JPS63254716A - Voltage doubler circuit and capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a voltage doubler circuit used when applying high voltage to a magnetron, and more particularly to a voltage doubler circuit formed by connecting a capacitor and a diode in series. It is.

2. Description of the Related Art Generally, this type of voltage doubler circuit has the configuration shown in FIG. 3, where T is a transformer, C is a capacitor, D is a diode,
M is a magnetron. The capacitor C used in this voltage doubler circuit had the configuration shown in FIG. That is, the electrode 3 - plastic film 1 - paper 2 - electrode 3-layer plastic film 1' - paper 2' were wound in this order. In this capacitor C, electrode 3 was connected to point a in FIG. 2 as a positive electrode, and electrode 3' was connected to point a as a negative electrode. The equivalent circuit of this capacitor C is shown in FIG.

In addition, in FIG. 6, C1 is the plastic film 1.
C: is the equivalent capacitor of plastic film 1゛, C2 is the equivalent capacitor of paper 2, C゛2
is an equivalent capacitor of 2 degrees of paper 0 Problems to be Solved by the Invention In the above configuration, the voltage waveform of capacitor C becomes as shown in FIG. There was a problem in that the paper 2' was easily broken.

Means for Solving the Problems In order to solve the above problems, the voltage doubler circuit of the present invention is constructed by disposing a plastic film on the positive electrode side of the capacitor.

Effect: The above configuration defines the arrangement of the electrodes and dielectric of the capacitor, and improves the withstand voltage of the capacitor.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The voltage doubler circuit of this embodiment is similar to the general voltage doubler circuit shown in FIG. 3, but is characterized by the specific structure of the capacitor C.

That is, the configuration of capacitor C is as shown in Figure 1.
The electrode 3-plastic film 1-paper 2-electrode 3'-paper 2'-plastic film 1' are wound in this order. Electrode 3 of this capacitor C is the third
The electrode 3' is connected to point a in the figure and becomes a positive electrode, and the electrode 3' is connected to point a and becomes a negative electrode. The equivalent circuit of this capacitor C is shown in Fig. 2. In this Fig. 2, C1 is an equivalent capacitor of plastic film 1, C2 is an equivalent capacitor of paper 2, and C' is an equivalent capacitor of plastic film 1'. , C゛2 is the equivalent capacitor of 2 degrees of paper.

As a specific example of this embodiment, plastic films 1, 1
18 μm thick polypropylene film was used for ′, 6 μm thick paper was used for paper 2 and 2°, aluminum foil electrodes were used for electrodes 3 and 3′, and further impregnated with diallylethane.
tF capacitors (4) were created, a voltage doubler circuit shown in Figure 3 was constructed, and a DC component of 1,700 V and an AC component of 2,360 V were superimposed and applied at an ambient temperature of 60'C.Furthermore, five capacitors were The time required for capacitor C to break down was investigated by constructing a voltage doubler circuit using each of them, and the results are shown in Fig. 7. In Fig. 7, the solid line I indicates this example, and after 2000 hours, the Six capacitors were not destroyed.

In addition, in FIG. 7, the dotted line ■ indicates the case where the capacitor shown in FIG. 1 (using the same material as in this example) is used, but electrode 3 is connected to point a, and electrode 3' is connected to point a. Yes, 2
By the time 000 hours had passed, three of the five capacitors had been destroyed.

Furthermore, in FIG. 7, the dotted line ■ is the case when the capacitor shown in FIG.
The capacitor in the machine was destroyed.

These results revealed that by connecting the capacitor with the polypropylene film (plastic film) on the positive electrode side, excellent voltage resistance was achieved.

Effects of the Invention As described above, according to the present invention, by placing a plastic film on the positive electrode side of the capacitor, the withstand voltage property of the capacitor can be improved and a highly reliable voltage doubler circuit can be provided.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a capacitor used in a voltage doubler circuit showing an embodiment of the present invention, Fig. 2 is an equivalent circuit of the same capacitor, Fig. 3 is a circuit diagram of the voltage doubler circuit, and Fig. 4 is a conventional Schematic cross-sectional view of a capacitor used in the voltage doubler circuit, No. 5
The figure is an equivalent circuit diagram of the same capacitor, Figure 6 is a voltage waveform diagram of the capacitor in the voltage doubler circuit shown in Figure 3, and Figure 7 is a diagram showing the relationship between the energization time and the number of remaining capacitors in the voltage doubler circuit. . 1.1'...Plastic film, 2.2'
...Paper, 3.3' ...Electrode, C...
...Capacitor, D...Diode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 ■ Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Kenma CHF3

Claims (1)

[Claims] A voltage doubler circuit comprising a capacitor and a diode connected in series, wherein paper and plastic film are used as the dielectric of the capacitor, and a plastic film is placed on the positive electrode side of the capacitor.