Washing machine and control method thereof

Abstract

The invention provides a washing machine and a control method thereof. The invention provides a washing machine capable of suppressing inrush current flowing at the moment of starting to supply driving power to a load from an AC power supply. The washing machine includes: a load that performs an operation related to washing; and a power supply control unit that controls the supply of drive power from the AC power supply to the load. The power supply control unit includes: a first rectifying and smoothing circuit connected between the AC power supply and the load and including a first smoothing capacitor; a first switching circuit that switches ON / OFF of a first connection path that connects the AC power supply and the first rectifying and smoothing circuit; a phase detection circuit that detects the phase of the AC voltage output by the AC power supply; and a first control circuit. The first control circuit causes the first switching circuit to conduct the first connection path at a zero-crossing timing of the AC voltage on the basis of the phase detected by the phase detection circuit.

Description

Technical Field

[0001] The present disclosure relates to a washing machine and a control method thereof. Background Art

[0002] BACKGROUND OF THE INVENTION A washing machine related to the background art is disclosed in Patent Document 1, for example. This washing machine is equipped with a main microcomputer ("microcomputer" in this disclosure means a microcontroller), an operating load, a submicrocomputer, a communication unit, a power supply device, and a power supply control unit. In the communication mode in which the communication unit communicates, the power supply voltage is always supplied from the power supply device to the submicrocomputer, the communication unit, and the power supply control unit. In the communication mode and the power saving mode in which the operating load is not controlled, the power supply control unit stops the supply of the power supply voltage from the power supply device to the main microcomputer and the operating load.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-159989 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] According to the washing machine disclosed in Patent Document 1, no countermeasures are taken against the inrush current that flows at the moment when the power supply device starts supplying the power supply voltage to the operating load.

[0008] An object of the present disclosure is to provide a washing machine and a control method thereof that can suppress an inrush current that flows at the moment when driving power starts to be supplied from an AC power supply to a load.

[0009] Solutions for solving problems

[0010] A washing machine according to one embodiment of the present disclosure includes: a load that performs actions related to washing; and a power supply control unit that controls the supply of driving power from an AC power supply to the load, wherein the power supply control unit has: a first rectification and smoothing circuit that is connected between the AC power supply and the load and includes a first smoothing capacitor; a first switching circuit that switches on or off a first connection path that connects the AC power supply to the first rectification and smoothing circuit; a phase detection circuit that detects the phase of the AC voltage output by the AC power supply; and a first control circuit that causes the first switching circuit to conduct the first connection path at a zero-crossing timing of the AC voltage based on the phase detected by the phase detection circuit.

[0011] Another embodiment of the present disclosure relates to a control method for a washing machine, wherein the washing machine includes: a load that performs actions related to washing; and a power supply control unit that controls the supply of driving power from an AC power supply to the load, the power supply control unit having: a first rectification and smoothing circuit that is connected between the AC power supply and the load and includes a first smoothing capacitor; a first switching circuit that switches on or off a first connection path that connects the AC power supply to the first rectification and smoothing circuit; a phase detection circuit that detects the phase of the AC voltage output by the AC power supply; and a first control circuit. In the control method for the washing machine, the first control circuit obtains the phase detected by the phase detection circuit, and based on the obtained phase, the first control circuit causes the first switching circuit to conduct the first connection path at a zero crossing timing of the AC voltage.

[0012] Effects of the Invention

[0013] According to the present disclosure, it is possible to suppress an inrush current that flows at the moment when the supply of driving power from the AC power supply to the load starts. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view showing the external appearance structure of a washing machine according to an embodiment of the present disclosure.

[0015] Figure 2 This is a diagram showing a simplified circuit configuration of a washing machine according to an embodiment.

[0016] Figure 3A This is a circuit diagram showing a circuit configuration example of a rectifying and smoothing circuit.

[0017] Figure 3B This is a circuit diagram showing another circuit configuration example of the rectifying and smoothing circuit.

[0018] Figure 3C This is a circuit diagram showing another circuit configuration example of the rectifying and smoothing circuit.

[0019] Figure 4 This is a flowchart showing a first operation executed by the washing machine according to the embodiment when the start button is pressed in the standby mode.

[0020] Figure 5 This is a timing chart showing a first operation performed by the washing machine according to the embodiment when the start button is pressed in the standby mode.

[0021] Figure 6 This is a flowchart showing a second operation performed by the washing machine according to the embodiment when the start button is pressed in the standby mode.

[0022] Figure 7 1 is a timing chart showing a second operation performed by the washing machine according to the embodiment when the start button is pressed in the standby mode.

[0023] Figure 8 This is a flowchart showing the operation performed by the washing machine according to the embodiment when washing is completed in the operation mode.

[0024] Figure 9 This is a diagram showing a simplified circuit configuration of a washing machine according to a first modification.

[0025] Figure 10 This is a flowchart showing a first operation performed by the washing machine according to the first modification when the switch of the washing machine is turned on while the power of the washing machine is off.

[0026] Figure 11 This is a flowchart showing a second operation performed by the washing machine according to the first modification when the switch of the washing machine is turned on while the power of the washing machine is off. DETAILED DESCRIPTION

[0027] (Insights that form the basis of this disclosure)

[0028] A washing machine according to the background art includes: a load such as a drive motor for rotating a washing tub or drum; a rectifying and smoothing circuit connected between an AC commercial power source and the load; a relay circuit for switching the connection path between the commercial power source and the rectifying and smoothing circuit; and a control circuit such as a microcomputer. The rectifying and smoothing circuit includes at least one diode and a smoothing capacitor with a large electrostatic capacitance.

[0029] When the user presses the power switch on the washing machine, the commercial power supply begins charging the smoothing capacitor via current flowing through a path through a current-limiting resistor. After a certain period of time, when the charged voltage of the smoothing capacitor rises above a threshold, the control circuit activates. The control circuit controls the relay circuit to connect the path between the commercial power supply and the rectifier-smoothing circuit. To minimize energy loss when driving the load, no current-limiting resistor is connected to this path.

[0030] When the relay circuit opens the connection path, a large inrush current flows due to the uncharged electrostatic capacity of the smoothing capacitor. Especially when the connection path is opened near the peak of the AC voltage waveform output by the commercial power supply, the inrush current becomes extremely large. This can cause excessive heating or failure of circuit components, potentially leading to malfunction of the washing machine.

[0031] To solve the above problem, the present inventors have found that the inrush current can be suppressed by aligning the timing of opening the connection path by the relay circuit with the zero-cross timing of the waveform of the AC voltage output by the commercial power supply. This has led to the present disclosure.

[0032] Next, each aspect of the present disclosure will be described.

[0033] A washing machine according to a first embodiment of the present disclosure includes: a load that performs actions related to washing; and a power supply control unit that controls the supply of driving power from an AC power supply to the load, wherein the power supply control unit has: a first rectifying and smoothing circuit that is connected between the AC power supply and the load and includes a first smoothing capacitor; a first switching circuit that switches on or off a first connection path that connects the AC power supply to the first rectifying and smoothing circuit; a phase detection circuit that detects the phase of the AC voltage output by the AC power supply; and a first control circuit that causes the first switching circuit to conduct the first connection path at a zero-crossing timing of the AC voltage based on the phase detected by the phase detection circuit.

[0034] According to the first embodiment, a phase detection circuit detects the phase of the AC voltage output by the AC power supply. Based on the phase detected by the phase detection circuit, the first control circuit causes the first switching circuit to conduct the first connection path at the timing of the AC voltage's zero crossing. This suppresses the inrush current that flows at the moment when drive power begins to be supplied from the AC power supply to the load.

[0035] The washing machine involved in the second embodiment of the present disclosure is preferably configured such that, in the first embodiment, the first control circuit inputs a control signal for causing the first switching circuit to turn on the first connection path to the first switching circuit, and the first control circuit controls the timing of outputting the control signal based on the phase detected by the phase detection circuit and the delay time from outputting the control signal to completion of conduction of the first connection path.

[0036] According to the second aspect, the first control circuit controls the timing of outputting the control signal based on the phase detected by the phase detection circuit and the delay time from outputting the control signal until the first connection path completes conduction. This allows the timing of the first connection path completing conduction to be precisely aligned with the zero-crossing timing of the AC voltage. As a result, inrush current can be more effectively suppressed.

[0037] The washing machine involved in the third aspect of the present disclosure is preferably, in the first or second aspect, further comprising: a second switching circuit that switches on or off a second connection path, the second connection path connecting the AC power supply and the first rectifying and smoothing circuit via a current-limiting resistor; and a voltage detection circuit that detects a charging voltage of the first smoothing capacitor, the first connection path connecting the AC power supply and the first rectifying and smoothing circuit in a manner bypassing the current-limiting resistor, the first control circuit starting charging the first smoothing capacitor from the AC power supply by causing the second switching circuit to turn on the second connection path, and the first control circuit causing the first switching circuit to turn on the first connection path at the zero-cross timing after the charging voltage becomes equal to or higher than a threshold value, based on the charging voltage detected by the voltage detection circuit and the phase detected by the phase detection circuit.

[0038] According to the third aspect, the first control circuit causes the first switching circuit to connect the first connection path at a zero-cross timing after the charge voltage of the first smoothing capacitor reaches or exceeds a threshold value. This reduces the uncharged capacitance of the first smoothing capacitor at the moment the first switching circuit connects the first connection path. Consequently, inrush current can be more effectively suppressed.

[0039] The washing machine involved in the fourth embodiment of the present invention is preferably, in the third embodiment, further provided with a second rectifying and smoothing circuit, wherein the second rectifying and smoothing circuit is connected between the AC power supply and the first control circuit and includes a second smoothing capacitor, the electrostatic capacitance of the second smoothing capacitor being smaller than the electrostatic capacitance of the first smoothing capacitor.

[0040] According to the fourth aspect, since the capacitance of the second smoothing capacitor included in the second rectifying and smoothing circuit is smaller than that of the first smoothing capacitor, leakage current from the second smoothing capacitor can be suppressed compared to the first smoothing capacitor. As a result, even when the first control circuit is constantly driven by the second rectifying and smoothing circuit, power consumption of the washing machine can be suppressed.

[0041] The washing machine involved in the fifth embodiment of the present invention is preferably, in the fourth embodiment, further provided with an operating unit, the operating unit having a second control circuit connected to the first control circuit, and the power supply control unit supplies driving power from the AC power supply via the second rectification and smoothing circuit to the first control circuit and the second control circuit in a standby state in which the first switching circuit cuts off the first connection path and the second switching circuit cuts off the second connection path.

[0042] According to the fifth aspect, the first control circuit and the second control circuit can be constantly driven by the second rectifying and smoothing circuit while suppressing power consumption of the washing machine in the standby state where the first rectifying and smoothing circuit and the load are stopped.

[0043] The washing machine involved in the sixth embodiment of the present invention is preferably that, in the fifth embodiment, the operating part further has an operation button, and the second control circuit inputs a control signal for causing the second switching circuit to turn on the second connection path to the first control circuit by obtaining operation information indicating that the operation button has been operated from the operation button.

[0044] According to the sixth aspect, the second control circuit can start driving the first rectifying and smoothing circuit and the load through electronic control triggered by operation information acquired from the operation button.

[0045] The washing machine involved in the seventh embodiment of the present invention is preferably that, in the fifth or sixth embodiment, the operating part also has a communication circuit for receiving a remote operation signal, the communication circuit waits to receive the remote operation signal in the standby state, and the second control circuit inputs a control signal for causing the second switching circuit to turn on the second connection path to the first control circuit by obtaining remote operation information indicating that the communication circuit has received the remote operation signal from the communication circuit.

[0046] According to the seventh aspect, the first rectifying and smoothing circuit and the load can be started by electronic control triggered by remote operation information received from the communication circuit. Furthermore, while the communication circuit is in a standby state awaiting remote operation signals, the first rectifying and smoothing circuit and the load are stopped, thereby reducing power consumption in the washing machine.

[0047] The eighth embodiment of the present disclosure is a control method for a washing machine, comprising: a load that performs actions related to washing; and a power supply control unit that controls the supply of driving power from an AC power supply to the load, the power supply control unit having: a first rectifying and smoothing circuit that is connected between the AC power supply and the load and includes a first smoothing capacitor; a first switching circuit that switches on or off a first connection path that connects the AC power supply to the first rectifying and smoothing circuit; a phase detection circuit that detects the phase of the AC voltage output by the AC power supply; and a first control circuit. In the control method for the washing machine, the first control circuit acquires the phase detected by the phase detection circuit, and based on the acquired phase, the first control circuit causes the first switching circuit to conduct the first connection path at a zero-crossing timing of the AC voltage.

[0048] According to the eighth aspect, a phase detection circuit detects the phase of the AC voltage output by the AC power supply, and a first control circuit causes the first switching circuit to conduct the first connection path at the timing of a zero-crossing of the AC voltage based on the phase detected by the phase detection circuit. This can suppress the inrush current that flows at the moment when drive power begins to be supplied from the AC power supply to the load.

[0049] The present disclosure can also implement the characteristic structures included in this method or apparatus as a program for causing a computer to execute, or as a system for operating according to the program. Furthermore, it goes without saying that such a computer program can be distributed via a computer-readable non-transitory recording medium such as a CD-ROM or a communication network such as the Internet.

[0050] (Embodiments of the present disclosure)

[0051] Below, the embodiments of the present disclosure are described in detail using the accompanying drawings. Elements marked with the same figure mark in different drawings represent the same or corresponding elements. In addition, the constituent elements, the configuration positions of the constituent elements, the connection method, and the order of actions shown in the following embodiments are examples and are not intended to limit the present disclosure. The present disclosure is limited only by the claims. Therefore, the constituent elements that represent the highest concept of the present disclosure among the constituent elements of the following embodiments and are not recorded in the independent claims are not necessarily necessary to achieve the subject of the present disclosure, but are described as constituent elements that constitute a more preferred embodiment.

[0052] Figure 1 1 is a perspective view showing the appearance structure of the washing machine 1 according to the embodiment of the present disclosure. Figure 1 In the example shown, the washing machine 1 is a drum-type washing machine having a drum, but it can also be a vertical washing machine having a washing tub. A display unit 63 using a liquid crystal display or an organic EL (Electro Luminescence) display, etc., and various operation buttons pressed by the user are arranged on the upper front surface of the washing machine 1. The operation buttons include a start button 64, an end button 65, and a remote button 66. The start button 64 is pressed when starting washing. The end button 65 is pressed when forcibly ending the operation of the washing machine 1, etc. The remote button 66 is pressed when setting the washing machine 1 to the remote operation mode. In the remote operation mode, the user can start washing using the washing machine 1 by remote operation using a smartphone, etc.

[0053] Figure 2This diagram illustrates a simplified circuit configuration of washing machine 1. Washing machine 1 includes a load 12 that performs washing-related operations; a power supply control unit 13 that controls the supply of drive power P1 from an AC power source 11 (e.g., a commercial power source) to load 12; and an operating unit 14 that includes the various operating buttons described above. For example, in a drum-type washing machine, load 12 includes a drive motor for rotating the drum; in a vertical-type washing machine, load 12 includes a drive motor for rotating the washing tub. If washing machine 1 is a washer-dryer with a drying function, load 12 includes a heater, a blower fan, and other components.

[0054] The power supply control unit 13 includes a first rectifying and smoothing circuit 21, a second rectifying and smoothing circuit 22, a first control circuit 23, a phase detection circuit 24, a voltage detection circuit 25, a current-limiting resistor 26, a first connection path 31, a second connection path 32, a first relay circuit 41, a second relay circuit 42, a first relay drive circuit 51, and a second relay drive circuit 52. The current-limiting resistor 26 may also be a resistor element or an NTC (Negative Temperature Coefficient) thermistor.

[0055] The first rectifying and smoothing circuit 21 is connected between the AC power supply 11 and the load 12 . The first rectifying and smoothing circuit 21 rectifies and smoothes the AC voltage V0 output from the AC power supply 11 , and supplies DC driving power P1 to the load 12 .

[0056] The second rectifying and smoothing circuit 22 is connected between the AC power supply 11 and the first control circuit 23. The second rectifying and smoothing circuit 22 rectifies and smoothes the AC voltage V0 output by the AC power supply 11, thereby supplying DC drive power P2 to the first control circuit 23. The first control circuit 23 is configured to include a microcontroller and the like.

[0057] Figures 3A to 3C 2 is a circuit diagram showing the circuit configuration of a rectifying and smoothing circuit. Figure 3A The rectifier and smoothing circuit for full-wave rectification is shown. Figure 3B The figure shows a rectifier and smoothing circuit for voltage doubling rectification. Figure 3C The figure shows a rectifier and smoothing circuit for half-wave rectification. Figures 3A to 3CAs shown, the rectifier and smoothing circuit includes at least one diode D and at least one smoothing capacitor C. For the first rectifier and smoothing circuit 21 that supplies high-voltage drive power P1 to the load 12, a rectifier and smoothing circuit that performs voltage doubling rectification is preferably used. For the second rectifier and smoothing circuit 22 that supplies low-voltage drive power P2 to the first control circuit 23, a rectifier and smoothing circuit that performs full-wave rectification or half-wave rectification is preferably used. Furthermore, the electrostatic capacitance of the smoothing capacitor C included in the first rectifier and smoothing circuit 21 (hereinafter referred to as the "first smoothing capacitor") is larger than the electrostatic capacitance of the smoothing capacitor C included in the second rectifier and smoothing circuit 22 (hereinafter referred to as the "second smoothing capacitor").

[0058] The phase detection circuit 24 detects the phase of the AC voltage V0 output from the AC power source 11. The phase detection circuit 24 inputs a signal S13 indicating the detection result of the phase of the AC voltage V0 to the first control circuit 23.

[0059] The voltage detection circuit 25 detects a charge voltage corresponding to the charge storage amount of the first smoothing capacitor 21. The voltage detection circuit 25 inputs a signal S12 indicating the detection result of the charge voltage of the first smoothing capacitor 21 to the first control circuit 23.

[0060] The first rectifying and smoothing circuit 21 is connected to the AC power supply 11 via the first connection path 31 or the second connection path 32. The second relay circuit 42 and the high-resistance current-limiting resistor 26 are connected to the second connection path 32. The first relay circuit 41 is connected to the first connection path 31. That is, the second connection path 32 connects the AC power supply 11 to the first rectifying and smoothing circuit 21 via the current-limiting resistor 26, while the first connection path 31 bypasses the current-limiting resistor 26 and connects the AC power supply 11 to the first rectifying and smoothing circuit 21. The first relay circuit 41 and the second relay circuit 42 are configured using mechanical relays having a coil portion and a contact portion.

[0061] The first relay drive circuit 51 controls the opening and closing operations of the first relay circuit 41 based on the control signal S14 input from the first control circuit 23. The first relay drive circuit 51 closes the first relay circuit 41, thereby connecting the first connection path 31. The first relay drive circuit 51 opens the first relay circuit 41, thereby disconnecting the first connection path 31. The first relay circuit 41 and the first relay drive circuit 51 constitute a first switching circuit for switching the first connection path 31 between on and off.

[0062] The second relay drive circuit 52 controls the opening and closing of the second relay circuit 42 based on the control signal S11 input from the first control circuit 23. The second relay drive circuit 52 closes the second relay circuit 42, thereby connecting the second connection path 32. The second relay drive circuit 52 opens the second relay circuit 42, thereby disconnecting the second connection path 32. The second relay circuit 42 and the second relay drive circuit 52 constitute a second switching circuit for switching the second connection path 32 between on and off.

[0063] The operating unit 14 includes a second control circuit 61, a communication circuit 62, a display unit 63, a start button 64, an end button 65, and a remote button 66. The second control circuit 61 is connected to the first control circuit 23. The second control circuit 61 is configured to include a microcontroller, etc. The driving power P2 is supplied to the second control circuit 61 from the AC power supply 11 via the second rectifying and smoothing circuit 22 and the first control circuit 23. The communication circuit 62 is configured to include a communication module that supports any wireless communication standard such as Wi-Fi or Bluetooth (registered trademark).

[0064] Washing machine 1 has an operating mode, a standby mode, and a remote operation mode.

[0065] The operating mode is a mode in which drive power P1 is supplied from the AC power source 11 via the first rectifying and smoothing circuit 21 to the load 12, causing the load 12 to perform washing-related operations. In the operating mode, the second control circuit 61 controls the load 12 according to user-selected program or menu settings, thereby sequentially performing washing-related operations such as washing, rinsing, and spinning. In the operating mode, drive power P2 is supplied from the AC power source 11 via the second rectifying and smoothing circuit 22 to the first control circuit 23 and the second control circuit 61.

[0066] The standby mode is a state in which washing machine 1 is in standby mode with low power consumption (standby state). In the standby mode, supply of driving power P1 to load 12 is stopped, while supply of driving power P2 to first control circuit 23 and second control circuit 61 is continued.

[0067] The remote operation mode allows remote operation in the standby state. In the remote operation mode, as in the standby mode, the supply of driving power P1 to the load 12 is stopped, while the supply of driving power P2 to the first control circuit 23 and the second control circuit 61 continues.

[0068] In this manner, driving power P2 continues to be supplied to first control circuit 23 and second control circuit 61 regardless of operating mode, standby mode, or remote operation mode. Because the capacitance of the second smoothing capacitor included in second rectifying and smoothing circuit 22 is very small (tens of μF), power consumption due to leakage current from the second smoothing capacitor is also very low. This allows washing machine 1 to be constantly operated with low power consumption.

[0069] Figure 4 and Figure 5 These are a flowchart and a sequence diagram respectively showing a first operation executed by washing machine 1 when start button 64 is pressed in the standby mode.

[0070] When the start button 64 is pressed by the user at time T1 , the second control circuit 61 acquires a signal S21 , which is operation information indicating that the start button 64 has been pressed, from the start button 64 .

[0071] At time T2, the second control circuit 61 inputs a control signal S10 instructing the first control circuit 23 to switch from the standby mode to the operating mode. The control signal S10 instructing the switch from the standby mode to the operating mode corresponds to a control signal for causing the second switching circuit to connect the second connection path 32 .

[0072] Furthermore, when the communication circuit 62 receives a remote operation signal in the remote operation mode, the second control circuit 61 obtains a signal S24 serving as remote operation information from the communication circuit 62. In this case, the second control circuit 61 may input a control signal S10 instructing the first control circuit 23 to transition from the remote operation mode to the operational mode at time T2.

[0073] In step SP11, at time T3, the first control circuit 23 inputs a control signal S11 to the second relay driver circuit 52, instructing it to close the second relay circuit 42. The second relay driver circuit 52 closes the second relay circuit 42. This causes the second connection path 32 to become conductive, and the first smoothing capacitor included in the first rectifying and smoothing circuit 21 to begin charging with the charging current limited by the current-limiting resistor 26. Furthermore, in standby mode, the phase detection circuit 24 is deactivated, and the first control circuit 23 activates the phase detection circuit 24 at time T3.

[0074] In step SP12 , the first control circuit 23 acquires a signal S12 indicating a detection result of the charging voltage of the first smoothing capacitor from the voltage detection circuit 25 .

[0075] In step SP13 , the first control circuit 23 determines whether the charging voltage indicated by the signal S12 is equal to or higher than a predetermined threshold value Vt1 .

[0076] If the charging voltage indicated by the signal S12 is lower than the threshold Vt1 (step SP13: No), in step SP14 the first control circuit 23 determines whether the time has exceeded a predetermined upper limit since the time elapsed from the time T3 at which the control signal S11 was output.

[0077] If there is no timeout (step SP14: No), the first control circuit 23 repeatedly executes the processing of steps SP13 and SP14.

[0078] If the timeout is reached (step SP14: YES), in step SP15, first control circuit 23 inputs signal S15 indicating malfunction of washing machine 1 to second control circuit 61. Second control circuit 61 displays error message S25 on display unit 63 indicating that washing machine 1 has malfunctioned.

[0079] The charging voltage of the first smoothing capacitor gradually increases after the start of charging, and reaches the threshold value Vt1 at time T4.

[0080] When the charging voltage indicated by the signal S12 is equal to or greater than the threshold value Vt1 (step SP13 : YES), in step SP16 , the first control circuit 23 obtains a signal S13 indicating the detection result of the phase of the AC voltage V0 from the phase detection circuit 24 .

[0081] In step SP17, the first control circuit 23 determines whether the current time point is a zero-crossing timing of the AC voltage V0 based on the signal S13. The zero-crossing timing is the time when the AC waveform of the AC voltage V0 intersects the horizontal time axis, that is, the time when the voltage value of the AC voltage V0 reaches zero. The zero-crossing timing is not limited to the instant when the voltage value of the AC voltage V0 reaches zero; it can also have a certain duration during which the voltage value of the AC voltage V0 is substantially zero.

[0082] When the current time point is not a zero-cross timing (step SP17 : No), the first control circuit 23 repeatedly executes the process of step SP17 at time intervals shorter than ½ of the period of the waveform of the AC voltage V0 .

[0083] If the current time point is a zero-cross timing (step SP17: Yes), in step SP18, the first control circuit 23 outputs a control signal S14 at time T5 to instruct the first relay circuit 41 to close. The control signal S14 output from the first control circuit 23 is input to the first relay driver circuit 51. The first relay driver circuit 51 closes the first relay circuit 41. This opens the first connection path 31, allowing the first smoothing capacitor to be charged with a large charging current that is not limited by the current-limiting resistor 26.

[0084] In step SP19, the first control circuit 23 inputs a control signal S11 to the second relay driver circuit 52, instructing the second relay circuit 42 to be disconnected. The second relay driver circuit 52 disconnects the second relay circuit 42. Alternatively, the first control circuit 23 may simultaneously execute the processing of step SP18 and the processing of step SP19. Alternatively, the first control circuit 23 may execute the processing of step SP18 after the processing of step SP19, within a time range in which the leakage current from the first smoothing capacitor does not become a problem.

[0085] The above process completes the transition from standby mode to operation mode. In step SP20, washing machine 1 enters operation mode. In operation mode, second control circuit 61 controls load 12 according to user-selected program or menu settings, thereby sequentially performing washing-related operations such as washing, rinsing, and spinning.

[0086] Figure 6 and Figure 7 These are a flowchart and a timing chart respectively showing a second operation executed by washing machine 1 when start button 64 is pressed in the standby mode.

[0087] In the second operation, the first control circuit 23 executes the process of step SP17A instead of the process of step SP17 in the first operation.

[0088] In step SP17A, the first control circuit 23 calculates a control timing for outputting the control signal S14 based on the signal S13 indicating the detection result of the phase of the AC voltage V0 and the delay time of the first relay circuit 41 .

[0089] In a mechanical relay having a coil portion and a contact portion, a magnetic field needs to be generated to move the movable contact during relay operation. Therefore, a delay time is generated from the time the first control circuit 23 outputs the control signal S14 until the relay operation is completed (the conduction of the first connection path 31 is completed). There are individual differences in this delay time for each relay circuit used. Therefore, the first control circuit 23 calculates the delay time of the first relay circuit 41 installed in the washing machine 1 based on the results of multiple past operations. Then, the first control circuit 23 calculates the timing (time T6) when the delay time of the first relay circuit 41 is retracted from the zero crossing timing (time T5) after the current time point as the control timing for outputting the control signal S14. In addition, when the delay time of the first relay circuit 41 varies due to environmental conditions such as temperature or humidity, the first control circuit 23 can also calculate the delay time of the first relay circuit 41 based on the previous operation result or the most recent multiple operation results.

[0090] In step SP18, the first control circuit 23 outputs a control signal S14 instructing closing the first relay circuit 41 at time T6 corresponding to the control timing calculated in step SP17A. This completes the conduction of the first connection path 31 at the zero-cross timing following the current time point.

[0091] Figure 8 This is a flowchart illustrating the operations performed by washing machine 1 upon completion of washing in operating mode. As described above, second control circuit 61 controls load 12 according to user-selected program or menu settings, thereby sequentially performing washing-related operations such as washing, rinsing, and spinning. Second control circuit 61 receives information from load 12 indicating the completion of this series of operations, causing washing machine 1 to transition from operating mode to standby mode. Furthermore, washing machine 1 transitions from operating mode to standby mode even if the end button 65 is pressed in operating mode.

[0092] The second control circuit 61 inputs a control signal S10 for instructing transition from the operating mode to the standby mode to the first control circuit 23. The control signal S10 for instructing transition from the operating mode to the standby mode corresponds to a control signal for causing the first switching circuit to disconnect the first connection path 31.

[0093] In step SP31, the first control circuit 23 outputs a control signal S14 instructing the first relay circuit 41 to be disconnected. The control signal S14 output from the first control circuit 23 is input to the first relay driver circuit 51. The first relay driver circuit 51 disconnects the first relay circuit 41. This disconnects the first connection path 31, and the first smoothing capacitor begins discharging.

[0094] In step SP32 , the first control circuit 23 acquires a signal S12 indicating a detection result of the charging voltage of the first smoothing capacitor from the voltage detection circuit 25 .

[0095] In step SP33 , the first control circuit 23 determines whether the charging voltage indicated by the signal S12 is lower than a predetermined threshold value Vt2 .

[0096] When the charging voltage indicated by the signal S12 is equal to or higher than the threshold Vt2 (step SP33: No), in step SP34, the first control circuit 23 determines whether the time has exceeded a predetermined upper limit since the time from outputting the control signal S11.

[0097] If there is no timeout (step SP34: No), the first control circuit 23 repeatedly executes the processing of steps SP33 and SP34.

[0098] If the timeout is reached (step SP34: YES), in step SP35, first control circuit 23 inputs signal S15 indicating malfunction of washing machine 1 to second control circuit 61. Second control circuit 61 displays error message S25 on display unit 63 indicating that washing machine 1 has malfunctioned.

[0099] The charging voltage of the first smoothing capacitor gradually decreases after the discharge starts.

[0100] When the charging voltage indicated by signal S12 is lower than threshold value Vt2 (step SP33 : YES), first control circuit 23 starts the standby mode of washing machine 1 in step SP36 .

[0101] According to this embodiment, phase detection circuit 24 detects the phase of AC voltage V0 output by AC power supply 11. First control circuit 23, based on the phase detected by phase detection circuit 24, causes first switching circuit 23 to connect first connection path 31 at the timing of a zero-crossing of AC voltage V0. This suppresses the inrush current that flows at the moment drive power P1 starts to be supplied from AC power supply 11 to load 12.

[0102] In addition, according to Figure 6 、 Figure 7 In the process shown, the first control circuit 23 controls the timing of outputting the control signal S14 based on the phase detected by the phase detection circuit 24 and the delay time from outputting the control signal S14 until the first connection path 31 completes conduction. This allows the timing of the completion of conduction of the first connection path 31 to be accurately aligned with the zero-crossing timing of the AC voltage V0. As a result, inrush current can be more effectively suppressed.

[0103] Furthermore, according to this embodiment, the first control circuit 23 causes the first switching circuit to connect the first connection path 31 at a zero-cross timing after the charged voltage of the first smoothing capacitor reaches or exceeds the threshold value Vt1. This reduces the uncharged capacitance of the first smoothing capacitor at the moment the first switching circuit connects the first connection path 31. Consequently, inrush current can be more effectively suppressed.

[0104] Furthermore, according to this embodiment, the capacitance of the second smoothing capacitor included in second rectifying and smoothing circuit 22 is smaller than that of the first smoothing capacitor. Therefore, leakage current from the second smoothing capacitor can be suppressed compared to the first smoothing capacitor. Consequently, even when first control circuit 23 is constantly driven by second rectifying and smoothing circuit 22, power consumption in washing machine 1 can be suppressed.

[0105] Furthermore, according to this embodiment, the first control circuit 23 and the second control circuit 61 can be constantly driven by the second rectifying and smoothing circuit 22 while suppressing the power consumption of the washing machine 1 in the standby state where the first rectifying and smoothing circuit 21 and the load 12 are stopped.

[0106] Furthermore, according to the present embodiment, the second control circuit 61 can start driving the first rectifying and smoothing circuit 21 and the load 12 through electronic control triggered by acquisition of operation information from the start button 64 .

[0107] Furthermore, according to this embodiment, the driving of the first rectifying and smoothing circuit 21 and the load 12 can be started by electronic control triggered by the remote operation information received from the communication circuit 62. Furthermore, in a standby state where the communication circuit 62 is waiting to receive a remote operation signal, the driving of the first rectifying and smoothing circuit 21 and the load 12 is stopped, thereby suppressing the power consumption of the washing machine 1.

[0108] (First Modification)

[0109] Figure 9 This is a diagram showing a simplified circuit configuration of a washing machine 1 according to a first modification. Figure 2 The circuit structure shown omits the second rectifying and smoothing circuit 22, the second relay driving circuit 52, the communication circuit 62, the start button 64, the end button 65, and the remote button 66. In addition, a switch 70 such as a physical switch is provided instead of Figure 2 The second relay circuit 42 shown in FIG. In the washing machine 1 according to the first modification, the standby mode and remote operation mode are omitted from the washing machine 1 according to the embodiment. Furthermore, in the washing machine 1 according to the first modification, the always-on driving function is also omitted from the washing machine 1 according to the embodiment.

[0110] Figure 10 1 is a flowchart showing a first operation performed by washing machine 1 when switch 70 is turned on while washing machine 1 is powered off.

[0111] When the user turns on switch 70 while washing machine 1 is powered off, second connection path 32 is connected, and charging of the first smoothing capacitor included in first rectifying and smoothing circuit 21 begins with the charging current limited by current limiting resistor 26. Furthermore, phase detection circuit 24 is activated.

[0112] The charging voltage of the first smoothing capacitor included in the first rectifying and smoothing circuit 21 gradually increases after charging is started. When the charging voltage indicated by the signal S12 increases to a predetermined value or more, the first control circuit 23 is activated.

[0113] In step SP41 , the first control circuit 23 acquires a signal S13 indicating a detection result of the phase of the AC voltage V0 from the phase detection circuit 24 .

[0114] In step SP42 , the first control circuit 23 determines whether the current time point is a zero-cross timing of the AC voltage V0 based on the signal S13 .

[0115] When the current time point is not a zero-cross timing (step SP42 : No), the first control circuit 23 repeatedly executes the process of step SP42 at time intervals shorter than ½ of the period of the waveform of the AC voltage V0 .

[0116] If the current time point is a zero-cross timing (step SP42: Yes), in step SP43, the first control circuit 23 outputs a control signal S14 instructing the first relay circuit 41 to close. The control signal S14 output from the first control circuit 23 is input to the first relay driver circuit 51. The first relay driver circuit 51 closes the first relay circuit 41. This causes the first connection path 31 to become conductive, allowing the first smoothing capacitor to be charged with a large charging current not limited by the current-limiting resistor 26.

[0117] In step SP44, washing machine 1 starts the operation mode.

[0118] Figure 11 1 is a flowchart showing a second operation performed by washing machine 1 when switch 70 is turned on while washing machine 1 is powered off.

[0119] In the second operation, the first control circuit 23 executes the process of step SP42A instead of the process of step SP42 in the first operation.

[0120] In step SP42A, the first control circuit 23 calculates the control timing for outputting the control signal S14 based on the signal S13 indicating the phase detection result of the AC voltage V0 and the delay time of the first relay circuit 41. The first control circuit 23 calculates the delay time of the first relay circuit 41 installed in the washing machine 1 based on the results of multiple past operations. The first control circuit 23 then calculates the timing of the zero-crossing timing subsequent to the current time point, which is the delay time of the first relay circuit 41, as the control timing for outputting the control signal S14. Furthermore, if the delay time of the first relay circuit 41 fluctuates due to environmental conditions such as temperature or humidity, the first control circuit 23 may calculate the delay time of the first relay circuit 41 based on the previous operation result or the results of multiple recent operations.

[0121] In step SP43, the first control circuit 23 outputs a control signal S14 for instructing closing the first relay circuit 41 at the control timing calculated in step SP42A. Thus, the timing of completing the conduction of the first connection path 31 coincides with the zero-cross timing subsequent to the current time point.

[0122] According to this variation, similarly to the above-described embodiment, phase detection circuit 24 detects the phase of AC voltage V0 output by AC power supply 11. First control circuit 23, based on the phase detected by phase detection circuit 24, causes first switching circuit 31 to connect first connection path 31 at the timing of a zero-cross of AC voltage V0. Thus, similarly to the above-described embodiment, it is possible to suppress the inrush current that flows at the moment when drive power P1 starts to be supplied from AC power supply 11 to load 12.

[0123] (Second Modification)

[0124] In the above embodiment, the driving of the phase detection circuit 24 is stopped in the standby mode and the remote operation mode. However, by using a low-power phase detection circuit 24 , the phase detection circuit 24 can be driven at all times including in the standby mode and the remote operation mode.

[0125] In this case, when the first control circuit 23 receives the control signal S10 from the second control circuit 61, which instructs the transition from the standby mode or the remote operation mode to the operation mode, it obtains the signal S13 indicating the phase detection result of the AC voltage V0 from the phase detection circuit 24. In step SP11, the first control circuit 23 may also input the control signal S11 to the second relay drive circuit 52 at the zero-cross timing, instructing the second relay circuit 42 to close.

[0126] According to this variation, first control circuit 23 causes second switching circuit 23 to connect second connection path 32 at the zero-crossing timing of AC voltage V0 based on the phase detected by phase detection circuit 24. This suppresses the current flowing at the moment drive power P1 starts to be supplied from AC power source 11 to load 12, and reduces energy loss by lowering the resistance value of current-limiting resistor 26.

[0127] Industrial applicability

[0128] The present disclosure can be widely applied to vertical washing machines, drum washing machines, and the like.

[0129] Description of Reference Numerals

[0130] 1: Washing machine; 11: AC power supply; 12: Load; 13: Power supply control unit; 14: Operating unit; 21: First rectifier and smoothing circuit; 22: Second rectifier and smoothing circuit; 23: First control circuit; 24: Phase detection circuit; 25: Voltage detection circuit; 26: Current-limiting resistor; 31: First connection path; 32: Second connection path; 41: First relay circuit; 42: Second relay circuit; 51: First relay drive circuit; 52: Second relay drive circuit; 61: Second control circuit; 62: Communication circuit; 63: Display unit; 64: Start button; 65: End button; 66: Remote button; 70: Switch.

Claims

1. A washing machine comprising: a load, which performs actions associated with washing; and a power supply control unit that controls the supply of driving power from the AC power supply to the load, in, The power supply control unit includes: a first rectifying and smoothing circuit connected between the AC power source and the load, comprising a first smoothing capacitor; a first switching circuit configured to switch on or off a first connection path connecting the AC power source to the first rectifying and smoothing circuit; a phase detection circuit for detecting the phase of the AC voltage output by the AC power supply; as well as a first control circuit, The first control circuit causes the first switching circuit to conduct the first connection path at a zero-cross timing of the AC voltage based on the phase detected by the phase detection circuit.

2. The washing machine according to claim 1, wherein The first control circuit inputs a control signal to the first switching circuit for causing the first switching circuit to conduct the first connection path. The first control circuit controls a timing of outputting the control signal based on the phase detected by the phase detection circuit and a delay time from when the control signal is output until conduction of the first connection path is completed.

3. The washing machine according to claim 1 or 2, further comprising: a second switching circuit configured to switch on or off a second connection path connecting the AC power source and the first rectifying and smoothing circuit via a current-limiting resistor; and a voltage detection circuit that detects a charging voltage of the first smoothing capacitor, The first connection path connects the AC power supply to the first rectifying and smoothing circuit in a manner that bypasses the current limiting resistor. The first control circuit starts charging the first smoothing capacitor from the AC power supply by causing the second switching circuit to connect the second connection path. The first control circuit causes the first switching circuit to conduct the first connection path at the zero-cross timing after the charging voltage becomes equal to or greater than a threshold value, based on the charging voltage detected by the voltage detection circuit and the phase detected by the phase detection circuit.

4. The washing machine according to claim 3, wherein: The device further includes a second rectifying and smoothing circuit connected between the AC power supply and the first control circuit, and including a second smoothing capacitor having a smaller electrostatic capacitance than the first smoothing capacitor.

5. The washing machine according to claim 4, wherein further comprising an operating unit having a second control circuit connected to the first control circuit, The power supply control unit supplies driving power from the AC power supply via the second rectifying and smoothing circuit to the first control circuit and the second control circuit in a standby state in which the first switching circuit disconnects the first connection path and the second switching circuit disconnects the second connection path.

6. The washing machine according to claim 5, wherein The operating part also has an operating button. The second control circuit acquires operation information indicating that the operation button has been operated from the operation button, and thereby inputs a control signal for causing the second switching circuit to connect the second connection path to the first control circuit.

7. The washing machine according to claim 5, wherein The operation unit also has a communication circuit for receiving remote operation signals. The communication circuit waits for receiving the remote operation signal in the standby state, The second control circuit receives remote operation information indicating that the communication circuit has received the remote operation signal from the communication circuit, thereby inputting a control signal for causing the second switching circuit to connect the second connection path to the first control circuit.

8. A method for controlling a washing machine, wherein: The washing machine includes: a load that performs an action related to washing; and a power supply control unit that controls the supply of driving power from an AC power supply to the load, the power supply control unit comprising: a first rectifying and smoothing circuit connected between the AC power supply and the load and including a first smoothing capacitor; a first switching circuit that switches on and off a first connection path that connects the AC power supply to the first rectifying and smoothing circuit; and a phase detection circuit that detects the phase of the AC voltage output by the AC power supply; as well as The first control circuit, in the control method of the washing machine, The first control circuit acquires the phase detected by the phase detection circuit, The first control circuit causes the first switching circuit to conduct the first connection path at a zero-crossing timing of the AC voltage based on the acquired phase.

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