JPH06325976A - Capacitor - Google Patents

Abstract

PURPOSE:To one element both with functions as capacitor element and with those as inductor element, thereby make it possible to reduce the number of circuit elements in applications where both capacitor and inductor elements are used, and thus miniatutize the device. CONSTITUTION:Electrode films (A-B and A'-B'), opposite to each other, are placed on both sides of a dielectric film (C) to produce capacitance between terminals. These films (A-B, A'-B' and C) are rolled to provide the electrode films (A-A and A'-B') with inductance characteristics. This provides one element both with capacitance characteristics and with inductance characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor as a circuit element, and more particularly to a capacitor having both characteristics as a capacitive element and characteristics as an inductive element.

[0002]

2. Description of the Related Art In conventional capacitor elements, there is a technical interest in reducing the amount of inductance components that are parasitically generated when an electrostatic capacitance is realized. There has been a technical interest in how to reduce the capacity generated in the.

However, there are many examples in which a capacitor element and an inductance element are used in combination for a specific application. In this case, it is usual to prepare a capacitor element and an inductance element separately to configure a circuit.

[0004]

As described above, conventionally, even in a specific application where a capacitor element and an inductance element are used in combination, the capacitor element and the inductance element are separately prepared to form a circuit. The number of circuit elements has increased, the circuit configuration has become complicated and large, the time and effort required to create the circuit have been increased, and the reliability may have deteriorated due to the large number of elements.

Therefore, the present invention solves such a problem and realizes an element having both an inductance characteristic and a capacitance characteristic for such a specific application, reducing the number of circuit elements and drastically reducing the apparatus. The aim is to achieve a more compact design.

[0006]

SUMMARY OF THE INVENTION In a capacitor formed by alternately laminating electrode films which are insulated and opposed to each other with a film-shaped dielectric material sandwiched therebetween, and winding up a terminal lead-out portion of each electrode film, At the end of winding or at two intermediate points of the electrode film, each electrode film sees from the terminals on the winding start side and the winding end side of each electrode film, and each electrode film itself or through the internal capacitance. The thing is arranged so as to function as an inductance.

[0007]

In the present invention, a single element is realized in this way so as to have both the inductance characteristic and the capacitance characteristic. Therefore, for a specific application, the number of circuit elements can be reduced, and the apparatus can be greatly reduced in size. Can be planned.

[0008]

Embodiments of the capacitor according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a capacitor element according to the present invention.

This element has a four-terminal structure, and the terminals A or B and the terminals A'or B'are formed by the electrode films AB and A'-B 'sandwiching the dielectric film C and facing each other.
It has a capacitance between and. Further, by winding each of the films as shown in the figure, the terminal A-
Inductance characteristics are produced between B and between terminals A ′ and B ′.

A schematic development view of this element is shown in FIG.
When the power source E is connected between the terminals A and B'in this element, a charging current flows so as to charge the electrostatic capacitance. The direction of this charging current flows from the center to the periphery of the winding structure of the roll-in molded body in FIG. 1, but at this time the main current flows spirally in the electrode film. When the characteristic of this element is shown in a circuit diagram, as shown in FIG. 3A, it is in a state of being electrostatically coupled by the capacitances existing between the inductance AB and the inductances A′-B ′, which is equivalent. Specifically, it is represented by a series circuit of an inductance and a capacitance as shown in FIG.

In the above description, a dielectric film is used as an insulator, but thin paper is used as a separator and is impregnated with an electrolytic solution, or an oxide electrolyte such as MnO ₂ is used as an insulator for electrodes. By treating and using the film surface, the dielectric constant can be increased and the capacitance can be increased.

FIG. 4 shows another embodiment of the capacitor element according to the present invention.

In order to secure the facing area of the electrode film that determines the capacitance, when the winding length is determined, the number of turns required as an inductance and the winding length may not match. In such a case, the mounting span of the extraction electrode is adjusted to adjust the inductance. Between terminals AB and terminal A '
Since the inductance characteristic is adjusted between −B ′, different inductances can be obtained with the same capacitance.

FIG. 5 shows the structure of a transformer according to an embodiment of the present invention.

FIG. 5 (a) is an outline drawing thereof, and FIG.
(B) is the equivalent circuit diagram. The transformer is composed of an annular magnetic core, an exciting coil L and a capacitor according to the present invention. As shown in the circuit diagram of FIG. 6, the switch Sw1 and the power source E are connected to the primary side of this transformer, and the diodes D1 to D5, the switch Sw2 and the load Ll are connected to the secondary side of the transformer to form a drive circuit for the load Ll. Constitute. The operation of this circuit will be described below.

When the switch Sw1 connected to the power source E is closed, a current flows in the exciting coil L and increases, and magnetic energy is accumulated in the magnetic core.

When the switch Sw1 is opened at an arbitrary timing, the element according to the present invention corresponding to the secondary side is
An induced magnetomotive force that makes A and A ′ negative and B and B ′ positive is generated. Due to this magnetomotive force, from the terminal B ′ to the terminal A via the diode D1 and further to the terminal B via the interwinding capacitance Cs.
A charging current for the inter-winding capacitance Cs that returns to ′ flows. As a result, the inter-winding capacitance Cs is charged and the A-B electrode is positively set to A
Charge is accumulated by making the'-B 'electrode negative.

By repeating the process of opening and closing the switch Sw1, the terminal voltage of the interwinding capacitance Cs rises and becomes higher than the power supply voltage.

The switch Sw2 is a switch means for opening and closing the load Ll. By closing the switch Sw2, the charge accumulated in the interwinding capacitance Cs can be applied to the load Ll through the diodes D2 to D5.

At this time, the current flowing through the load is coil A-B.
Since the winding start and the winding end of A′-B ′ respectively flow in equilibrium, this element does not exhibit an inductance characteristic with respect to this load current.

By doing so, a high driving voltage can be obtained even from a low voltage power source, and there is an advantage that a good rise of the load current can be ensured for an inductive load, for example. Moreover, it can be made smaller and lighter as the number of elements is smaller.

The capacitance of this element is determined by the area of the electrodes facing each other, the spacing between the electrodes, the dielectric constant of the dielectric material, and the inductance is determined by the magnetic permeability of the magnetic core used and the number of windings of the film.

In order to adjust the values of these electrostatic capacitance and inductance to desired values, there is a method of using a plurality of electrode films connected in parallel as shown in FIG. Figure 7
In (b), A1 to A3 are collectively referred to as an A electrode, and A'1 to A3
An example is shown in which A′3 is collectively used as an A ′ electrode. Similarly, a plurality of electrode films are connected in parallel and used for the B electrode and the B ′ electrode. FIG. 7C is an explanatory diagram of this connection. This makes it possible to adjust the capacity and the inductance as well as the current capacity.

[0025]

As described above, according to the present invention, the electrode films facing each other with the insulating film interposed therebetween have a capacitance between the electrode films, and by winding each film, the inductance can be improved. Since the characteristics are created in the electrode film, with one element,
It is possible to combine the performances of the capacitor element and the inductor element, and when the capacitor element and the inductor element are used at the same time, the number of circuit elements can be reduced and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing an appearance and a configuration of an embodiment of a capacitor of the present invention.

FIG. 2 is a diagram schematically showing development of an embodiment of a capacitor of the present invention.

FIG. 3 is an equivalent circuit diagram of an example of a capacitor of the present invention.

FIG. 4 is a diagram showing development of another embodiment of the capacitor of the present invention.

FIG. 5 is an external view of a transformer using the capacitor of the present invention and its equivalent circuit diagram.

6 is a circuit diagram of an embodiment in which the transformer shown in FIG. 4 is used in a load driving device.

FIG. 7 is an explanatory diagram of a method of adjusting the capacitance and the inductance of the capacitor of the present invention.

[Explanation of symbols]

 A, B, A ′, B ′ Electrode film terminal C Dielectric film Cs Inter-winding capacitance D1 to D5 Diode E Power supply L Transformer winding Ll Load

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichiro Maeda 2597 Shinomiya, Hiratsuka City, Kanagawa Prefecture Komatsu Ltd. Electronics Business Headquarters (72) Inventor Daisuke Yoshida 2597 Shinomiya, Hiratsuka City, Kanagawa Electronics Division, Komatsu Ltd.

Claims (4)

[Claims] 1. A capacitor formed by alternately laminating electrode films which are insulated and opposed to each other with a film-shaped dielectric material sandwiched therebetween and wound the terminal lead-out parts of the respective electrode films at the start and end of winding of the roll-formed body. , Or at two intermediate points of the electrode film, each electrode film itself or through an internal capacitance when viewed from the winding start side and winding end side terminals of each electrode film. However, a capacitor that also functions as an inductance. 2. The capacitor according to claim 1, wherein a magnetic core is provided inside the winding molded body in order to enhance the effect as an inductance. 3. The capacitor according to claim 1, wherein an electrolyte is provided between the electrode films instead of the film-shaped dielectric material to insulate the surface of the electrode. 4. The capacitor according to claim 1, 2 or 3, wherein a plurality of said insulating and opposing electrode films are connected in parallel.