JP2018057178A - Electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical apparatus capable of suppressing damage to an element due to a high voltage and also suppressing an increase in a product size.SOLUTION: A power tool 1 includes: a motor 6; an inverter circuit 47 that includes switching elements Q1 to Q6 for supplying a driving current to the motor 6; an arithmetic unit (control unit) 21 that controls the switching elements Q1 to Q6; a first power supply circuit 10 that converts an AC power into a DC power for driving the motor 6; and a second power supply circuit 20 that converts AC power into a DC power for operating the arithmetic unit 21. The withstand voltage of a predetermined element constituting the second power supply circuit 20 is higher than the withstand voltage of a predetermined element constituting the first power supply circuit 10. When an input AC voltage exceeds a predetermined value, a voltage input path to the first power supply circuit 10 is interrupted.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electric device such as an electric tool including a motor.

  Patent Document 1 below discloses a configuration in an AC-driven electric tool in which power from an AC power source is converted into DC power by a power supply circuit and supplied to a motor and a control circuit.

Japanese Patent Laying-Open No. 2015-208784

  For example, when the AC power supply is a generator, the input voltage may be higher than expected. As a result, a voltage exceeding the withstand voltage is applied to the elements constituting the power supply circuit, and the elements are damaged. Here, when an element having a high withstand voltage that allows an input voltage exceeding the assumption is used, the element size increases and the product size increases.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electric device capable of suppressing an increase in product size while suppressing damage to an element due to a high voltage.

One embodiment of the present invention is an electric device. This electrical equipment
A motor,
A switching element for supplying a driving current to the motor;
A control unit for controlling the switching element;
A first power supply circuit for converting alternating current power into direct current power for driving the motor;
A second power supply circuit that converts AC power into DC power for operation of the control unit,
The withstand voltage of the predetermined element constituting the second power supply circuit is higher than the withstand voltage of the predetermined element constituting the first power supply circuit.

Another embodiment of the present invention is an electrical device. This electrical equipment
A motor,
A switching element for supplying a driving current to the motor;
A control unit for controlling the switching element;
A first power supply circuit for converting alternating current power into direct current power for driving the motor;
A second power supply circuit that converts AC power into DC power for operation of the control unit,
When the input AC voltage exceeds a predetermined value, the voltage input path to the first power supply circuit is cut off, while the second power supply circuit continues to operate and maintains the control unit in an activated state. And

  When the input AC voltage exceeds the withstand voltage of a predetermined element constituting the first power supply circuit, the voltage input path to the first power supply circuit is interrupted, while the second power supply circuit continues to operate. The control unit may be maintained in an activated state.

  The withstand voltage of the predetermined element constituting the second power supply circuit may be higher than the withstand voltage of the predetermined element constituting the first power supply circuit.

  The allowable current or capacity of a predetermined element constituting the second power supply circuit may be smaller than the allowable current or capacity of a predetermined element constituting the first power supply circuit.

Opening and closing means for switching between conduction and interruption of the voltage input path to the first power supply circuit;
Voltage detecting means for detecting the input AC voltage,
The control unit may perform control to switch the opening / closing means to cutoff when a detected voltage value by the voltage detecting means exceeds a predetermined value.

  The control unit may perform control to switch the opening / closing means to shut-off when a detected voltage value by the voltage detecting means exceeds a withstand voltage of a predetermined element constituting the first power supply circuit.

Opening and closing means for switching between conduction and interruption of the voltage input path to the first power supply circuit;
A voltage comparison circuit different from the control unit, wherein the output is switched according to whether or not the input AC voltage exceeds a predetermined value, and
When the input AC voltage exceeds a predetermined value, the opening / closing means may be switched to shut-off by the output of the voltage comparison circuit regardless of the control of the control unit.

  When the input AC voltage exceeds the withstand voltage of a predetermined element constituting the first power supply circuit, the opening / closing means may be switched off by the output of the voltage comparison circuit.

Each of the first and second power supply circuits includes a varistor and an electrolytic capacitor,
The withstand voltages of the varistor and the electrolytic capacitor of the second power supply circuit may be higher than the withstand voltages of the varistor and the electrolytic capacitor of the first power supply circuit.

  The withstand voltage of the predetermined element constituting the second power supply circuit may be 1.5 times or more of the withstand voltage of the predetermined element constituting the first power supply circuit.

  You may provide the alerting | reporting means to alert | report when the input alternating voltage exceeds predetermined value.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical equipment which can also suppress the enlargement of a product size can be provided, suppressing the damage of the element by a high voltage.

1 is a side sectional view of a power tool 1 according to an embodiment of the present invention. The circuit diagram of the electric tool 1. FIG. 4 is a time chart showing an example of the operation of the electric power tool 1. 4 is a control flowchart of the electric power tool 1. The circuit diagram of the electric tool which concerns on a comparative example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  FIG. 1 is a side sectional view of a power tool 1 according to an embodiment of the present invention. With reference to FIG. 1, each direction is defined in the up / down and front / rear directions. The electric power tool 1 is an impact wrench here. In the electric power tool 1, the housing 2 includes a cylindrical body portion 2a, a handle portion 2b extending downward from a substantially central portion of the body portion 2a, and a storage portion 2c provided at a lower end portion of the handle portion 2b. . A motor 6, a speed reduction mechanism 3, a spindle 4, a hammer 5, and an anvil 8 are provided in the body portion 2 a in order from the rear.

  The motor 6 is a brushless motor and includes an output shaft 6a, a rotor 6b, and a stator. The rotor 6b includes a rotor magnet 6e, and is integrally provided around the output shaft 6a. The stator includes a stator core 6c held by the body portion 2a, and a stator coil 6d provided on the stator core 6c (U, V, and W windings shown in FIG. 2).

  The speed reduction mechanism 3 is a planetary gear mechanism, for example, and reduces the rotation of the motor 6 and transmits it to the spindle 4. The hammer 5 is rotated by the spindle 4, and the hammer 5 gives a rotating impact force to the anvil 8. A tip tool holding portion 8a is provided at the tip portion of the anvil 8, and a tip tool (not shown) such as a socket held by the tip tool holding portion 8a is rotationally driven by a rotating impact force. Since the configuration and operation from the rotation of the motor 6 to the generation of the rotational impact force are well known, further detailed description is omitted.

  A main board 53 is provided below the motor 6 in the body portion 2a. An LED 27 as a notification unit is provided at the upper end of the handle portion 2b. The LED 27 is, for example, a white LED. A trigger switch (operation switch) 7 is provided below the LED 27 in the handle portion 2b. The trigger switch 7 is a switch for the user to control power supply to the motor 6. A relay 51 as an opening / closing means is provided at the inner lower portion of the handle portion 2b. A power cord 9 for connecting to an external AC power supply 50 (FIG. 2) extends from the lower end of the storage portion 2c. A filter substrate 52 is provided in the storage portion 2c.

  FIG. 2 is a circuit diagram of the electric power tool 1. In FIG. 2, an AC power source 50 is a commercial power source or a generator. Some generators can adjust the output voltage, and a voltage exceeding the rated voltage of the electric power tool 1 may be output. The circuit of FIG. 2 is intended to suppress an increase in product size while suppressing element destruction even when a voltage exceeding the rated voltage is input.

  In FIG. 2, one end of a fuse Fin is connected to the AC power supply 50. The first power supply circuit 10 is connected to the other end of the fuse Fin via the relay 51, and the second power supply circuit 20 is connected in parallel with the relay 51 and the first power supply circuit 10. As described later, the relay 51 is controlled to be turned on / off by an output voltage of the comparator (voltage comparison circuit) 28 or a control signal from the calculation unit 21. The diode D3 is provided to consume inductive energy of the coil of the relay 51 after the switching element Q7 is turned off.

  The first power supply circuit 10 includes a varistor Z1, a pattern fuse F1, a capacitor C1, a resistor R1, a choke coil L1, a diode bridge 15, and an electrolytic capacitor C2. The fuse Fin, the varistor Z1, the pattern fuse F1, the capacitor C1, the resistor R1, and the choke coil L1 form a filter circuit, and are provided on the filter substrate 52 shown in FIG. The fuse Fin is for protection when the switching elements Q1 to Q6 are short-circuited. The varistor Z1 is for absorbing surge voltage. The pattern fuse F1 has a role of preventing a short circuit between lines when the varistor Z1 is activated. The capacitor C1 and the choke coil L1 are for removing noise between lines. The resistor R1 is a discharge resistor of the capacitor C1. The diode bridge 15 as a rectifier circuit performs full-wave rectification on the output voltage from the filter circuit described above and converts it into direct current. The electrolytic capacitor C <b> 2 is for surge absorption and is provided between the output terminals of the diode bridge 15.

  The inverter circuit 47 includes switching elements Q1 to Q6 such as IGBTs and FETs connected in a three-phase bridge, and switches the output voltage of the first power supply circuit 10 according to the control of the arithmetic unit 21 as a control unit. A drive current is supplied to the coil 6d (each winding of U, V, and W). The resistor Rs is provided in the current path of the motor 6. The computing unit 21 detects the current of the motor 6 based on the voltage across the resistor Rs. In addition, the calculation unit 21 detects the rotational position of the rotor 6 b based on the output voltages of the plurality of Hall elements (magnetic sensors) 42. The computing unit 21 performs switching control (for example, PWM control) on the switching elements Q <b> 1 to Q <b> 6 according to the operation of the trigger switch 7.

  The second power supply circuit 20 includes a varistor Z2, a pattern fuse F2, a diode bridge 25, an electrolytic capacitor C3, resistors R4 and R5, an IPD circuit 22, and a regulator 26. The varistor Z2 is for absorbing surge voltage. The pattern fuse F2 has a role of preventing a short circuit between lines when the varistor Z2 is activated. The diode bridge 25 as a rectifier circuit performs full-wave rectification on the output voltage of the AC power supply 50 and converts it to DC. The electrolytic capacitor C3 is for surge absorption. The resistors R4 and R5 are for voltage detection in the arithmetic unit 21 and the relay control circuit 54, and are connected in series between the output terminals of the diode bridge 25. The IPD circuit 22 is a circuit constituted by an IPD element, a capacitor, and the like which are intelligent power devices, and the voltage rectified and smoothed by the diode bridge 25 and the electrolytic capacitor C3 is stepped down to, for example, about 18V. DC-DC switching power supply circuit. The IPD circuit 22 is an integrated circuit and has an advantage of low power consumption and energy saving. The output voltage of the IPD circuit 22 is further stepped down to, for example, about 5 V by the regulator 26 and is supplied to the arithmetic unit 21 as an operating voltage (power supply voltage Vcc).

  The relay control circuit 54 includes a comparator 28 and an N-channel type switching element Q7 such as IGBT or FET. A voltage obtained by dividing Vcc (5 V) by resistors R2 and R3 is input to the non-inverting input terminal of the comparator 28. A voltage obtained by dividing the output voltage of the diode bridge 25 by the resistors R4 and R5 is input to the inverting input terminal of the comparator 28. The output terminal of the comparator 28 is connected to the cathode of the diode D2. The anode of the diode D2 is connected to the gate (control terminal) of the switching element Q7 and the cathode of the diode D1. The anode of the diode D1 is connected to the arithmetic unit 21 via the resistor R6. The drain of the switching element Q7 is connected to one end of the parallel connection of the relay 51 and the diode D3. The other end of the parallel connection of the relay 51 and the diode D3 is connected to the power supply line (Vcc). The source of the switching element Q7 is grounded.

  The diode bridge 15, the electrolytic capacitor C2, the resistor Rs, the inverter circuit 47, the calculation unit (microcomputer) 21, the second power supply circuit 20, and the relay control circuit 54 shown in FIG. 2 are provided on the main board 53 in FIG.

  In FIG. 2, each element in the standard withstand voltage circuit 30 has a withstand voltage that matches the rated voltage of the power tool 1, and an allowable current and a capacity that also match the rated current of the power tool 1. On the other hand, each element in the high withstand voltage circuit 60 has a withstand voltage higher than the rated voltage of the electric power tool 1, and an allowable current and capacity are smaller than the rated current of the electric power tool 1. Specifically, the varistor Z2 has a higher withstand voltage and a smaller allowable current than the varistor Z1. Further, the electrolytic capacitor C3 has a higher withstand voltage and a smaller capacity than the electrolytic capacitor C2. The diode bridge 25 has a higher withstand voltage and a smaller allowable current than the diode bridge 15. For example, the varistor Z1 is 510V, the diode bridge 15 is 600V (allowable current 35A), the electrolytic capacitor C2 is 450V (capacity 68μF), the varistor Z2 is 1000V, the diode bridge 25 is 1000V (allowable current 1A), The electrolytic capacitor C3 is 800V (capacity 10 μF). That is, the withstand voltage of each element in the high withstand voltage circuit 60 is 1.5 times or more the withstand voltage of each element in the standard withstand voltage circuit 30.

  AC power supplied from the AC power supply 50 is converted into DC power for driving the motor 6 by the first power supply circuit 10 and supplied to the motor 6 via the inverter circuit 47. On the other hand, AC power supplied from the AC power supply 50 is converted by the second power supply circuit 20 into DC power for operation of the computing unit 21. When the operating voltage Vcc is supplied, the arithmetic unit 21 is started, the gate voltage of the switching element Q7 is set to a high level, the relay 51 is turned on, and the inverter circuit 47 is switched according to the operation of the trigger switch 7. Q1 to Q6 are switching-controlled. When the input voltage from the AC power supply 50 exceeds a predetermined value, the calculation unit 21 sets the gate voltage of the switching element Q7 to a low level to turn off the relay 51 (off state), and the voltage input path to the first power supply circuit 10 Shut off the (current input path). Thereby, application of a voltage exceeding a predetermined value to each element of the first power supply circuit 10 can be cut off. Note that the input voltage from the AC power supply 50 is specified by a voltage obtained by dividing the output voltage of the diode bridge 25 by the resistors R4 and R5. Even if the relay 51 is cut off, the second power supply circuit 20 continues to operate, and the computing unit 21 is maintained in the activated state. The arithmetic unit 21 controls the voltage input path to the first power supply circuit 10 while controlling the gate voltage of the switching element Q7 to low level, that is, when the input voltage from the AC power supply 50 exceeds a predetermined value. While shutting off, the user is notified by blinking the LED 27 or the like.

  The comparator 28 is provided in order to put the relay 51 in a disconnected state regardless of the control of the calculation unit 21. When the input voltage from the AC power supply 50 exceeds a predetermined value, the comparator 28 divides the output voltage of the diode bridge 25 by the resistors R4 and R5, and divides Vcc (5V) by the resistors R2 and R3. When the voltage exceeds the output voltage, the output voltage is switched from the high level to the low level. When the output voltage of the comparator 28 becomes low level, the gate voltage of the switching element Q7 becomes low level regardless of the control of the calculation unit 21 (regardless of the voltage level between the resistor R6 and the calculation unit 21), and the relay 51 is turned on. The cut-off state is established, and the voltage input path to the first power supply circuit 10 is cut off. Thereby, the voltage input path to the first power supply circuit 10 can be cut off without waiting for the control by the arithmetic unit 21, and the application time of the voltage exceeding the predetermined value to each element of the first power supply circuit 10 can be shortened.

  FIG. 3 is a time chart showing an example of the operation of the electric power tool 1. In FIG. 3, “AC input voltage” indicates an effective value of the AC voltage input from the AC power supply 50. The voltage value of 280 V is an example of a threshold value (predetermined value) for switching the relay 51 on and off. The “microcomputer state” indicates whether or not the calculation unit 21 is activated (on or off). The “relay control signal” indicates the level (high or low) of the signal output from the arithmetic unit 21 through the signal line connected to the gate of the switching element Q7. The “comparator output signal” indicates the level (high or low) of the output signal of the comparator 28. The “relay state” indicates a state (ON or OFF) in which the relay 51 is turned on or off. “LED” indicates the lighting state (ON or OFF) of the LED 27. The threshold value (predetermined value) may be a withstand voltage value of an element in the standard withstand voltage circuit 30 (for example, 510V of the varistor Z1), and may be set to a value that does not damage the element in the standard withstand voltage circuit 30.

  When the power cord 9 (FIG. 1) is connected to the AC power supply 50 (FIG. 2) at time t1, the operating voltage Vcc is supplied to the computing unit 21, and the computing unit 21 is activated. At time t1, since the input voltage from AC power supply 50 exceeds 280V, operation unit 21 sets the relay control signal to a low level and does not turn on switching element Q7. The output voltage of the comparator 28 is at a low level, and the switching element Q7 is not turned on. Therefore, the relay 51 is off (the voltage input path to the first power supply circuit 10 is cut off). The calculation unit 21 blinks the LED 27 and notifies the user that the power tool 1 cannot be used because the input voltage exceeds a predetermined value. Thereafter, for example, when the AC power supply 50 is a generator and the user adjusts the output voltage of the AC power supply 50 and the output voltage becomes 280 V or less at time t2, the arithmetic unit 21 changes the relay control signal from low level to high level. Switch to. Further, the output voltage of the comparator 28 is switched from the low level to the high level. As a result, the switching element Q7 is turned on, the relay 51 is turned on (the voltage input path to the first power supply circuit 10 is turned on), the first power supply circuit 10 is activated, and the power tool 1 can be operated. The calculation unit 21 stops the blinking of the LED 27 and turns it off. Thereafter, when the output voltage of the AC power supply 50 exceeds 280 V at time t3, the arithmetic unit 21 sets the relay control signal to a low level, and the output voltage of the comparator 28 becomes a low level. As a result, the relay 51 is turned off (the voltage input path to the first power supply circuit 10 is cut off). The calculation unit 21 blinks the LED 27 and notifies the user that the power tool 1 cannot be used because the input voltage exceeds a predetermined value. When the relay control signal from the arithmetic unit 21 is high level and the output voltage of the comparator 28 is low level, the gate voltage of the switching element Q7 is pulled down by the resistor R6, the switching element Q7 is off, and the relay 51 is off (first). 1) The voltage input path to the power supply circuit 10 is cut off. When the relay control signal from the calculation unit 21 is at a low level and the output voltage of the comparator 28 is at a high level, the gate voltage of the switching element Q7 is at a low level and the switching element Q7 is turned off. That is, the switching element Q7 is turned on only when both the relay control signal from the computing unit 21 and the output voltage of the comparator 28 are at a high level. In other words, when at least one of the relay control signal from the calculation unit 21 and the output voltage of the comparator 28 is at a low level, the switching element Q7 is turned off.

  FIG. 4 is a control flowchart of the power tool 1. When the user connects the power cord 9 to the AC power supply 50 (S1), the calculation unit 21 checks whether or not the input voltage from the AC power supply 50 is equal to or lower than a threshold value (predetermined value) (S2). When the input voltage from the AC power supply 50 is equal to or lower than the threshold value (Yes in S2), the calculation unit 21 turns off the LED 27 (S3). When the trigger switch 7 is subsequently turned on (Yes in S4), the arithmetic unit 21 drives the motor 6 to rotate by switching control of the inverter circuit 47 (S5). When the trigger switch 7 is off (No in S4), the calculation unit 21 stops the motor 6 (S6). When the input voltage from the AC power supply 50 exceeds the threshold value (No in S2), the computing unit 21 sets the relay control signal to a low level to turn off the switching element Q7 and turn off the relay 51, whereby the first power supply The voltage input to the circuit 10 is cut off (S7), and the LED 27 is controlled to blink (S8).

  According to the present embodiment, the following effects can be achieved.

(1) The first power supply circuit 10 that outputs DC power for driving the motor 6 and the second power supply circuit 20 that outputs DC power for the control system are separated, and each element of the first power supply circuit 10 is an electric tool. The rated voltage of 1 and the withstand voltage according to the rated current and the allowable current are set so that each element of the second power supply circuit 20 has a higher withstand voltage than the rated voltage of the power tool 1 (each element of the first power supply circuit 10). On the other hand, in order to make the allowable current smaller than the rated current of the electric power tool 1 (for example, in the case of a diode bridge), the second power supply circuit 20 Compared with the case where the withstand voltage of each element is made as high as possible, although the number of elements increases, the total size of the elements can be reduced and the product size can be reduced. That is, in the case of the configuration in which the DC power for driving the motor 6 and the DC power for the control system are output by one power supply circuit as in the comparative example shown in FIG. 5, even if a voltage exceeding the rated voltage is input, it is not damaged. If the withstand voltage and a large allowable current for the motor drive system are used, the size of elements such as the varistor Z1, the electrolytic capacitor C2, and the diode bridge 15 constituting the power supply circuit becomes very large, resulting in an increase in product size. However, according to the present embodiment, such a problem can be preferably solved.

(2) When the input voltage from the AC power supply 50 exceeds a predetermined value, the relay 51 is turned off and the voltage input to the first power supply circuit 10 is cut off, so that the withstand voltage to each element of the first power supply circuit 10 is exceeded. Application of a high voltage can be cut off, and damage to each element of the first power supply circuit 10 can be suppressed. Here, even if the relay 51 is cut off, the second power supply circuit 20 continues to operate, and the computing unit 21 is maintained in the activated state, so that the user can be notified by the blinking light of the LED 27. The person can quickly detect the abnormality and take measures such as reducing the output voltage of the AC power supply 50.

(3) Since the switching element Q7 can be turned off only by the output voltage of the comparator 28 and the relay 51 can be cut off regardless of the control of the calculation unit 21, the first power supply when the input voltage from the AC power supply 50 exceeds a predetermined value The voltage input to the circuit 10 can be quickly cut off.

(4) Only when both the relay control signal from the calculation unit 21 and the output voltage of the comparator 28 are at a high level, the switching element Q7 is turned on and the relay 51 is turned on (the voltage from the AC power supply 50 to the first power supply circuit 10). Is excellent in terms of fail-safe.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  The notification that the input voltage from the AC power supply 50 exceeds the predetermined value is not limited to the blinking of the LED 27, and may be a light emission form (lighting or the like) other than blinking, or may be a sound notification. Good. Further, when the input voltage from the AC power supply 50 is close to a predetermined value even if it is equal to or lower than a predetermined value, the LED 27 may be slowly blinked. In this case, when the input voltage exceeds a predetermined value, it may be blinked quickly. In the embodiment, “direct current” is not limited to a constant value, and may include pulsation as long as the positive and negative voltages and the current direction are constant.

  The opening / closing means is not limited to the relay 51 illustrated in the embodiment, and may be a switching element such as a triac. In the embodiment, the impact wrench is exemplified as the electric device, but the present invention is also effective for an electric device including an electric tool other than the impact wrench and a motor other than the electric tool.

DESCRIPTION OF SYMBOLS 1 Electric tool, 2 Housing, 2a Body part, 2b Handle part, 2c Storage part, 3 Reduction mechanism, 4 Spindle, 5 Hammer, 6 Motor, 6a Output shaft, 6b Rotor, 6c Stator core, 6d Stator coil, 6e Rotor magnet, 7 trigger switch (operation switch), 8 anvil, 8a tip tool holding unit, 9 power cord, 10 first power circuit, 15 diode bridge, 20 second power circuit, 21 calculation unit (control unit), 22 IPD circuit, 26 Regulator, 27 LED, 28 Comparator (voltage comparison circuit), 30 Standard withstand voltage circuit, 50 AC power supply, 51 Relay (opening / closing means), 52 Filter board, 53 Main board, 54 Relay control circuit, 60 High withstand voltage circuit

Claims (12)

A motor,
A switching element for supplying a driving current to the motor;
A control unit for controlling the switching element;
A first power supply circuit for converting alternating current power into direct current power for driving the motor;
A second power supply circuit that converts AC power into DC power for operation of the control unit,
An electrical apparatus, wherein a withstand voltage of a predetermined element constituting the second power supply circuit is higher than a withstand voltage of a predetermined element constituting the first power supply circuit. A motor,
A switching element for supplying a driving current to the motor;
A control unit for controlling the switching element;
A first power supply circuit for converting alternating current power into direct current power for driving the motor;
A second power supply circuit that converts AC power into DC power for operation of the control unit,
When the input AC voltage exceeds a predetermined value, the voltage input path to the first power supply circuit is cut off, while the second power supply circuit continues to operate and maintains the control unit in an activated state. And electrical equipment.   When the input AC voltage exceeds the withstand voltage of a predetermined element constituting the first power supply circuit, the voltage input path to the first power supply circuit is interrupted, while the second power supply circuit continues to operate. The electric device according to claim 2, wherein the control unit is maintained in an activated state.   The electric device according to claim 2 or 3, wherein a withstand voltage of a predetermined element constituting the second power supply circuit is higher than a withstand voltage of a predetermined element constituting the first power supply circuit.   5. The allowable current or capacity of a predetermined element constituting the second power supply circuit is smaller than an allowable current or capacity of a predetermined element constituting the first power supply circuit. An electrical device according to any one of the above. Opening and closing means for switching between conduction and interruption of the voltage input path to the first power supply circuit;
Voltage detecting means for detecting the input AC voltage,
6. The electricity according to claim 1, wherein the control unit performs control to switch the opening / closing means to cutoff when a voltage value detected by the voltage detection means exceeds a predetermined value. machine.   The said control part performs control which switches the said switching means to interruption | blocking, if the detection voltage value by the said voltage detection means exceeds the withstand voltage of the predetermined | prescribed element which comprises the said 1st power supply circuit. 6. The electric device according to 6. Opening and closing means for switching between conduction and interruption of the voltage input path to the first power supply circuit;
A voltage comparison circuit different from the control unit, wherein the output is switched according to whether or not the input AC voltage exceeds a predetermined value, and
8. The switch according to claim 1, wherein when the input AC voltage exceeds a predetermined value, the open / close means is switched to shut-off regardless of the control of the control unit by the output of the voltage comparison circuit. 9. Electrical equipment as described in the paragraph.   9. The switching means is switched off according to an output of the voltage comparison circuit when the input AC voltage exceeds a withstand voltage of a predetermined element constituting the first power supply circuit. Electrical equipment. Each of the first and second power supply circuits includes a varistor and an electrolytic capacitor,
The withstand voltage of each varistor and electrolytic capacitor of the second power supply circuit is higher than each withstand voltage of the varistor and electrolytic capacitor of the first power supply circuit. The electrical equipment described.   The withstand voltage of the predetermined element constituting the second power supply circuit is 1.5 times or more of the withstand voltage of the predetermined element constituting the first power supply circuit. The electrical device according to any one of the above.   The electric device according to any one of claims 1 to 11, further comprising notification means for notifying that an input AC voltage exceeds a predetermined value.

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