JPS5834928B2 - non-inductive capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-inductive capacitor that can significantly reduce the inductance caused by electrode foil and increase the frequency limit of use.

Conventionally, structures shown in FIGS. 1 to 4 are known as structures in which electrode leads are provided on electrode foils.

Figure 1 shows an electrolytic capacitor in which paper 1, cathode foil 2, paper 3, and anode foil 4 are stacked as shown in figure a, and the winding is started from the starting end S and then wound as shown in the figure, and this is impregnated with electrolyte. shows.

The electrode leads 5 and 6 of this electrolytic capacitor are provided near the end E of the winding.

The capacitor shown in the second figure is made by stacking paper 1, cathode foil 2, paper 3, and anode foil 4 as shown in the figure a, and winding them starting from the starting end S and winding them as shown in the figure to impregnate them with electrolyte. It is something.

The cathode lead 5 is connected to the cathode foil 2 near the start end S, and the anode lead 6 is connected to the anode foil 2 near the winding end E.
It is connected to the.

The capacitor shown in Figure 3 is made by stacking paper 1, cathode foil 2, paper 3, and anode foil 4 as shown in Figure a, and then winding them starting from the starting end S and winding them as shown in Figure 3 to impregnate them with electrolyte. It is something.

The electrode leads 5 and 6 are connected to each electrode foil 2 and 4 near the center thereof, respectively.

The capacitor shown in Figure 4 is made by stacking paper 1, cathode foil 2, paper 3, and anode foil 4 as shown in Figure a, and winding them starting from the starting end S as shown in Figure 4, and impregnating them with electrolyte. It is.

Each electrode 2, 4 (respectively an arbitrary number of electrode leads 5,
5......and 6,6...
・These electrode lead groups are provided over the entire length at certain intervals, and these electrode lead groups are grouped into anodes and cathodes as shown in FIG.

In the capacitors shown in FIGS. 1 to 4, the impedance increases as the frequency of use increases due to the inductance of the electrode foil, and the upper limit of the frequency of use is quite low.

This invention virtually eliminates the inductance of the electrode foil,
The aim is to create a capacitor that can be used at high frequencies.

The present invention will be explained below with reference to FIGS. 5 and 6.

As shown in FIG.
and 6S are provided, respectively, and electrode leads 5E and 6E are provided at the winding ends E of both electrode strips 2 and 4, respectively.

Then, the electrode foils 2 and 4 are shifted so that opposite sides O are exposed from the papers 1 and 3, and the papers 1 and 3 and the electrode foils 2 and 4 are wound from the starting end S, as shown in FIG. The element 7 is wound up into a shape such that the electrode foils 2 and 4 are exposed from the end face of the element, and is impregnated with an electrolytic solution.

As shown in FIG. 6, the element I is housed in an aluminum container 8 and fixed with a fusible insulating material 9. As shown in FIG.

Electrode leads 5S, 5E, 6S of element 7. 6E connects the lid 1 to the terminals 11, 12° 13.14 provided on the lid 10 made of insulators.
The opening of the container S is sealed 1. ) to be done.

In addition, instead of making the capacitor into a half-shaped capacitor as shown in FIGS. 5 and 6, as shown in FIG.
The set of electrode leads 5E, 6E and 5S, 6S are connected to element 7.
It can also be made into a tubular shape by leading out at both ends.

FIG. 8 shows an example in which the electrolytic capacitor embodying the above-described invention is applied to a power supply circuit.

The pulsating current obtained by rectifying the alternating current AC by the rectifier 16 is given to the electrolytic capacitor element 7, flows through the anode foil 4, then flows through the load 17, and on the return path flows through the cathode foil 2 again and returns to the rectifier 16.

In this application, electrode leads 5E and 6 are shown.
Connect E to the rectifier 16 side, and connect electrode leads 5S and 6S.
Connect the electrode leads 5S and 6S to the rectifier 16 side, or connect the electrode leads 5S and 6S to the rectifier 16 side.
It was observed that when E and 6E were connected to the load 17 side, the impedance of the capacitor became particularly small.

FIG. 9 shows the frequency characteristics at 25°C of the conventional electrolytic capacitors shown in FIGS. 1 to 4, respectively, with curves 21.
22, 23, and 24, and a curve 25 shows the frequency characteristic at 25° C. of the embodiment of FIG. 5 of the present invention.

A curve 26 shows the impedance of the capacitor shown in FIG. 5 of the present invention, in which the cathode foil 2 and the anode foil 4 are stacked and wound with papers 1 and 3 without being shifted so that they are exposed on opposite sides.

Also, the dotted line 20 shows the theoretical impedance of the capacitor represented above.

Here, each capacitor has a length of 2500 mm and a width of 5
0mm cathode foil and anode foil are wound, and the rating is 470
It is 0μF and 50WV.

According to Figure 9, the conventional electrolytic capacitor is 2 K) Iz
The influence of inductance begins to appear in the vicinity, and the impedance does not become less than 0.02.2, but in the embodiment of this invention, the frequency at which the influence of inductance begins to appear is at least one order of magnitude higher, and the minimum impedance is also at least one order of magnitude lower. I understand.

The capacitor shown by curve 26 in Figure 9 is 10 to 100 K.
Hz, the impedance is particularly low (which is desirable), but when the electrode foil is used in a circuit, heat is generated due to the superimposed load current and ripple current flowing through the electrode foil, and as a result, the current flowing through the capacitor increases and the temperature rises. It rises rapidly which is not desirable.

However, when the capacitor of the present invention shown by curve 25 is used in a circuit, heat is generated due to the superimposed load current and ripple current flowing through the G electrode foil, and therefore, as the current flowing through the capacitor increases, the temperature rises. As shown in Fig. 5, the cathode foil 2 and the anode foil 4 are stacked and wound with the papers 1 and 3 in a shifted manner so that they are exposed on opposite sides, so that the structure is of a so-called non-inductive type (heat dissipation type). It has good heat dissipation and can reduce temperature rise.

In recent years, in inverters that change DC voltage, in order to downsize the device, AC is generated at the highest possible frequency and then transformed and rectified. The maximum frequency was about 10 KHz, and unnecessarily large capacitance capacitors were required.

However, if the capacitor according to this invention is used, 2 M
It is possible to increase the AC usage to about B,z, and even with the same rated capacity compared to conventional electrolytic capacitors,
It is possible to exhibit a capacitance effect that is orders of magnitude larger.

The capacitor of the present invention not only has improved high frequency characteristics, but also has a structure in which the cathode foil and the anode foil are staggered so that they are exposed on opposite sides, thereby making it possible to reduce temperature rise.

As described above, according to the present invention, the inductance caused by the electrode foil of the capacitor can be reduced, the frequency limit of the capacitor can be increased, and the capacitance effect can also be increased.

[Brief explanation of the drawing]

1 to 4 are explanatory diagrams and a sketch of a conventional capacitor element, FIG. 5 is an explanatory diagram and a sketch of a capacitor element according to the present invention, and FIG. 6 is a vertical cross-section of a capacitor according to the present invention. 7 is a longitudinal cross-sectional view of a capacitor according to another embodiment of the present invention, FIG. 8 is a wiring diagram of a power supply furnace circuit using the capacitor of this invention, and FIG. It is a frequency characteristic curve diagram of the capacitor which was carried out. 1 and 3: paper, 2 and 4: electrode foil, 5S and 6S
: Electrode lead at the beginning of the winding, 5E and 6E: Electrode lead at the end of the winding, 7: Capacitor element.

Claims (1)

[Claims] 1. A pair of band-shaped electrode foils and a dielectric layer are interposed between them, and the electrode foils are wound so that their end faces are exposed on opposite sides of the dielectric layer, and the electrode foils are wound around the beginning of winding of each electrode foil and A non-inductive capacitor characterized by having a four-terminal configuration with electrode leads attached to each near the end of the winding.