JPS6032759Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvements in electrolytic capacitors used in audio equipment and the like.

In recent years, electronic components such as capacitors used in audio systems have generally been designed with an emphasis on electrical characteristics, but as audio technology develops, not only electrical characteristics but also sound quality evaluation in audio systems has become important. It is well known that emphasis has been placed on

Especially when it comes to electrolytic capacitors, the sound quality of audio equipment is greatly affected by differences in components, structure, etc.
It is an electronic component with a lot of room for improvement.

In a conventional electrolytic capacitor, as shown in Fig. 1, an external lead terminal 1 is connected to an anode foil and a cathode foil by crimping or the like, and then the capacitor element 2 is formed by winding the terminals with electrolytic paper interposed therebetween. .

Next, the element 2 was impregnated with an electrolytic solution, a sealing member 3 made of rubber or the like was attached, and the element 2 was inserted into a case 4 made of aluminum or the like, and the opening of the case 4 was sealed.

When a high frequency current is passed through such an electrolytic capacitor,
In general, in the case of a metal case such as aluminum, although it is not a magnetic metal, it has been found that an extremely small loop current is generated at the bottom of the cylindrical metal capacitor case due to the magnetic flux caused by winding the aluminum electrode of the capacitor element.

However, when it comes to sound quality in audio technology, it is well known that loop current is a major cause of distortion in sound quality. Structures formed using rubber baking or resin, or resin cases instead of metal cases, are currently being used, but these are currently faced with many obstacles, such as increased man-hours and the inability to reuse existing equipment.

The present invention has been devised to eliminate the above-mentioned drawbacks, and provides an electrolytic capacitor whose loop current can be easily reduced or eliminated without significantly changing existing equipment or working methods.

In other words, it is known that when graphite is ground, carbon-carbon bonds are broken, causing a large change in magnetic susceptibility and inducing paramagnetism. Taking advantage of the property that heat treatment at 700℃ causes a large difference in magnetic receptivity, we focused on the characteristics of carbon and the fact that carbon has high conductivity even among non-metals, and stored it in a conventional resin case. After applying an electrolytic solution to the capacitor element of the electrolytic capacitor, applying a rated voltage to the electrodes of the element and measuring the potential difference between the top lead extraction side and the bottom side of the element, it was found that the bottom surface at the outer periphery This eliminates the disadvantage of having a high potential on the side and a potential difference of several mV to several lQmV.The present invention will be explained below with reference to the embodiment shown in Figure 2. The capacitor element 12 is formed by connecting the lead terminals 11 by caulking or the like, and winding or laminating them with electrolytic paper interposed therebetween.

(b) After impregnating the capacitor element 12 with an electrolytic solution obtained by mixing ethylene glycol, glycerin, boric acid, and aqueous ammonia, or a gel electrolyte obtained by adding a gelling agent thereto, the element 12 All or one surface except the 11 surface of the lead terminal has a particle size of 0.1 to 0.5μ.
It is coated with a solid solution 15 of polycrystalline graphite ground to m.

(c) The capacitor element 12 is housed in a bottomed cylindrical aluminum case 14, and the opening of the case is sealed tightly.

This is an electrolytic capacitor configured as described above.

In the above example, the polycrystalline graphite coating was applied to the surfaces of the capacitor element's lead terminals except for the surfaces of the lead terminals. However, it may be only the bottom surface or the peripheral surface.

In addition, in the example, polycrystalline graphite was used to coat the capacitor element, but even ground carbon such as acetylene black, carbon black, activated carbon, etc. ground to a particle size of 0.1 to 0.5 μm may be used. The effect is similar, and it is also possible to improve adhesion or coating workability with the capacitor element by mixing ground carbon and a driving electrolyte consisting of a gel electrolyte.

By configuring the present invention as described above, the magnetic flux generated by the capacitor element perpendicular to the bottom surface of the capacitor case is prevented by the paramagnetism of the ground carbon at the bottom surface of the capacitor case, and does not permeate perpendicularly. Its path is then bent, and the loop current generated at the bottom of the metal case is reduced or eliminated.

This is thought to be due to the carbons acting as an electrostatic shield, and even when a resin case is used, the electrical potential difference on the element surface decreases or disappears due to the conductivity of the carbons.

Further, as described above, ethylene glycol, glycerin, boric acid, and aqueous ammonia are mixed into the capacitor element 12, which is formed by caulking and connecting the external lead terminals 11 to the anode foil and the cathode foil, and winding them through electrolytic paper. After impregnating the obtained electrolytic solution or a gelled electrolyte obtained by adding a gelling agent thereto, carbon black is applied to the entire surface of the capacitor element 12 except for the drawing surface of the drawing lead terminal 11 as shown in FIG. Once deposited, the carbon black is uniformly coated with the electrolytic solution or gel electrolyte described above to form a solid solution 15 of polycrystalline graphite.

The element 12 is then placed in a bottomed cylindrical aluminum case 14.
An electrolytic capacitor (rated at 50WV, 1000μF) according to an embodiment of the present invention, in which the case opening is sealed with a seal
Figure 3 shows a distortion rate characteristic diagram of a conventional electrolytic capacitor (rated 5QWV, 1000μF) configured as shown in Figure 1, where A is an example of the present invention, and Figure 3 is an example of the conventional electrolytic capacitor. It is.

As is clear from the figure, the electrolytic capacitor in which the capacitor element is coated with the polycrystalline graphite solid solution of the present invention is 30KH2
It can be seen that the distortion rate is significantly improved, and there is a remarkable effect.

In addition, when the electrolytic capacitor of this invention was installed in the power supply circuit of an audio system and listened to, it was proven that the three-dimensional effect was improved and the sound quality was superior compared to conventional electrolytic capacitors. .

As mentioned above, the electrolytic capacitor of the present invention has polycrystalline graphite coated on the desired circumferential side of the capacitor element except for the lead terminals, so short circuits between the lead terminals do not occur, and the sound quality is improved in the sound range. The sense of distortion disappears, the bass sounds become more concentrated, the distortion rate characteristics in the high frequency range are greatly improved, and the tertiary high frequency is significantly reduced, making it possible to achieve high fidelity when used in audio systems and various audio transmission systems. It has a remarkable effect.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional electrolytic capacitor, Fig. 2 is a cross-sectional view of an embodiment of the electrolytic capacitor of the present invention, and Fig. 3 is a distortion rate characteristic diagram of the electrolytic capacitor. This is an example product. 11: Output lead terminal, 12: Capacitor element, 13:
Sealing plate, 14 aluminum case, 15: solid solution of polycrystalline graphite.

Claims (2)

[Scope of utility model registration request] (1) In an electrolytic capacitor having a capacitor element wound or laminated between electrode foils with electrolytic paper interposed therebetween, polycrystalline graphite, acetylene black, An electrolytic capacitor characterized by being covered with one or more ground carbons such as carbon black and activated carbon, or a solid solution containing the ground carbons. (2) The electrolytic capacitor according to claim 1, wherein the solid solution is formed of a mixture of ground carbon and gel electrolyte.