JP2010197284A - Abnormality detection device of electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a phenomenon wherein a safety valve of an electrolytic capacitor C1 is operated and electrolytic solution inside the electrolytic capacitor C1 blows out, at an abnormal time such as at the end of lifetime or in the case of overvoltage of the electrolytic capacitor C1 loaded on a high-frequency conversion circuit 100. <P>SOLUTION: The high-frequency conversion circuit 100 having an AC/DC conversion circuit 10 loaded with the electrolytic capacitor C1, and a power supply circuit 20 connected to the AC/DC conversion circuit 10, for supplying a high-frequency AC current to a load Ld includes a detection circuit 30 for detecting the high-frequency AC current, wherein a high-frequency voltage dividing capacitor C11 whose capacity is changed corresponding to a temperature change is arranged near the electrolytic capacitor C1, and abnormal heat generation of the electrolytic capacitor C1 is detected by the high-frequency voltage dividing capacitor C11, and at least either of a voltage and a current applied to the electrolytic capacitor C1 is cut off or reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for detecting an abnormality of an electrolytic capacitor in an electronic device equipped with the electrolytic capacitor.

  For example, in an electrolytic capacitor, an aluminum electrode of cathode and anode and electrolytic paper are overlapped and wound into a roll shape and stored in an aluminum case. An external terminal is welded from the aluminum electrode of the cathode and the anode and is taken out of the case. The inside is filled with an electrolytic solution and sealed with a sealing rubber. The head of the aluminum case generally has a slit called a safety valve. This is due to an increase in the loss angle (tan δ) inside the electrolytic capacitor, etc., and the inside of the capacitor generates heat. When the electrolyte rapidly evaporates and the internal pressure rises sharply, this slit portion tears, and the internal pressure is released to the outside air. .

  There is an electrolytic solution inside the electrolytic capacitor, and when the electrolytic capacitor generates heat, the electrolytic solution evaporates and the internal pressure of the electrolytic capacitor increases. Even in the initial state, there is internal heat generation and the electrolytic solution evaporates, but it passes through the sealing rubber and maintains the balance between the internal pressure and the outside air. However, when used for a long time, the electrolytic solution decreases and the loss angle (tan δ) of the capacitor increases. As the loss angle increases, the inside of the electrolytic capacitor generates heat, and the evaporation of the electrolyte is promoted.Thus, the permeation from the sealing rubber becomes insufficient, and the internal pressure of the electrolytic capacitor rises, so the safety valve at the head tears, There is a case where the internal electrolyte solution spouts out to the outside in the form of water vapor.

  This phenomenon occurs not only when used for a long time, but also when the voltage applied to the capacitor exceeds the rated voltage or when a reverse voltage is applied, and the electrolyte remains sufficiently. When generated in a state, more electrolytic solution is ejected in the form of water vapor. The main component of the electrolyte is ethylene glycol, and the boiling point is about 200 ° C.

  For example, electrolytic capacitors are also used in high-frequency conversion circuits such as switching power supplies and inverter circuits. Electrolytic capacitors have a capacitance of several μF to several hundred μF and a rated voltage of several V to several hundred V. Electrolytic circuit abnormalities and the inside of the electrolytic capacitor generate heat at the end of the life of the electrolytic capacitor. The liquid evaporates and the safety valve opens, and the electrolyte is ejected in the form of water vapor.

  This phenomenon may be perceived as smoke generated by combustion for the end user using electronic equipment. In order to avoid this phenomenon, a technique (for example, Patent Document 1) that electrically detects a change in the current flowing through the electrolytic capacitor and an applied voltage (for example, Patent Document 1), or a temperature sensitive element in which the heat generated by the electrolytic capacitor is incorporated in the electrolytic capacitor. There exists a technique (for example, patent document 2) detected by the above.

Japanese Patent Publication No. 4-59592 (see page 3, left column, line 36 to right column, line 10; see FIG. 1) JP-A-4-233214 (see paragraph “0010”, FIG. 1)

  However, the current flowing through the electrolytic capacitor and the applied voltage vary depending on the characteristics of the electrolytic capacitor used, the electronic equipment, and the surrounding environment, and the method for detecting this current and voltage complicates the circuit for accurate detection. There is a problem that it is difficult to design.

  There is a structure that detects the abnormal temperature by contacting the temperature sensitive element with the electrolytic capacitor using a special case for the electrolytic capacitor. However, when applied to a small electrolytic capacitor, the structure becomes complicated and fine processing technology is required. Is not practical.

  The present invention provides an abnormality detection device for an electrolytic capacitor that can prevent the electrolytic solution from being ejected in the form of water vapor by separating the electrolytic capacitor from the circuit of the electronic device when the electrolytic capacitor mounted on the electronic device generates heat during an abnormality. The purpose is to do.

  The electrolytic capacitor abnormality detection device of the present invention includes a rectifier circuit that rectifies an AC voltage, an AC / DC converter circuit that has an electrolytic capacitor that smoothes the voltage rectified by the rectifier circuit, and is connected to the AC / DC converter circuit. An inverter circuit that converts the smoothed DC voltage into a high-frequency AC voltage, a load circuit to which the high-frequency AC voltage output from the inverter circuit is applied, and a high-frequency voltage dividing capacitor that detects the high-frequency AC voltage of the load circuit And a detection circuit that outputs a detection signal according to the voltage value of the high-frequency voltage divider capacitor, and the high-frequency voltage divider capacitor of the detection circuit changes capacitance according to a temperature change, Arranged close to the electrolytic capacitor.

  According to the present invention, when an electrolytic capacitor mounted on an electronic device abnormally generates heat, the temperature rise is detected to prevent the electrolytic capacitor's safety valve from operating, and the electrolytic solution can be discharged as water vapor. Can be prevented.

3 is a circuit diagram illustrating a high-frequency conversion circuit according to Embodiment 1. FIG. FIG. 3 is a perspective view showing a capacitor arrangement in the first embodiment. FIG. 3 is a diagram showing characteristics of a ceramic capacitor for detection in the first embodiment. 6 is a diagram illustrating a high-frequency conversion circuit according to Embodiment 2. FIG. FIG. 6 is a diagram showing a high-frequency conversion circuit in a third embodiment. FIG. 10 is a diagram illustrating a high-frequency conversion circuit in a fourth embodiment.

Embodiment 1 FIG.
FIG. 1 is a circuit diagram of the high-frequency conversion circuit of the present embodiment.

First, the circuit configuration of the high-frequency conversion circuit 100 will be described.
The AC / DC converter circuit 10 that receives the commercial power supply AC and converts an AC voltage into a DC voltage, and converts the voltage output from the AC / DC converter circuit 10 into electric power corresponding to the connected load Ld, and supplies the electric power to the load Ld. A power supply circuit 20 that supplies power and a detection circuit 30 that detects a current supplied to the load Ld by the power supply circuit 20 are provided.

  The AC / DC converter circuit 10 includes a rectifier circuit 11 that rectifies an AC voltage to which a commercial power supply AC is input, and a boost chopper circuit 12 that boosts a voltage output from the rectifier circuit 11.

  The rectifier circuit 11 includes a current fuse F connected to an input terminal to which the commercial power supply AC is input, and a diode bridge DB1 connected via the current fuse F.

  The step-up chopper circuit 12 includes pulsating voltage detection resistors R4 and R5 connected in parallel to the output terminal of the rectifier circuit 11, a switching element Q1 connected via a transformer T1, and a current detection resistor R6 flowing through the switching element Q1. A switching diode D1 connected to the transformer T1 and the anode side, an electrolytic capacitor C1 connected to the cathode side of the switching diode D1 and the low potential side of the rectifier circuit 10, and connected in parallel to the electrolytic capacitor C1 Output voltage detection resistors R1 and R2 for detecting the voltage charged in the capacitor C1, detection signals detected by the pulsating voltage detection resistors R4 and R5, the output voltage detection resistors R1 and R2, and the current detection resistor R6 of the switching element Q1; Input detection signals generated on the secondary side of the transformer T1, and based on these detection signals , And a step-up chopper control circuit 13 which controls the boost chopper circuit 2.

  The power supply circuit 20 includes a load circuit 21 to which a load Ld is connected, and an inverter that converts the voltage output from the boost chopper circuit 12 into a high-frequency AC voltage and supplies power to the load Ld connected through the load circuit 21 A circuit 22 is provided.

  The inverter circuit 22 includes switching elements Q2 and Q3 connected in series, and a switching control circuit 23 that generates a signal for alternately turning on and off the switching elements Q2 and Q3 at a high frequency.

  The load circuit 21 is connected to the load Ld from the connection point of the switching element Q2 and the switching element Q3 via the ballast choke L20, and includes a series resonant circuit including a DC voltage component removing capacitor C20 for removing a DC component between the load Ld and the ground. It has.

  The detection circuit 30 includes high-frequency voltage dividing capacitors C10 and C11 connected in series to a connection point between the ballast choke L20 of the load circuit 21 and the load Ld, a diode D11 connected in parallel with the high-frequency voltage dividing capacitor C11, and a diode A diode D10 connected between the cathode of D11 and the inverting input terminal of the comparator IC10, a resistor R12 and a capacitor C12 connected between the inverting input terminal of the comparator IC10 and the ground, and each control circuit of the high-frequency conversion circuit 100 A resistor R10 connected between the DC power supply Vcc serving as a power source and the non-inverting input terminal of the comparator IC10, and a resistor R11 connected between the non-inverting input terminal of the comparator IC10 and the ground are provided.

  The output terminal of the comparator IC 10 is connected to the boost chopper control circuit 13 of the boost chopper circuit 12 and the switching control circuit 23 of the inverter circuit 22.

Next, a high frequency conversion device on which a high frequency conversion circuit is mounted will be described.
FIG. 2 is a high-frequency conversion device on which the high-frequency conversion circuit of FIG. 1 is mounted.

  The high frequency conversion device 200 includes a high frequency conversion circuit mounting substrate 201 on which the high frequency conversion circuit 10 is mounted.

  On this high-frequency conversion circuit mounting substrate 201, the electrolytic capacitor C1 and the high-frequency voltage dividing capacitor C11 are mounted upright with respect to the substrate surface, and are close to each other.

  Next, characteristics of the high-frequency voltage dividing capacitor C11 connected to the detection circuit 30 of the high-frequency conversion circuit 100 will be described.

  FIG. 3 is a graph of the capacitance change rate with respect to the temperature change of the high-frequency voltage dividing capacitor C11.

  The high-frequency voltage dividing capacitor C11 is a ceramic capacitor and has a characteristic that the capacitance at which the capacitor temperature rises greatly decreases. This characteristic has a capacitance change rate of + 30% to -80% with respect to the ambient temperature, which is generally called F characteristic in JIS and EIA standards.

Next, the operation of the high frequency conversion circuit 100 will be described.
When the electric power from the commercial power supply AC is supplied to the high frequency conversion circuit 100, the boost chopper circuit 12 operates and the boosted DC voltage is applied to the inverter circuit 22.

  A signal is generated from the switching control circuit 23 so that the switching elements Q2 and Q3 of the inverter circuit 22 are alternately turned on and off, and a high-frequency rectangular wave is generated between the connection point of the switching elements Q2 and Q3 and the low potential side of the electrolytic capacitor C1. Voltage is generated.

  This rectangular wave high frequency voltage is applied to the load Ld through the load circuit 21. The ballast choke L20, the load Ld, and the DC voltage component removing capacitor C20 are series resonant circuits, and high-frequency current flows through the load circuit 21 and the load Ld.

  High-frequency voltage dividing capacitors C10 and C11 are connected between the connection point of the ballast choke L20 and the load Ld and the reference potential line of the high-frequency conversion circuit 100, and both ends of the high-frequency voltage dividing capacitor C11 are high-frequency voltage dividing capacitors. A high-frequency voltage divided by the capacitances C10 and C11 is generated.

The divided high frequency voltages are diodes D10 and D11, a capacitor C12, and a resistor R12.
Thus, the peak-to-peak voltage (detection voltage V3) of the high frequency voltage applied to the high frequency voltage dividing capacitor C11 is input to the inverting input terminal of the comparator IC10.

  On the other hand, the reference voltage V4 divided by the DC control power source Vcc of the boost chopper control circuit 13 and the switching control circuit 23 and the resistors R10 and R11 is input to the non-inverting input terminal of the comparator IC10.

  The detection voltage V3 and the reference voltage V4 are compared by the comparator IC10. When the detection voltage V3 exceeds the reference voltage V4, the output of the comparator IC10 becomes Lo.

  Thus, when the high frequency voltage output from the inverter circuit 22 rises abnormally, the boost chopper control circuit 13 and the switching control circuit 23 are protected by the operation of the control circuit being stopped because the output of the comparator IC10 becomes Lo.

  Next, the operation when the electrolytic capacitor C1 abnormally generates heat due to the end of life or overvoltage application will be described.

  The electrolytic capacitor C1 and the high-frequency voltage dividing capacitor C11 connected to the detection circuit 30 are mounted close to each other on the high-frequency conversion circuit mounting substrate 201.

  As shown in FIG. 3, the high-frequency voltage dividing capacitor C11 has a characteristic that the capacitance is greatly reduced as the temperature rises.

  When the electrolytic capacitor C1 generates heat, the high-frequency voltage dividing capacitor C11 mounted in close proximity is also affected by the heat generation, and the temperature rises. For example, the temperature of the electrolytic capacitor C1 when the electrolytic capacitor is normal is 60 ° C. At this time, the temperature of the high-frequency voltage dividing capacitor C11 adjacent to the electrolytic capacitor C1 is also approximately 60 ° C.

  When the electrolytic capacitor C1 abnormally generates heat and the temperature reaches 100 ° C., the temperature of the adjacent high-frequency voltage dividing capacitor C11 also becomes approximately 100 ° C. Therefore, from the characteristic diagram of FIG. The capacitance decreases by about 20%, and the impedance at high frequency increases (high frequency impedance ZC11 = 1 / (2 × π × f × C11) of the high frequency voltage dividing capacitor C11).

  Since the high frequency voltage dividing capacitors C10 and C11 divide the high frequency voltage generated in the load circuit 21 and the load Ld to generate the detection voltage V3, when the impedance of the high frequency voltage dividing capacitor C11 increases, the detection voltage V3 also increases. It is clear that it will grow.

  The change in the detection voltage V3 is compared with the reference voltage V4 of the comparator IC10, and the capacitance ratio of the high frequency voltage dividing capacitors C10 and C11 is set so as to exceed the reference voltage V4 when the electrolytic capacitor C1 abnormally generates heat.

  When the detection voltage V3 exceeds the reference voltage V4, the output of the comparator IC10 becomes Lo, and the boost chopper control circuit 13 and the switching control circuit 23 are stopped.

  When the step-up chopper circuit 12 and the switching control circuit 23 are stopped, the step-up operation of the step-up chopper circuit 12 is stopped, the voltage applied to the electrolytic capacitor C1 is lowered, and the current flowing into the electrolytic capacitor C1 is also lowered at the same time. Heat generation of the electrolytic capacitor C1 is also reduced.

  In the present embodiment, when the output of the comparator IC10 becomes Lo, the operation of the control circuit of the boost chopper control circuit 13 and the switching control circuit 23 is stopped. However, the output of the comparator IC10 becomes Hi. Alternatively, the operation of the boost chopper control circuit 13 or the control circuit of the switching control circuit 23 may be stopped.

  In the present embodiment, the AC / DC conversion circuit 100 is configured by the rectifier circuit 11 and the step-up chopper circuit 12. However, in the high-frequency conversion circuit that does not use the step-up chopper circuit 12, the AC / DC conversion circuit 100 is provided. May be a circuit composed of a rectifier circuit and an electrolytic capacitor connected to the rectifier circuit, or a circuit composed of a rectifier circuit and a step-down chopper circuit.

  Thus, since the high frequency conversion circuit 100 supplies the high frequency AC voltage generated by the inverter circuit 22 to the load Ld, for example, when a fluorescent lamp is connected to the load Ld, the high frequency AC voltage is supplied to the fluorescent lamp. Can do.

  Moreover, although the case where the load Ld is detachably connected to the load circuit 21 has been described in the present embodiment, for example, the case where the load Ld is integrally connected to the high-frequency conversion circuit 100 may be used. .

Embodiment 2. FIG.
In the present embodiment, a switch SW1 is added to the high potential side of the electrolytic capacitor C1 of the high-frequency conversion circuit 100 shown in the first embodiment.

  In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 4 is a circuit diagram of the present embodiment.
The high-frequency conversion circuit 100a includes an AC / DC conversion circuit 10a, a power supply circuit 20, and a detection circuit 30.

  Since the operations of the power supply circuit 20 (the load circuit 21 and the inverter circuit 22) and the detection circuit 30 are the same as those in the first embodiment, the description thereof is omitted.

  The AC / DC converter circuit 10 a includes a rectifier circuit 11 and a boost chopper circuit 12 a connected to the rectifier circuit 11.

  The step-up chopper circuit 12a includes a switch SW1 connected between the connection point of the cathode of the switching diode D1, the output voltage detection resistor R1 and the switching element Q1, and the high potential side of the electrolytic capacitor C1, and the on / off state of the switch SW1. A switch control circuit 14 for controlling the turning-off, and the switch control circuit 14 is connected to the output of the comparator IC10 of the detection circuit 30.

  Next, an operation when the abnormal heat generation of the electrolytic capacitor C1 is detected by the detection circuit 30 and the output of the comparator IC10 becomes Lo will be described.

  Before the detection circuit 30 detects abnormal heat generation in the electrolytic capacitor C1, a signal for closing the switch SW1 is input from the switch control circuit 14 to the switch SW1.

  When the high frequency voltage dividing capacitor C11 of the detection circuit 30 detects abnormal heat generation of the electrolytic capacitor C1, the output of the comparator IC10 becomes Lo, and a signal for opening the switch SW1 is input from the switch control circuit 14 to the switch SW1.

  When the switch SW1 is opened, the voltage and current applied to the electrolytic capacitor C1 are cut off, and the circuit operations of the boost chopper control circuit 13 and the switching control circuit 23 are stopped.

  In the present embodiment, when the output of the comparator IC10 becomes Lo, the switch SW1 is opened, and the operation of the control circuit of the boost chopper control circuit 13 and the switching control circuit 23 is stopped. The operation of the step-up chopper control circuit 13 and the control circuit of the switching control circuit 23 may be stopped when the output of the signal becomes Hi.

  In the present embodiment, the detection voltage V3 and the reference voltage V4 are compared by the comparator IC10. However, when the detection voltage V3 becomes an abnormal value, the switch SW1 is opened, and the boost chopper control circuit 13 and the switching control are controlled. Any means may be used as long as the control operation of the circuit 23 is stopped.

Embodiment 3 FIG.
In the present embodiment, a switch is added in parallel with the electrolytic capacitor C1 of the high-frequency conversion circuit 100 shown in the first embodiment, and a current fuse is added to the input side of the rectifier circuit 11.

  In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

FIG. 5 is a circuit diagram of the present embodiment.
The high-frequency conversion circuit 100b includes an AC / DC conversion circuit 10b, a power supply circuit 20, and a detection circuit 30.

  Since the operations of the power supply circuit 20 (the load circuit 21 and the inverter circuit 22) and the detection circuit 30 are the same as those in the first embodiment, the description thereof is omitted.

  The AC / DC converter circuit 10 b includes a rectifier circuit 11 and a boost chopper circuit 12 b connected to the rectifier circuit 11.

  The step-up chopper circuit 12b includes a switch SW2 connected in parallel with the electrolytic capacitor C1 and a switch control circuit 15 for controlling on / off of the switch SW2. The switch control circuit 15 is a circuit of the comparator IC10 of the detection circuit 30. Connected to the output.

  Next, an operation when the abnormal heat generation of the electrolytic capacitor C1 is detected by the detection circuit 30 and the output of the comparator IC10 becomes Lo will be described.

  Before the high frequency voltage dividing capacitor C11 of the detection circuit 30 detects abnormal heat generation of the electrolytic capacitor C1, a signal for opening the switch SW2 is input from the switch control circuit 15 to the switch SW2.

  When the high-frequency voltage dividing capacitor C11 of the detection circuit 30 detects abnormal heat generation of the electrolytic capacitor C1, the output of the comparator IC10 becomes Lo, and a signal for closing the switch SW2 is input from the switch control circuit 15 to the switch SW2.

  When the switch SW2 is closed, the electrolytic capacitor C1 is substantially short-circuited, so that a large current flows through the current fuse F of the rectifier circuit 11 and melts, so that no current is supplied to the circuit of the electronic device.

  In this embodiment, when the output of the comparator IC10 becomes Lo, the switch SW2 is closed and the current fuse F of the rectifier circuit 1 is blown. However, the output of the comparator IC10 becomes Hi. The current fuse F may sometimes be blown.

  In the present embodiment, the detection voltage V3 and the reference voltage V4 are compared by the comparator IC10. When the detection voltage V3 becomes an abnormal value, the switch SW2 is closed and the current fuse F is blown. Any means can be used.

Embodiment 4 FIG.
In the present embodiment, the configuration of the load circuit 21 shown in the first embodiment is different.

  In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 6 is a circuit diagram of the present embodiment.

  The high frequency conversion circuit 100 c includes an AC / DC conversion circuit 10, a power supply circuit 20 a, and a detection circuit 30.

  The power supply circuit 20 a includes a load circuit 21 a and an inverter circuit 22.

  Since the operations of the AC / DC converter circuit 10, the inverter circuit 22, and the detection circuit 30 are the same as those of the first embodiment, the description thereof is omitted.

  The load circuit 21a is connected to the ballast choke L20 connected to the inverter circuit 22 and the DC voltage component removing capacitor C20, and is connected between the ballast choke L20 and the DC voltage component removing capacitor C20 to rectify the high-frequency AC voltage. A bridge DB2 and a smoothing capacitor C21 that smoothes the rectified current are provided.

  Thus, since the load circuit 21a converts the high-frequency AC voltage generated by the inverter circuit 22 by the diode bridge DB2 and the smoothing capacitor C21 into a DC current, the DC current can be supplied to the load Ld. For example, the load Ld When an LED (light emitting diode) is connected to the LED, a direct current can be supplied to the LED.

  In the present embodiment, the case where the load Ld connected to the high frequency conversion circuit is detachably attached has been described, but the load Ld may be integrally connected to the high frequency conversion circuit. Good.

  10, 10a, 10b AC / DC converter circuit, 11 Rectifier circuit, 12, 12a, 12b Boost chopper circuit, 13 Boost chopper control circuit, 14, 15 Switch control circuit, 20, 20a Power supply circuit, 21, 21a Load circuit, 22 Inverter Circuit, 23 switching control circuit, 30 detection circuit, 100, 100a to 100c high frequency conversion circuit, 200 high frequency conversion device, 201 high frequency conversion circuit mounting board, AC commercial power supply, T1 transformer, Q1 to Q3 switching element, Ld load, R1, R2 output voltage detection resistor, R4, R5 pulsating voltage detection resistor, R6 current detection resistor, R10 to R12 resistor, C1 electrolytic capacitor, C10, C11 high frequency voltage dividing capacitor, C12 capacitor, C20 DC voltage component removing capacitor, C21 smoothing Conden S, L20 Ballast choke, DB1, DB2 Diode bridge, D1 switching diode, D10, D11 diode, IC10 comparator, F current fuse, SW1, SW2 switch.

Claims (7)

  An AC / DC converter circuit having a rectifier circuit for rectifying an AC voltage and an electrolytic capacitor for smoothing the voltage rectified by the rectifier circuit, and connected to the AC / DC converter circuit, the DC voltage smoothed by the electrolytic capacitor is converted into a high-frequency AC voltage. An inverter circuit, a load circuit to which a high-frequency AC voltage output from the inverter circuit is applied, and a high-frequency voltage voltage dividing capacitor that detects the high-frequency AC voltage of the load circuit, the voltage of the high-frequency voltage voltage dividing capacitor A detection circuit that outputs a detection signal according to a value, and the high-frequency voltage dividing capacitor of the detection circuit changes capacitance according to a temperature change, and is disposed close to the electrolytic capacitor. A characteristic electrolytic capacitor abnormality detection device.   2. The electrolytic capacitor abnormality detection device according to claim 1, wherein a detection signal output from the detection circuit is input to the inverter circuit.   A rectifier circuit that rectifies an AC voltage and an AC / DC converter circuit having an electrolytic capacitor that smoothes the voltage rectified by the rectifier circuit, and a load is connected, and a high-frequency alternating current is generated from the DC voltage smoothed by the electrolytic capacitor, A power supply circuit that converts the voltage according to the load and applies the converted voltage to the load; and a high-frequency voltage dividing capacitor that detects a high-frequency alternating current generated by the power supply circuit. A detection circuit that outputs a detection signal according to a voltage value of the voltage dividing capacitor, and the high frequency voltage dividing capacitor of the detection circuit changes a capacitance according to a temperature change, and the electrolytic capacitor An apparatus for detecting an abnormality in an electrolytic capacitor, characterized in that it is disposed close to the capacitor.   4. The switch according to claim 1, wherein a switch is connected in series to the electrolytic capacitor, and the switch that is normally closed is opened by a detection signal of the detection circuit. 5. Electrolytic capacitor abnormality detection device.   A switch is connected in parallel with the electrolytic capacitor, and a current fuse is provided at a position on the power supply side of the electrolytic capacitor, and the switch that is normally open is closed by a detection signal of the detection circuit. The electrolytic capacitor abnormality detection device according to any one of claims 1 to 3.   6. A chopper circuit for boosting or stepping down a DC voltage is connected to the AC / DC converter circuit, and a detection signal output from the detection circuit is input to a control circuit of the chopper circuit. Electrolytic capacitor abnormality detection device. An abnormality detection device for an electrolytic capacitor according to any one of claims 1 to 6,
An instrument body for housing the electrolytic capacitor abnormality detection device;
The load of the abnormality detection device for the electrolytic capacitor includes at least a light source.

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