JPH118168A - Device for aging electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a switching power supply against a failure by a method wherein the switching-type power supply which applies a voltage to an electrolytic capacitor needed to the aged and a Nichrome wire connected between the switching-type power supply and the electrolytic capacitor are provided. SOLUTION: An electrolytic capacitors C1 to Cn to age are mounted on a jig A1 and connected in parallel between terminals a and b. The terminal a of the jig A1 is connected to the position potential side of the switching power supply 1 through a diode 3 and a Nichrome wire 2, and the other terminal b of the jig A1 is connected to the negative potential side of the switching power supply. Therefore, the Kichrome wire 2 is made to serve as a protective resistor, so that even if any of the electrolytic capacitors C1 to Cn causes a short circuit and gets damaged, the switching power supply 1 can be surely protected against damage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aging apparatus for an electrolytic capacitor, and more particularly, to a technique for protecting a power supply when a short circuit is broken during aging using a switching type power supply.

[0002]

2. Description of the Related Art Generally, an electrolytic capacitor is formed by interposing an electrolyte between an anode electrode and a cathode electrode each having an oxide film such as a metal oxide formed on a surface thereof. For example, in a foil type electrolytic capacitor, the surface of a metal foil such as aluminum constituting the anode electrode is oxidized to a metal oxide film of aluminum oxide, which is opposed to the cathode electrode of the metal foil such as aluminum via an electrolyte solution. Let me.

In the manufacturing process of such an electrolytic capacitor, a part of the metal oxide film may be damaged.
This breakage of the metal oxide film degrades the performance of the electrolytic capacitor or renders it unusable. Therefore, after assembling the electrolytic capacitor, aging is performed to re-form the metal oxide film of the electrolytic capacitor to repair the metal oxide film. This aging is performed by applying a re-forming voltage determined by characteristics such as the capacity and withstand voltage of the electrolytic capacitor to both electrodes of the electrolytic capacitor for an appropriate time.

As a DC power supply for supplying a voltage for aging an electrolytic capacitor, a power supply of a dropper type has conventionally been used, but recently, along with a demand for downsizing of equipment, the size and weight can be reduced. Switching power supplies are being used. If a short circuit occurs in the circuit, such as a short-circuit breakdown of the electrolytic capacitor during aging, the switching power supply may damage the output FET and the like before the protection circuit operates, and the power supply body may be damaged. As a method for preventing the switching power supply from being damaged or broken due to such a short circuit, generally, a fixed resistor is connected as a protective resistance element between the electrolytic capacitor and the switching power supply.

[0005]

In aging, since a current of several A may flow from a low voltage stage, it is necessary to select several Ω as a resistance value of a fixed resistor as a protection resistor. Also, even if the electrolytic capacitor is short-circuited, the fixed resistor itself must not be burned by Joule heat, and the fixed resistor has a power capacity of several tens W to 100 W.
A large resistor was needed. Therefore, it is difficult to reduce the size of the device, and the necessity of a large resistor increases the cost and raises a problem.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, it is an object of the present invention to provide a simple and inexpensive and small-sized structure for easily and surely suppressing the occurrence of failure of a switching power supply when an electrolytic capacitor is short-circuited. It is to provide an aging device for a capacitor.

Another object of the present invention is to provide an inexpensive and simple circuit for protecting a switching power supply when an electrolytic capacitor is short-circuited in an aging apparatus for an electrolytic capacitor.

[0008]

According to the present invention, there is provided a switching type power supply for applying a voltage to an electrolytic capacitor to be aged, and an electrolytic capacitor comprising a nichrome wire connected between the power supply and the electrolytic capacitor. An aging device is provided. With such a configuration, even if the electrolytic capacitor is short-circuited and destroyed during aging, the switching type power supply can be inexpensively and accurately protected.

Further, there is provided an aging apparatus for an electrolytic capacitor comprising a switching type power supply for applying a voltage to an electrolytic capacitor to be aged and a nichrome wire and a diode connected in series between the power supply and the electrolytic capacitor. . With such a configuration, even if the electrolytic capacitor is short-circuited and destroyed during aging, the switching type power supply can be properly protected at low cost, and furthermore, the reverse current can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An aging apparatus for an electrolytic capacitor according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic circuit of an electrolytic capacitor aging apparatus according to one embodiment of the present invention.

[0012] In FIG. 1, the jig A ₁ is equipped with a electrolytic capacitor C ₁ -C _n to be n number of aging example, they are connected in parallel between the terminals a and b. The number n of the electrolytic capacitors connected in parallel is arbitrarily set in consideration of the type of the electrolytic capacitor to be aged, the size of the power supply, and the like.

Jig A₁Terminal a of the diode 3
Via the nichrome wire 2 to the positive potential side of the switching power supply 1
It is connected. The diode 3 is connected to the switching power supply 1
From the positive potential side through Nichrome wire 2, diode 3, terminal a
Is an electrolytic capacitor C₁~ C _nIn the case where current flows through
Connected to the direction. Jig A₁The terminal b of
The switching power supply 1 is connected to the negative potential side.

FIG. 2 is a schematic diagram showing an example of the shape of the nichrome wire 2 used in the present embodiment. A nichrome wire having a wire diameter of 0.6 mm is wound so as to be about 3Ω. The number of turns of the nichrome wire can be adjusted according to a desired resistance value.
Next, the operation of the electrolytic capacitor aging device having such a configuration will be described.

First, in order to obtain a voltage required to re-form the electrolytic capacitors C _{1 to} C _n , the switching power supply 1
As a result, a DC voltage is applied between the terminals a and b. Thus, the electrolytic capacitor C ₁ -C _n is charged, the electrolytic capacitor inter-terminal voltage rises almost reached a constant value, is maintained appropriate time reformation of the electrolytic capacitor C ₁ -C _n is performed.

[0016] During the aging of the electrolytic capacitor _C 1 -C _n, and any electrolytic capacitors, for example, a short disruption in _{C 1} has occurred. If there is no nichrome wire 2, a large current flows due to short circuit, and the switching power supply 1 is an output FET
Will cause damage such as damage. In the aging device of this embodiment, the switching power supply 1 and is nichrome wire 2 is connected as a protective resistor between the electrolytic capacitor C _1, the resistance of the nichrome wire 2, even if the electrolytic capacitor C ₁ is destroyed short An overcurrent that would cause the switching power supply 1 to fail does not flow. The resistance value of the nichrome wire 2 is arbitrarily set in consideration of the type and number of electrolytic capacitors to be aged, the size of the switching power supply 1, the aging conditions, and the like. The electrolytic capacitors to be aged are connected in parallel, and it is necessary to flow a somewhat large current (for example, several A) even when the applied voltage of the switching power supply 1 is small. Therefore, the resistance value of the nichrome wire 2 is in a steady state during the aging. Is preferably several Ω.

The protective resistance for when the electrolytic capacitor C ₁ -C _n is broken short circuit protection resistor itself be a large current flows by short circuit of the electrolytic capacitor is not Senebanara to be such that they do not burn out by Joule heat. Therefore, when a fixed resistor is used as a protection resistor, a large resistor having a large power capacity is required. For example, if the resistance value of the protection resistor is 3Ω and the output of the power supply is 300V, 5A, a large resistor of 3Ω-75W is required (in this case, if the capacity of the resistor is smaller than 75W, there is a risk of burning. ).

If a nichrome wire is used as a protection resistor as in the aging device of this embodiment, even if a large current flows due to short-circuit breakdown of the electrolytic capacitor and the nichrome wire generates heat due to Joule heat, the nichrome wire is a material that can withstand high temperatures. There is no problem. Also, it is not necessary to make the nichrome wire so large. To act as a protective resistor,
For example, a nichrome wire having a size as shown in FIG. 2 is sufficient, and the size can be reduced. Since the allowable range of the current depends on the wire diameter of the nichrome wire, for example, when a large current is expected to flow, the wire diameter of the nichrome wire is increased. Since the resistance value of the nichrome wire depends on the length of the nichrome wire, the resistance value can be adjusted by the number of windings and the like. By using a nichrome wire as a protection resistor, a large resistor becomes unnecessary, and miniaturization and cost reduction become possible. Further, if current electrolytic capacitor C ₁ is destroyed short increases, nichrome wire 2 generates heat by resistance value is increased,
It also acts to suppress current. Therefore, the nichrome wire 2 also serves as a current limiter.

The diode 3 is connected to prevent reverse current, and prevents a discharge current from the electrolytic capacitors C _{1 to} C _n from flowing into the switching power supply 1.

In the case where a conventional apparatus not using a nichrome wire was used for the aging process, three out of 36 switching power supplies were damaged in three months, whereas the aging apparatus of this embodiment was tested for four months. When aging was performed, none of the 48 switching power supplies caused damage or failure. It was also confirmed that the switching power supply was not damaged even if the electrolytic capacitor was short-circuited during aging.

Although a specific embodiment has been described, the present invention relates to an aging apparatus for an electrolytic capacitor in which a voltage is applied to an electrolytic capacitor to be aged by a switching type power supply. Any structure that uses a nichrome wire may be used, and is not limited to the above-described embodiment.

[0022]

As described above, according to the present invention, by using a nichrome wire as a protection resistor, it is possible to reliably prevent the switching type power supply from being damaged even if the electrolytic capacitor is short-circuited during aging. . Further, a large resistor is not required, and the size and cost of the aging device can be reduced. Further, the nichrome wire generates heat due to an increase in current and increases the resistance value, and thus can be used as a current limiter.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of an aging device for an electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of the shape of a nichrome wire used in one embodiment of the present invention.

[Explanation of symbols]

First switching power supply 2 Nichrome wire 3 diode A ₁ jig _{C 1, C 2, ~,} C n electrolytic capacitor

Claims (2)

[Claims] 1. An aging apparatus for an electrolytic capacitor, comprising: a switching-type power supply for applying a voltage to an electrolytic capacitor to be aged; and a nichrome wire connected between the power supply and the electrolytic capacitor. 2. An electrolytic capacitor, comprising: a switching power supply for applying a voltage to an electrolytic capacitor to be aged; and a nichrome wire and a diode connected in series between the power supply and the electrolytic capacitor. Aging device.