JPS6254983A - Transducer - Google Patents

Abstract

PURPOSE:To convert between a current and a voltage by obtaining a voltage in response to a deformation from a pair of surfaces of the second beam, driving the second beam by a voltage applied to the pair of surfaces to deform the both beams, and obtaining a current in response to the deformation by an outer magnetic circuit. CONSTITUTION:When a current is converted to a voltage, an exciting current is supplied from terminals 8, 9, while when the voltage is reversely converted to the current, an electromotive force is generated between the terminals 8 and 9 due to the vibration of a magnetic material 1. When a magnetic flux phi generated by the current (i) supplied from a signal source S repels from the material 1 of a beam, the beam is deflected downward, and the voltage of the polarity in response to the direction of the deformation is generated between the terminals 5 and 6. The magnetic flux phi generated by the current (i) supplied from the signal source S is attracted to the material 1 of the beam, the beam is deflected upward, and the voltage of reverse polarity is generated between the terminals 5 and 6. This is repeated to obtain a voltage proportional to the current of the source S from the terminals 5, 6. Thus, a conversion between the current and the voltage can be readily performed to expect various applications.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a current to voltage or voltage to current duducer.

Summary of the invention) The present invention forms a beam using a magnetic material and a piezoelectric material in a 2FJ structure or a multilayer structure, and drives the magnetic material by applying a magnetic field from the outside by a permanent magnet or by passing a current through a coil. Vibration is applied to the piezoelectric material to generate voltage from the piezoelectric material, and conversely, a voltage is applied to the piezoelectric material to drive the piezoelectric material, and the vibration generates a current in an external magnetic circuit via the magnetic material. This is a current-to-voltage transducer.

Background Art) FIG. 7(a) is a block diagram showing an example of a conventional transducer that does not use piezoelectric material, and 21 and 22 are piezoelectric materials,
23, 24, 25 are electrodes formed by vapor deposition or conductive paint, and 28, 27 are terminals. Furthermore, there are several aspects depending on the combination of directions in which voltage is generated in the piezoelectric material, as shown in Figure 7. In the case of series specifications, the connections may be made so that the voltages generated when stress is applied in the same direction are in opposite directions. Note that in that case, the electrode (24) between both piezoelectric materials becomes unnecessary.

Therefore, if we choose the direction of the voltage generated as shown by the arrow in Figure 7 (a) (the direction of the voltage generated when compression is applied from the lateral direction), we can When the beam formed from the piezoelectric material 21, 22 is deformed so as to be convex upward, the upper side becomes tensile and the lower side becomes compressive, with the neutral axis as the boundary, and due to the polarization effect of the piezoelectric material 21, 22. , a voltage is generated with the polarity shown and terminal 26.2
A voltage signal is taken out between 7 and 7. On the other hand, when it is bent in the opposite direction as shown in (c), the polarity of the voltage generated at the terminals 26 and 27 is reversed.

Further, although the above operation is a case where mechanical deformation is converted into voltage, it is also possible to mechanically deform the beam by applying a signal voltage to the terminals 26 and 27.

The reason why the beam is formed by using a two-layer structure of piezoelectric material as shown in FIG. 7 is that the voltages generated inside the piezoelectric material cancel each other out in one layer, so that no voltage can be extracted. That is, although FIG. 8(a) shows the case where the beam is composed of one layer, (b).

If it is bent as shown in (c), voltages of opposite polarity will be generated internally with the neutral axis 4 as the boundary, so 1@pole 2
When viewed from both ends of 9.30, the voltages cancel each other out and cannot be taken out from terminals 31.32.

By the way, although the conventional transducer operates as described above, its conversion function is only between mechanical displacement and expansion voltage, and it lacks applicability as a device.

(Object of the Invention) The present invention has been proposed in view of the above points, and its object is to provide a transducer that enables mutual conversion of current and voltage using piezoelectric materials. There is a particular thing.

(Structure of the invention) Hereinafter, the present invention will be described in detail with reference to the drawings showing examples.

FIG. 1 is a configuration diagram showing an embodiment of the transducer of the present invention, in which (A) is an external perspective view and (B) is a sectional view taken in the longitudinal direction. To explain the configuration in the figure, numeral 1 is a magnetic material forming the first beam, and a ceramic magnet or a normal magnet can be used.

Further, 2 is a piezoelectric material that forms the second beam, and electrodes 3 and 4 are formed on both sides of the piezoelectric material by vapor deposition or conductive paint, and it is connected to the first beam made of magnetic material 1 via the electrode 3. The beam has a two-layer structure as a whole. Note that the electrodes 3 and 4 are for extracting the voltage generated across the piezoelectric material 2 to the terminals 5 and 6, or for applying a voltage to both ends of the piezoelectric material 2, so if the magnetic material 1 is conductive. If a magnetic material is used, the electrode 3 may be omitted and the terminal 5 may be directly connected to the magnetic material 1, as shown in FIG.

Returning to FIG. 1 and explaining the configuration, magnetic material 1° piezoelectric material 2. The beam composed of the electrodes 3 and 4 has one end fixed to the fixed wall 10, and has a so-called cantilevered structure. Note that the structure is not limited to a cantilevered structure, and a structure in which the outside image side is fixed to a fixed wall 10, 11 as shown in FIG. 3 may be adopted. - On the other hand, in Fig. 1, 7 is a coil, and when converting current to voltage, exciting current is supplied from terminals 8 and 9, and conversely, when converting voltage to current, magnetic material 1
An electromotive force is generated between terminals 8 and 9 due to the vibration.

4 shows the operation when the transducer of FIG. 1 is used for converting current to voltage, and a signal source S is connected to the terminals 8 and 9 of the coil 7. In operation, when the magnetic flux φ generated by the current i supplied from the signal source S is repelled by the magnetic material 1 of the beam, the beam is deflected downward as shown in (a), and the polarity changes depending on the direction of the deformation. voltage is generated at terminals 5 and 6. In addition, when the magnetic flux φ generated by the current i supplied from the signal source S attracts the magnetic material 1 of the beam, the beam is deflected upward as shown in (b), and the terminals 5 and 6 have polarity opposite to that described above. voltage is generated. By repeating these steps, a voltage proportional to the current of the signal source S is obtained from the terminals 5 and 6.

Although the piezoelectric material 2 is one layer in the present invention, the neutral axis is shifted from the center of the piezoelectric material 2 due to the presence of the magnetic material 1, so the voltages do not cancel each other out inside the piezoelectric material 2. A voltage corresponding to the deformation can be extracted.

In addition, when converting voltage to current, terminals 5 and 6
By applying a signal voltage to the piezoelectric material 2, the magnetic material 1 vibrates, and this vibration induces a current in the externally provided coil 7.

In this way, the transducer of the present invention can generate voltage by applying a magnetic field from outside without contacting the beam, especially when converting current to voltage. There are many possible applications. For example, if the transducer of the present invention is implanted within biological tissue and the generated voltage is applied to the nervous system, it will be possible to control stimulation of the nervous system without contacting it from the outside. It can be applied to the following fields. Furthermore, in the field of electronic components, by applying the present invention to movable contacts such as micro relays, it is possible to control the displacement of the contacts by applying current or voltage bias.

Next, FIG. 5 shows another embodiment of the present invention, in which magnetic material 1. Piezoelectric material 2. One end of the beam made up of electrodes 3, 4, etc. is not fixed, but a weight 12 is provided at one end, so that the beam is deformed when a magnetic field is applied from the outside. In other words, although there is no stable fixing method within the biological tissue, if the weight 12 side is difficult to move when a magnetic field is applied by providing a weight imbalance in this way, then a cantilevered structure is possible. The operation is almost the same.

Next, Fig. 6 was considered from a similar point of view, and half of the first beam is made of non-magnetic material 13, and half of the beam is made so that no force acts even when a magnetic field is applied. The whole thing is deformed. Note that it is also possible to obtain still another configuration by applying the same idea.

(Effects of the Invention) As described above, in the present invention, a beam is formed using a two-layer structure or a multi-layer structure of a magnetic material and a piezoelectric material,
A magnetic material is driven by a permanent magnet or by applying a magnetic field from the outside by passing a current through a coil to give vibration to the piezoelectric material, causing the piezoelectric material to generate a voltage, and conversely, applying a voltage to the piezoelectric material. The piezoelectric material is driven by the piezoelectric material, and the vibration generates a current in an external magnetic circuit via the magnetic material, so conversion between current and voltage can be easily performed, and a variety of applications can be expected.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a configuration diagram showing an embodiment of the transducer of the present invention, in which (A) is an external perspective view, (B) is a longitudinal cross-sectional view, and FIGS. FIG. 3 is a block diagram showing another embodiment, FIG. 4 is an explanatory diagram of the operation of the embodiment shown in FIG. 1, FIGS. 5 and 6 are block diagrams showing other embodiments, and FIGS. FIG. 8 is an explanatory diagram of a conventional transducer using a piezoelectric material. 1...Magnetic material, 2...Piezoelectric material, 3,
4... Electrode, 5, 6, 8, 9... Terminal, 7... Coil, 10.11... Fixed wall, 12...・Weight, 13...Nonmagnetic material, S
・・・・・・Signal source

Claims (1)

[Claims] A first beam formed of a magnetic material and a second beam formed of a piezoelectric material are joined to form a two-layer structure or a multilayer structure, and a magnetic field obtained by passing a current through a coil or a permanent magnet is obtained. By applying a magnetic field from the outside, the first beam is driven to deform both beams, a voltage corresponding to the deformation is obtained from the pair of surfaces of the second beam, and a voltage corresponding to the deformation is obtained from the pair of surfaces of the second beam. A transducer characterized in that the second beam is driven by a voltage applied to the second beam to deform both beams, and a current corresponding to the deformation is obtained from an external magnetic circuit.