JPH06194252A - Detector for electrolyte leakage in electrolytic capacitor - Google Patents

Abstract

PURPOSE:To easily and electrically detect the leakage of electrolyte in an electrolytic capacitor. CONSTITUTION:A printed board for detection where conductive patterns 1 and 2 leave a space between them is attached between an electrolytic capacitor 5 and the printed board where the capacitor is mounted thereon and is connected therewith. When the electrolyte in the capacitor 5 would leak, the resistance value between the patterns 1 and 2 will decrease, so the decrease in the resistance value is detected by a detecting section 4. The section 4 outputs a detection signal of electrolyte leakage with a high level from a detection output terminal 9, when the voltage drop inputted from a resistor 7 due to the decrease in the resistance value between the patterns 1 and 2 becomes below a threshold, with an aid of the threshold of an inverter 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic capacitor liquid leak detection device for detecting leakage of electrolytic solution from an electrolytic capacitor. The electrolytic capacitor of the aluminum electrolytic capacitor has an electrolytic solution, is housed in a sealed case together with the electrodes so that the electrolytic solution does not leak, and only the terminals of the electrodes are led out. If the electrolytic solution of such an electrolytic capacitor leaks from the sealed case for some reason, a short circuit may occur between the wirings. Therefore, it is necessary to detect such leakage of the electrolytic solution at an early stage.

[0002]

2. Description of the Related Art Electrolytic capacitors, which have a large capacity, have the advantage of being relatively small and are often used in power supply circuits and other circuits. When the electrolytic solution of the electrolytic capacitor leaks, the capacity of the electrolytic capacitor is lost. Therefore, conventionally, the electrolytic capacitor having the missing capacity has been detected and replaced.

However, if the electrolytic solution completely leaks from the hermetically sealed case to the state where the capacity is zero or close to it, the capacity omission can be detected relatively easily, but it takes a considerable time before that. It will be. Further, when a plurality of electrolytic capacitors are connected in parallel, when a capacity loss occurs due to leakage of the electrolytic solution of one electrolytic capacitor, it is necessary to disconnect and detect the capacitance, which cannot be easily detected. .

[0004]

In addition to the capacity loss of the electrolytic capacitor due to the leakage of the electrolytic solution as described above, the leaked electrolytic solution flows between the wirings of the printed circuit board or the like and corrodes between the wirings, so that the wiring is Leakage current flows between them, and the insulating material of the printed board is carbonized along the path along which the leakage current flows. Due to the progress of this carbonization, the leakage current flowing between the wirings increases and finally fires, and in the worst case, a fire occurs. Since the leakage of the electrolytic solution to the occurrence of the fire gradually progresses, it is necessary to detect the leakage of the electrolytic solution at an early stage. However, in various electronic devices, it is difficult to observe from the outside due to the housing or the like. The present invention prevents leakage of the electrolytic solution of the electrolytic capacitor,
The purpose is to detect electrically easily.

[0005]

The electrolytic capacitor liquid leakage detection device of the present invention will be described with reference to FIG. 1. Conductor patterns 1 and 2 having a space therebetween are formed, and an electrolytic capacitor 5 and this electrolytic capacitor are formed. A printed circuit board for detection 3 mounted between the printed circuit board to which the capacitor 5 is connected and a detection unit 4 for detecting a decrease in resistance value between the conductor patterns 1 and 2 when the electrolytic solution of the electrolytic capacitor 5 leaks. Be prepared.

[0006]

If the detection printed board 3 is mounted between the electrolytic capacitor 5 and the printed board and the electrolytic solution of the electrolytic capacitor 5 leaks, the resistance value between the conductor patterns 1 and 2 is lowered by the electrolytic solution. This is detected by the detection unit 4,
An alarm can be sent when the resistance value drops below a predetermined value.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an embodiment of the present invention.
Reference numeral 2 is a conductor pattern, 3 is a printed circuit board for detection, 4 is a detection unit, 5 is an electrolytic capacitor, 6 is a hole for penetrating a terminal, 7 is a resistor, 8 is an inverter, and 9 is a detection output terminal.

The detection printed circuit board 3 on which the conductor patterns 1 and 2 are formed is mounted between the electrolytic capacitor 5 and the printed circuit board. At that time, connect the terminal of the electrolytic capacitor 5 to the hole 6
The conductor patterns 1 and 2 are formed in parallel with each other at intervals so as not to contact the terminals of the electrolytic capacitor 5. Further, one conductor pattern 1 is grounded, and the other conductor pattern 2 is connected to the input terminal of the inverter 8 of the detection unit 4.

In this embodiment, the common conductor patterns 1 and 2 are formed on a plurality of electrolytic capacitors 5 so that even if the electrolytic solution of any one of the electrolytic capacitors 5 leaks, the detecting section 4 can commonly detect it. Although the case is shown, it is also possible to separately provide the conductor patterns 1 and 2 corresponding to the electrolytic capacitor 5, and also provide the detection unit 4 corresponding to the electrolytic capacitor 5 to detect the electrolyte leakage corresponding to the electrolytic capacitor 5. is there.

The detection section 4 shows the case where the threshold value of the inverter 8 is used. When the resistance between the conductor patterns 1 and 2 is as large as infinity, the inverter 8 is connected via the resistance 7.
Since the voltage V is applied to the input terminal and the input is at the high level, the output signal of the inverter 8 becomes at the low level.

However, when the electrolytic solution of the electrolytic capacitor 5 leaks and straddles the conductor patterns 1 and 2, the resistance value between the conductor patterns 1 and 2 decreases, and the input voltage of the inverter 8 decreases. When the input voltage drops below the threshold value of the inverter 8, the output signal of the inverter 8 becomes high level. That is, a high-level electrolyte leakage detection signal is output from the detection output terminal 9. The detection unit 4 can also be formed on the detection printed board 3. Thereby,
The electrolytic capacitor 5 can be easily handled as an electrolytic solution leak detection device.

FIG. 2 is a cross-sectional view of an essential part of an embodiment of the present invention, showing a case where the electrolytic capacitor 5 is mounted on the printed circuit board 10 via the printed circuit board 3 for detection, and the terminal 5A of the electrolytic capacitor 5 is detected. The hole 6 of the printed circuit board 3 is penetrated and soldered to the wiring 11 of the printed circuit board 10 to be connected. The detection printed circuit board 3 has conductor patterns 1 and 2 as shown in FIG. 1, and the detection unit 4 is connected to the conductor patterns 1 and 2.

Since the printed circuit board 3 for detection is merely interposed between the electrolytic capacitor 5 and the printed circuit board 10, it does not require mechanical strength, and therefore has a thickness larger than that of the printed circuit board 10. Can be thinned. Further, since the detection printed board 3 is sandwiched between the electrolytic capacitor 5 and the printed board 10, it is not necessary to separately fix it, but, for example, it is easily fixed with an adhesive or wiring is used. It is also possible to fix it by soldering. When an alarm circuit or the like is mounted on the printed circuit board 10 and the detection unit 4 is mounted on the detection printed circuit board 3, the detection printed circuit board 3 is fixed on the printed circuit board 10 and the detection unit 4 is also mounted. It suffices to connect the detection output terminal of 1 to the alarm circuit of the printed circuit board 10.

FIG. 3 is a measurement curve diagram showing the relationship between the width of the electrolyte and the resistance value with respect to the conductor pattern. The horizontal axis represents the width of the electrolyte [m.
m], and the vertical axis represents the resistance value [kΩ]. The resistance value between the conductor patterns 1 and 2 was measured when the width W of the conductor patterns 1 and 2 was 1 mm, the gap G was 1.5 mm, and the width X of the electrolytic solution 20 was sequentially increased to about 6 mm.

For example, when the electrolytic solution 20 of the electrolytic capacitor 5 is normal and the electrolytic solution width X is 0, the resistance value between the conductor patterns 1 and 2 is close to infinity. Further, the electrolytic solution 20 of the electrolytic capacitor 5 leaks and flows between the conductor patterns 1 and 2, and the width X of the electrolytic solution 20 is 3 mm.
Then, the resistance value between the conductor patterns 1 and 2 is 100 kΩ.
Becomes

Therefore, when detecting at this time, for example, when the threshold value of the inverter 8 is V / 2, the resistance 7 is set to 1
It is good to select it as 00 kΩ. Therefore, the electrolytic solution 20 of the electrolytic capacitor 5 leaks, and the conductor patterns 1, 2
When the width X is 3 mm or more, the electrolyte leakage detection signal is output from the detection output terminal 9 of the detection unit 4.

Since various electronic devices are generally provided with a configuration for detecting an abnormal state of each part and outputting an alarm, an electrolytic capacitor is utilized by utilizing such an alarm output function. It is possible to output an alarm due to the leakage detection of the electrolytic solution of item 5. Therefore, an accident such as a fire caused by the electrolytic solution can be prevented.

The present invention is not limited to the above-described embodiment, and for example, the detection unit 4 shows the case where the threshold value of the inverter 8 is used, but the threshold value of another gate circuit is used. You can also It can also be configured by a comparison circuit or the like for comparing with a reference value. Also, the conductor patterns 1 and 2 are not limited to the case of a straight line,
In consideration of the terminal structure, etc., the pattern can be arbitrary.

[0019]

As described above, according to the present invention, the printed circuit board for detection 3 having the conductor patterns 1 and 2 spaced from each other is mounted between the electrolytic capacitor 5 and the printed circuit board. The detection unit 4 detects the decrease in the resistance value between the conductor patterns 1 and 2 when the electrolytic solution of No. 5 leaks, and the occurrence probability of the electrolytic solution of the electrolytic capacitor 5 is extremely small. When the electrolyte leaks, it may cause an unexpected situation, so that it can be prevented by the detection printed circuit board 3 and the detection unit 4, and various electronic devices using the electrolytic capacitor 5 can be prevented. There is an advantage that the reliability of the device can be further improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of an embodiment of the present invention.

FIG. 3 is a relationship measurement curve diagram of an electrolytic solution width and a resistance value with respect to a conductor pattern.

[Explanation of symbols]

 1, 2 conductor pattern 3 printed circuit board for detection 4 detection unit 5 electrolytic capacitor 6 hole 8 inverter

Claims (1)

[Claims] 1. A printed circuit board for detection, which is provided with conductive patterns (1), (2) spaced apart from each other and is mounted between an electrolytic capacitor (5) and a printed circuit board connecting the electrolytic capacitor (5). (3) and a detection unit (4) for detecting a decrease in the resistance value between the conductor patterns (1) and (2) when the electrolytic solution of the electrolytic capacitor (5) leaks. Electrolytic capacitor liquid leak detection device.