the primary winding 111 is generated at both ends of the secondary winding 112. The AC power generated in the secondary winding 112 of the transformer 110 is converted into DC power by the rectifier circuit 120 and output from the output terminals 101c and 101d.

  In order to extract electric power more efficiently from the electrostatic induction conversion element 200, the resonance frequency of the resonance circuit configured by the capacitance between the electret 231 and the conductor 221 and the reactance of the primary winding 111 of the transformer 110 is reduced. It is preferable that the value be equal to the value of the vibration frequency of the reciprocating motion of the movable substrate 230.

  Further, since the voltage value of the DC output voltage after rectification is unstable, the DC voltage is preferably stabilized by a charge circuit using a capacitor or the like.

  In addition, when the external force applied to the electrostatic induction conversion element 200 fluctuates, the voltage value output from the electrostatic induction conversion element 200 becomes too high and exceeds the withstand voltage of the transformer 110, which may destroy the transformer 110. As shown in FIG. 8, it is preferable to provide a shunt diode 105 in parallel with the primary winding 111 as shown in FIG. By providing the shunt diode 105 in this way, the shunt diode 105 becomes conductive when the voltage having a value higher than the withstand voltage value of the shunt diode 105 is output from the electrostatic induction conversion element 200, thereby protecting the transformer 110. .

  In the above embodiment, the shape of the conductor 221 and the shape of the electret 231 are comb-shaped, but the present invention is not limited to this.

The block diagram which shows the electric system circuit of the power supply unit in one Embodiment of this invention The circuit diagram which shows the electric power extraction circuit in one Embodiment of this invention 1 is a perspective view showing an electrostatic induction conversion element according to an embodiment of the present invention. The principal part disassembled perspective view which shows the electrostatic induction type conversion element in one Embodiment of this invention. The top view which shows the electrostatic induction type conversion element in one Embodiment of this invention AA arrow direction sectional view in FIG. The figure which shows the electric system circuit of the electrostatic induction type conversion element in one Embodiment of this invention The circuit diagram which shows the other example of the electric power extraction circuit in one Embodiment of this invention The figure which shows the electrostatic induction type conversion element of a prior art example The figure which shows the electrostatic induction type conversion element of a prior art example The figure which shows the electrostatic induction type conversion element of a prior art example Circuit diagram showing conventional power extraction circuit Circuit diagram showing conventional power extraction circuit

Explanation of symbols

  100 ... Power extraction circuit, 101a, 101b ... Input terminal, 101c, 101d ... Output terminal, 102 ... Capacitor, 103 ... Resistor, 104 ... Capacitor, 105 ... Shunt diode, 110 ... Transformer, 111 ... Primary winding, 112 ... Secondary winding, 120 ... rectifier circuit, 121,122 ... diode, 200 ... static induction conversion element, 210 ... housing, 211 ... bottom surface, 212,213 ... external electrode, 214 ... bearing ball, 220 ... fixed substrate, 221 ... conductor , 230 ... movable substrate, 231 ... electret, 232 ... conductor film, 241 ... support member, 251, 252 ... coil spring, 300 ... power combining circuit, 301a, 301b output terminal, 311 ... field effect transistor.

Claims (3)

Two substrates that face each other at a predetermined interval and are capable of relative movement in a direction parallel to the opposite surface, an electret formed at a predetermined position on the opposite surface of at least one substrate, and a substrate that faces the electret Force applied from the outside, having a conductor formed on the surface of the substrate at a position facing the electret, and a support means for supporting the substrate so as to be capable of relative reciprocation in a predetermined linear direction parallel to the facing surface. A power element module comprising: an electrostatic induction conversion element that converts the kinetic energy of relative motion generated on the two substrates into electric energy and outputs the electric energy; and a power extraction circuit that extracts electric power from the electrostatic induction conversion element. A power combining circuit that combines and outputs power output from each of the plurality of power extraction circuits of a plurality of power supply units,
A plurality of field effect transistors provided for each of the power extraction circuits, wherein an input terminal is connected to an output terminal of the power extraction circuit and an output terminal is connected to a combined power output terminal;
For each field effect transistor, based on either the value of the voltage input to the field effect transistor from the power extraction circuit connected to the field effect transistor or the value of the voltage output from the field effect transistor, A power combining circuit comprising: control means for turning on the field effect transistor only when power is output from the power extraction circuit connected to the field effect transistor. An N-channel field effect transistor is provided as the field effect transistor,
The power combining circuit according to claim 1, wherein the control unit includes a gate terminal of the N-channel field effect transistor connected to the combined power output terminal.   The power combining circuit according to claim 1, wherein the field effect transistor is made of a compound semiconductor.

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