Washing machine and control method of the same

Abstract

To acquire a washing machine which can suppress a rush current which flows at the moment when supply of a drive power source starts from an AC power source to a load.SOLUTION: A washing machine includes: a load for performing an operation regarding washing; and a power source control part for controlling the supply of drive power source from an AC power source to the load. The power source control part includes: a first rectifying and smoothing circuit containing a first smoothing capacitor connected between the AC power source and the load; a first switching circuit for switching conduction or cut-off of a first connection path for connecting the AC power source and the first rectifying and smoothing circuit; a phase detection circuit for detecting the phase of an AC voltage which the AC power source outputs; and a first control circuit. The first control circuit conducts the first connection path to the first switching circuit at zero-cross timing of the AC voltage, based on the phase detected by the phase detection circuit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] A washing machine according to the background art is disclosed in, for example, Patent Document 1. The washing machine includes a main microcomputer, an operating load, a sub-microcomputer, a communication unit, a power supply, and a power control unit. In a communication mode in which the communication unit communicates, the sub-microcomputer, the communication unit, and the power control unit are constantly supplied with power supply voltage from the power supply. In the communication mode and in a power saving mode in which the operating load is not controlled, the power control unit stops the supply of power supply voltage from the power supply to the main microcomputer and the operating load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-159989 Summary of the Invention [Problem to be solved by the invention]

[0004] In the washing machine disclosed in the above Patent Document 1, no measures are taken against the inrush current that flows the moment the power supply device starts to supply power supply voltage to the operating load.

[0005] 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 the instant the supply of drive power from an AC power source to a load begins. [Means for solving the problem]

[0006] A washing machine according to one aspect of the present disclosure includes a load that performs a washing-related operation, and a power supply control unit that controls the supply of drive power from an AC power supply to the load. The power supply control unit includes: a first rectifying and smoothing circuit including a first smoothing capacitor connected between the AC power supply and the load; a first switching circuit that switches between conduction and interruption 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 an 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-cross timing of the AC voltage based on the phase detected by the phase detection circuit.

[0007] A method for controlling a washing machine according to another aspect of the present disclosure includes a load that performs a washing-related operation and a power supply control unit that controls the supply of drive power from an AC power supply to the load, wherein the power supply control unit has: a first rectifying and smoothing circuit including a first smoothing capacitor connected between the AC power supply and the load; a first switching circuit that switches between conduction and interruption 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 an AC voltage output by the AC power supply; and a first control circuit, wherein the first control circuit acquires the phase detected by the phase detection circuit and, based on the acquired phase, causes the first switching circuit to make the first connection path conductive at a zero-cross timing of the AC voltage. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to suppress the inrush current that flows the moment the supply of drive power from the AC power supply to the load begins. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an external configuration of a washing machine according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a simplified diagram showing the circuit configuration of the washing machine 1. [Figure 3A] FIG. 2 is a circuit diagram showing the circuit configuration of a rectifying and smoothing circuit. [Figure 3B] FIG. 2 is a circuit diagram showing the circuit configuration of a rectifying and smoothing circuit. [Figure 3C] FIG. 2 is a circuit diagram showing the circuit configuration of a rectifying and smoothing circuit. [Figure 4] 10 is a flowchart showing a first operation that the washing machine executes when the start button is pressed in standby mode. [Figure 5] 10 is a timing chart showing a first operation performed by the washing machine when the start button is pressed in standby mode. [Figure 6] 10 is a flowchart showing a second operation performed by the washing machine when the start button is pressed in the standby mode. [Figure 7] 10 is a timing chart showing a second operation performed by the washing machine when the start button is pressed in the standby mode. [Figure 8] 10 is a flowchart showing the operations performed by the washing machine when washing is completed in the operation mode. [Figure 9] FIG. 10 is a simplified diagram showing the circuit configuration of a washing machine according to a first modified example. [Figure 10] 10 is a flowchart showing a first operation that the washing machine executes when the switch is turned on while the washing machine is powered off. [Figure 11] 10 is a flowchart showing a second operation performed by the washing machine when the switch is turned on while the washing machine is powered off. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Findings that formed the basis of this disclosure) A washing machine according to the background art includes a load such as a drive motor that rotates a washing tub or drum, a rectifying and smoothing circuit connected between an AC commercial power source and the load, a relay circuit that switches the connection path between the commercial power source and the rectifying and smoothing circuit on or off, and a control circuit such as a microcomputer. The rectifying and smoothing circuit has at least one diode and a smoothing capacitor with a large capacitance.

[0011] When a user presses the power switch of a washing machine, the smoothing capacitor begins to be charged by the commercial power supply through a current flowing through a path via a current-limiting resistor. After a certain time has passed, when the charging voltage of the smoothing capacitor rises above a threshold, the control circuit is activated. The control circuit controls a relay circuit to open the connection path between the commercial power supply and the rectifying and smoothing circuit. To avoid energy loss when driving the load, no current-limiting resistor is connected to the connection path.

[0012] The moment the relay circuit closes the connection path, a large inrush current flows to charge the uncharged capacitance of the smoothing capacitor. This inrush current can be particularly large if the connection path closes near the peak of the AC voltage waveform output by the commercial power supply. This can result in excessive heat generation or circuit element failure, potentially causing the washing machine to malfunction.

[0013] In order to solve this problem, the present inventor discovered that inrush current can be suppressed by matching the timing at which the relay circuit opens the connection path with the zero-cross timing of the waveform of the AC voltage output by the commercial power supply, and came up with the present disclosure.

[0014] Next, each aspect of the present disclosure will be described.

[0015] A washing machine according to a first aspect of the present disclosure includes a load that performs a washing-related operation, and a power supply control unit that controls the supply of drive power from an AC power supply to the load, wherein the power supply control unit includes: a first rectifying and smoothing circuit including a first smoothing capacitor connected between the AC power supply and the load; a first switching circuit that switches between conduction and interruption 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 an AC voltage output by the AC power supply; and a first control circuit, wherein the first control circuit causes the first switching circuit to conduct the first connection path at zero-cross timings of the AC voltage based on the phase detected by the phase detection circuit.

[0016] According to the first aspect, the phase detection circuit detects the phase of the AC voltage output by the AC power supply, and 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, thereby suppressing an inrush current that flows at the moment when the AC power supply starts supplying drive power to the load.

[0017] In a washing machine according to a second aspect of the present disclosure, in the first aspect, the first control circuit inputs a control signal to the first switching circuit to make the first connection path conductive, and controls the timing of outputting the control signal based on the phase detected by the phase detection circuit and the delay time from when the control signal is output until the first connection path is made conductive.

[0018] 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 when the control signal is output until the first connection path is fully conductive. This allows the timing at which the first connection path is fully conductive to coincide with the zero-cross timing of the AC voltage with high precision. As a result, inrush current can be more effectively suppressed.

[0019] A washing machine according to a third aspect of the present disclosure, in the first or second aspect, further includes a second switching circuit that switches between conduction and interruption of a second connection path that connects 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, wherein the first connection path connects the AC power supply and the first rectifying and smoothing circuit, bypassing the current limiting resistor, and the first control circuit causes the second switching circuit to conduct the second connection path, thereby starting charging of the first smoothing capacitor by the AC power supply, and based on the charging voltage detected by the voltage detection circuit and the phase detected by the phase detection 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.

[0020] According to the third aspect, the first control circuit causes the first switching circuit to conduct the first connection path at a zero-crossing timing after the charging voltage of the first smoothing capacitor becomes equal to or greater than the threshold value. This reduces the uncharged capacitance of the first smoothing capacitor at the moment when the first switching circuit causes the first connection path to be conductive. As a result, inrush current can be more effectively suppressed.

[0021] The washing machine according to a fourth aspect of the present disclosure may be the third aspect, further comprising a second rectifying and smoothing circuit including a second smoothing capacitor connected between the AC power supply and the first control circuit and having a smaller capacitance than the first smoothing capacitor.

[0022] According to the fourth aspect, the second smoothing capacitor included in the second rectifying and smoothing circuit has a smaller capacitance than the first smoothing capacitor, and therefore the leakage current from the second smoothing capacitor can be suppressed more than the first smoothing capacitor. As a result, even if the first control circuit is constantly driven by the second rectifying and smoothing circuit, it is possible to suppress the power consumption of the washing machine.

[0023] A washing machine according to a fifth aspect of the present disclosure is the fourth aspect, further comprising an operation unit having a second control circuit connected to the first control circuit, and the power supply control unit supplies drive power from the AC power supply to the first control circuit and the second control circuit via the second rectifying and smoothing 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.

[0024] According to the fifth aspect, in a standby state in which the first rectifying and smoothing circuit and the load are not driven, the first control circuit and the second control circuit can be driven constantly by the second rectifying and smoothing circuit while suppressing the power consumption of the washing machine.

[0025] A washing machine according to a sixth aspect of the present disclosure is the fifth aspect, wherein the operation unit further has an operation button, and the second control circuit obtains operation information from the operation button indicating that the operation button has been operated, and inputs a control signal to the first control circuit to cause the second switching circuit to make the second connection path conductive.

[0026] According to the sixth aspect, the second control circuit can start driving the first rectifying smoothing circuit and the load by electronic control triggered by the acquisition of operation information from the operation button.

[0027] A washing machine according to a seventh aspect of the present disclosure is preferably the fifth or sixth aspect, wherein the operation unit further has a communication circuit that receives a remote control signal, the communication circuit waits to receive the remote control signal in the standby state, and the second control circuit obtains remote control information from the communication circuit indicating that the communication circuit has received the remote control signal, and inputs a control signal to the first control circuit to cause the second switching circuit to open the second connection path.

[0028] According to the seventh aspect, the drive of the first rectifying smoothing circuit and the load can be started by electronic control triggered by the acquisition of remote control information from the communication circuit. Also, in a standby state in which the communication circuit is waiting to receive a remote control signal, the drive of the first rectifying smoothing circuit and the load is stopped, thereby reducing the power consumption of the washing machine.

[0029] A method for controlling a washing machine according to an eighth aspect of the present disclosure includes a load that performs a washing-related operation and a power supply control unit that controls the supply of drive power from an AC power supply to the load, wherein the power supply control unit has: a first rectifying and smoothing circuit including a first smoothing capacitor connected between the AC power supply and the load; a first switching circuit that switches between conduction and interruption 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 an AC voltage output by the AC power supply; and a first control circuit, wherein the first control circuit acquires the phase detected by the phase detection circuit and, based on the acquired phase, causes the first switching circuit to make the first connection path conductive at a zero-cross timing of the AC voltage.

[0030] According to an eighth aspect, the phase detection circuit detects the phase of the AC voltage output by the AC power supply, and the first control circuit causes the first switching circuit to make the first connection path conductive at a zero-cross timing of the AC voltage based on the phase detected by the phase detection circuit, thereby suppressing an inrush current that flows at the moment when the AC power supply starts supplying drive power to the load.

[0031] The present disclosure can also be realized as a program that causes a computer to execute each characteristic configuration included in such a method or apparatus, or as a system operated by this program. Needless to say, such a computer program can be distributed on a computer-readable non-transitory recording medium such as a CD-ROM or via a communication network such as the Internet.

[0032] (Embodiments of the present disclosure) Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Elements with the same reference numerals in different drawings indicate the same or corresponding elements. Furthermore, the components, the layout positions of the components, the connection forms, the order of operations, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. The present disclosure is limited only by the claims. Therefore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept of the present disclosure are not necessarily required to achieve the objectives of the present disclosure, but are described as constituting more preferred forms.

[0033] FIG. 1 is a diagram showing the external configuration of a washing machine 1 according to an embodiment of the present disclosure. In the example shown in FIG. 1, the washing machine 1 is a drum-type washing machine having a drum, but it may also be a vertical washing machine having a washing tub. A display unit 63 using a liquid crystal display, an organic electroluminescence display, or the like, and various operation buttons to be 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 to start washing. The end button 65 is pressed to forcefully terminate the operation of the washing machine 1, for example. The remote button 66 is pressed to set the washing machine 1 to a remote control mode. In the remote control mode, a user can start washing using the washing machine 1 by remote control using a smartphone, for example.

[0034] 2 is a simplified diagram showing the circuit configuration of washing machine 1. Washing machine 1 includes load 12 that performs washing-related operations, power supply control unit 13 that controls the supply of drive power P1 from AC power supply 11 such as a commercial power supply to load 12, and operation unit 14 that includes the various operation buttons and the like. Load 12 includes, for example, a drive motor for rotating the drum in a drum-type washing machine, and a drive motor for rotating the washing tub in a vertical washing machine. If washing machine 1 is a washer-dryer with a drying function, load 12 includes a heater, a blower fan, and the like.

[0035] The power supply control unit 13 has 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 be a resistive element or an NTC (Negative Temperature Coefficient) thermistor, etc.

[0036] 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 by the AC power supply 11, thereby supplying a DC driving power supply P1 to the load 12.

[0037] 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 from the AC power supply 11, thereby supplying a DC drive power supply P2 to the first control circuit 23. The first control circuit 23 is configured to include a microcontroller and the like.

[0038] 3A to 3C are circuit diagrams showing the circuit configuration of a rectifying / smoothing circuit. FIG. 3A shows a rectifying / smoothing circuit that performs full-wave rectification, FIG. 3B shows a rectifying / smoothing circuit that performs voltage-doubler rectification, and FIG. 3C shows a rectifying / smoothing circuit that performs half-wave rectification. As shown in FIGS. 3A to 3C, the rectifying / smoothing circuit includes at least one diode D and at least one smoothing capacitor C. A rectifying / smoothing circuit that performs voltage-doubler rectification is preferably used for the first rectifying / smoothing circuit 21 that supplies a high-voltage drive power source P1 to the load 12. A rectifying / smoothing circuit that performs full-wave rectification or half-wave rectification is preferably used for the second rectifying / smoothing circuit 22 that supplies a low-voltage drive power source P2 to the first control circuit 23. Furthermore, the capacitance of the smoothing capacitor C included in the first rectifying / smoothing circuit 21 (hereinafter referred to as the "first smoothing capacitor") is greater than the capacitance of the smoothing capacitor C included in the second rectifying / smoothing circuit 22 (hereinafter referred to as the "second smoothing capacitor").

[0039] The phase detection circuit detects the phase of the AC voltage V0 output by the AC power supply 11. The phase detection circuit inputs a signal S13 indicating the detection result of the phase of the AC voltage V0 to the first control circuit .

[0040] The voltage detection circuit 25 detects a charging voltage corresponding to the amount of charge stored in the first smoothing capacitor. The voltage detection circuit 25 inputs a signal S12 indicating the detection result of the charging voltage of the first smoothing capacitor to the first control circuit 23.

[0041] The first rectifying and smoothing circuit 21 is connected to the AC power supply 11 via a first connection path 31 or a second connection path 32. A second relay circuit 42 and a current-limiting resistor 26 having a high resistance value are connected to the second connection path 32. A first relay circuit 41 is connected to the first connection path 31. In other words, the second connection path 32 connects the AC power supply 11 and the first rectifying and smoothing circuit 21 via the current-limiting resistor 26, and the first connection path 31 connects the AC power supply 11 and the first rectifying and smoothing circuit 21, bypassing the current-limiting resistor 26. The first relay circuit 41 and the second relay circuit 42 are configured using a mechanical relay or the like having a coil portion and a contact portion.

[0042] The first relay drive circuit 51 controls the opening and closing operation of the first relay circuit 41 based on a control signal S14 input from the first control circuit 23. When the first relay drive circuit 51 closes the first relay circuit 41, the first connection path 31 is made conductive. When the first relay drive circuit 51 opens the first relay circuit 41, the first connection path 31 is cut off. The first relay circuit 41 and the first relay drive circuit 51 constitute a first switching circuit that switches the first connection path 31 between conductive and cut off.

[0043] The second relay drive circuit 52 controls the opening and closing operation of the second relay circuit 42 based on a control signal S11 input from the first control circuit 23. When the second relay drive circuit 52 closes the second relay circuit 42, the second connection path 32 is made conductive. When the second relay drive circuit 52 opens the second relay circuit 42, the second connection path 32 is cut off. The second relay circuit 42 and the second relay drive circuit 52 constitute a second switching circuit that switches the second connection path 32 between conductive and cut off.

[0044] The operation unit 14 has 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 and the like. A driving power source P2 is supplied to the second control circuit 61 from the AC power source 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 compatible with any wireless communication standard such as Wi-Fi or Bluetooth (registered trademark).

[0045] The washing machine 1 has an operating mode, a standby mode, and a remote control mode.

[0046] The operating mode is a mode in which the load 12 performs washing-related operations by supplying a driving power source P1 from the AC power source 11 to the load 12 via the first rectifying and smoothing circuit 21. In the operating mode, the second control circuit 61 controls the load 12 in accordance with setting information such as a course or menu selected by the user, thereby sequentially performing washing-related operations such as washing, rinsing, and spin-drying. In the operating mode, the first control circuit 23 and the second control circuit 61 are supplied with a driving power source P2 from the AC power source 11 via the second rectifying and smoothing circuit 22.

[0047] The standby mode is a state (standby state) in which the washing machine 1 is on standby with low power consumption. In the standby mode, the supply of the drive power source P1 to the load 12 is stopped, and the supply of the drive power source P2 to the first control circuit 23 and the second control circuit 61 is continued.

[0048] The remote control mode is a mode in which remote control is permitted in the standby state. In the remote control mode, as in the standby mode, the supply of the drive power source P1 to the load 12 is stopped, while the supply of the drive power source P2 to the first control circuit 23 and the second control circuit 61 is continued.

[0049] In this way, in any of the operation mode, standby mode, and remote control mode, the supply of drive power source P2 to first control circuit 23 and second control circuit 61 continues. Since the capacitance of the second smoothing capacitor included in second rectifying smoothing circuit 22 is sufficiently small (several tens of μF), the power consumption caused by leakage current from the second smoothing capacitor is also sufficiently small. This allows washing machine 1 to be constantly driven with low power consumption.

[0050] 4 and 5 are a flowchart and a timing chart, respectively, showing a first operation that the washing machine 1 executes when the start button 64 is pressed in the standby mode.

[0051] When the user presses the start button 64 at time T1, the second control circuit 61 acquires from the start button 64 a signal S21 which is operation information indicating that the start button 64 has been pressed.

[0052] At time T2, the second control circuit 61 inputs a control signal S10 instructing a transition from the standby mode to the operation mode to the first control circuit 23. The control signal S10 instructing a transition from the standby mode to the operation mode corresponds to a control signal that causes the second switching circuit to make the second connection path 32 conductive.

[0053] When the communication circuit 62 receives a remote control signal in the remote control mode, the second control circuit 61 acquires a signal S24, which is remote control information, from the communication circuit 62. In this case, the second control circuit 61 may input a control signal S10, which instructs the first control circuit 23 to transition from the remote control mode to the operation mode, at time T2.

[0054] In step SP11, the first control circuit 23 inputs a control signal S11 to the second relay drive circuit 52 at time T3, instructing the second relay circuit 42 to be closed. The second relay drive circuit 52 closes the second relay circuit 42. This causes the second connection path 32 to be conductive, and charging of the first smoothing capacitor included in the first rectifying and smoothing circuit 21 begins with the charging current limited by the current limiting resistor 26. Furthermore, in the standby mode, the phase detection circuit 24 is stopped from operating, and the first control circuit 23 activates the phase detection circuit 24 at time T3.

[0055] In step SP12, the first control circuit 23 acquires from the voltage detection circuit 25 a signal S12 indicating the detection result of the charging voltage of the first smoothing capacitor.

[0056] In step SP13, the first control circuit 23 determines whether the charging voltage indicated by the signal S12 is equal to or greater than a predetermined threshold value Vt1.

[0057] If the charging voltage indicated by the signal S12 is less than the threshold value Vt1 (step SP13: NO), in step SP14 the first control circuit 23 determines whether a timeout has occurred because the elapsed time from the time T3 at which the control signal S11 was output exceeds a predetermined upper limit value.

[0058] If the timeout has not occurred (step SP14: NO), the first control circuit 23 repeatedly executes the processes of steps SP13 and SP14.

[0059] If a timeout occurs (step SP14: YES), in step SP15, first control circuit 23 inputs signal S15 indicating a malfunction of washing machine 1 to second control circuit 61. Second control circuit 61 displays an error message S25 indicating that washing machine 1 has broken down on display unit 63, thereby displaying an error message.

[0060] The charging voltage of the first smoothing capacitor gradually increases after the start of charging, and reaches the threshold value Vt1 at time T4.

[0061] If the charging voltage indicated by the signal S12 is equal to or higher than the threshold value Vt1 (step SP13: YES), the first control circuit 23 acquires from the phase detection circuit 24 a signal S13 indicating the detection result of the phase of the AC voltage V0 in step SP16.

[0062] In step SP17, the first control circuit 23 determines whether the current time is a zero-cross timing of the AC voltage V0 based on the signal S13. The zero-cross timing is the timing at which the AC waveform of the AC voltage V0 crosses the horizontal time axis, that is, the timing at which the voltage value of the AC voltage V0 becomes zero. The zero-cross timing may not only be the instant at which the voltage value of the AC voltage V0 becomes zero, but may also be a certain time duration at which the voltage value of the AC voltage V0 becomes approximately zero.

[0063] If the current time is not the zero-cross timing (step SP17: NO), the first control circuit 23 repeatedly executes the process of step SP17 at time intervals shorter than 1 / 2 the period of the waveform of the AC voltage V0.

[0064] If the current time is the zero-cross timing (step SP17: YES), in step SP18, the first control circuit 23 outputs a control signal S14 that instructs to close the first relay circuit 41 at time T5. The control signal S14 output from the first control circuit 23 is input to the first relay drive circuit 51. The first relay drive circuit 51 closes the first relay circuit 41. As a result, the first connection path 31 becomes conductive, and the first smoothing capacitor is charged by a large charging current that is not limited by the current limiting resistor 26.

[0065] In step SP19, the first control circuit 23 inputs a control signal S11, which instructs the second relay drive circuit 52 to open the second relay circuit 42. The second relay drive circuit 52 opens the second relay circuit 42. The first control circuit 23 may execute the process of step SP18 and the process of step SP19 simultaneously. Alternatively, the first control circuit 23 may execute the process of step SP18 after the process of step SP19, within a time difference range in which leakage current from the first smoothing capacitor does not pose a problem.

[0066] The above process completes the transition from standby mode to operating mode, and the washing machine 1 starts operating mode in step SP20. In operating mode, the second control circuit 61 controls the load 12 in accordance with setting information such as a course or menu selected by the user, thereby sequentially performing washing operations such as washing, rinsing, and spin-drying.

[0067] 6 and 7 are a flowchart and a timing chart, respectively, showing a second operation that the washing machine 1 executes when the start button 64 is pressed in the standby mode.

[0068] 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.

[0069] In step SP17A, the first control circuit 23 calculates the 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 in the first relay circuit 41.

[0070] A mechanical relay having a coil and a contact section must generate a magnetic field to move the movable contact during relay operation. Therefore, a delay time occurs between when the first control circuit 23 outputs the control signal S14 and when the relay operation is completed (when the first connection path 31 is fully conductive). This delay time varies depending on the relay circuit used. Therefore, the first control circuit 23 calculates the delay time of the first relay circuit 41 implemented in the washing machine 1 based on the results of multiple past operations. The first control circuit 23 then calculates the control timing for outputting the control signal S14 as the timing (time T6) that is the delay time of the first relay circuit 41 prior to the next zero-crossing timing (time T5) from the current time. If the delay time of the first relay circuit 41 varies 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 results of the previous operation or the results of the most recent operations.

[0071] In step SP18, the first control circuit 23 outputs the control signal S14 instructing to close the first relay circuit 41 at time T6, which corresponds to the control timing calculated in step SP17A. As a result, the timing at which the conduction of the first connection path 31 is completed coincides with the next zero-cross timing at the current time.

[0072] 8 is a flowchart showing the operations performed by the washing machine 1 when washing is completed in the operating mode. As described above, the second control circuit 61 controls the load 12 in accordance with setting information such as a course or menu selected by the user, thereby sequentially performing washing-related operations such as washing, rinsing, and spin-drying. When the second control circuit 61 acquires information from the load 12 indicating that this series of operations has been completed, the washing machine 1 transitions from the operating mode to the standby mode. Note that the washing machine 1 also transitions from the operating mode to the standby mode when the end button 65 is pressed in the operating mode.

[0073] The second control circuit 61 inputs a control signal S10 instructing a transition from the operation mode to the standby mode to the first control circuit 23. The control signal S10 instructing a transition from the operation mode to the standby mode corresponds to a control signal that causes the first switching circuit to cut off the first connection path 31.

[0074] In step SP31, the first control circuit 23 outputs a control signal S14 instructing to open the first relay circuit 41. The control signal S14 output from the first control circuit 23 is input to the first relay drive circuit 51. The first relay drive circuit 51 opens the first relay circuit 41. This breaks the first connection path 31, and discharging of the first smoothing capacitor begins.

[0075] In step SP32, the first control circuit 23 acquires from the voltage detection circuit 25 a signal S12 indicating the detection result of the charging voltage of the first smoothing capacitor.

[0076] In step SP33, the first control circuit 23 determines whether the charging voltage indicated by the signal S12 is less than a predetermined threshold value Vt2.

[0077] If the charging voltage indicated by the signal S12 is equal to or greater than the threshold value Vt2 (step SP33: NO), in step SP34 the first control circuit 23 determines whether a timeout has occurred because the elapsed time from the time the control signal S11 was output exceeds a predetermined upper limit value.

[0078] If the timeout has not occurred (step SP34: NO), the first control circuit 23 repeatedly executes the processes of steps SP33 and SP34.

[0079] If a timeout has occurred (step SP34: YES), in step SP35, first control circuit 23 inputs signal S15 indicating a malfunction of washing machine 1 to second control circuit 61. Second control circuit 61 displays an error message S25 indicating that washing machine 1 has broken down on display unit 63, thereby displaying an error message.

[0080] The charging voltage of the first smoothing capacitor gradually decreases after the start of discharging.

[0081] If the charging voltage indicated by the signal S12 is lower than the threshold value Vt2 (step SP33: YES), the first control circuit 23 starts the standby mode of the washing machine 1 in step SP36.

[0082] According to this embodiment, the phase detection circuit 24 detects the phase of the AC voltage V0 output by the AC power supply 11, and the first control circuit 23 causes the first switching circuit to conduct the first connection path 31 at the zero-cross timing of the AC voltage V0 based on the phase detected by the phase detection circuit 24. This makes it possible to suppress an inrush current that flows at the moment when the supply of drive power P1 from the AC power supply 11 to the load 12 starts.

[0083] 6 and 7, 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 when the control signal S14 is output until the conduction of the first connection path 31 is completed. This allows the timing at which the conduction of the first connection path 31 is completed to coincide with the zero-cross timing of the AC voltage V0 with high accuracy. As a result, the inrush current can be suppressed more effectively.

[0084] Furthermore, according to this embodiment, the first control circuit 23 causes the first switching circuit to conduct the first connection path 31 at the zero-cross timing after the charging voltage of the first smoothing capacitor becomes equal to or greater than the threshold value Vt1. This reduces the uncharged capacitance of the first smoothing capacitor at the moment when the first switching circuit causes the first connection path 31 to conduct. As a result, the inrush current can be suppressed more effectively.

[0085] Furthermore, according to this embodiment, the second smoothing capacitor included in the second rectifying and smoothing circuit 22 has a smaller capacitance than the first smoothing capacitor, and therefore the leakage current from the second smoothing capacitor can be suppressed more effectively than the first smoothing capacitor. As a result, even when the second rectifying and smoothing circuit 22 constantly drives the first control circuit 23, it is possible to suppress the power consumption of the washing machine 1.

[0086] Furthermore, according to this embodiment, in a standby state in which the first rectifying and smoothing circuit 21 and the load 12 are not driven, the power consumption of the washing machine 1 can be reduced while the second rectifying and smoothing circuit 22 continuously drives the first control circuit 23 and the second control circuit 61.

[0087] Furthermore, according to this embodiment, the second control circuit 61 can start driving the first rectifying smoothing circuit 21 and the load 12 by electronic control triggered by the acquisition of operation information from the start button 64.

[0088] Furthermore, according to this embodiment, the operation of the first rectifying smoothing circuit 21 and the load 12 can be started by electronic control triggered by the acquisition of remote control information from the communication circuit 62. Furthermore, in a standby state in which the communication circuit 62 is waiting to receive a remote control signal, the operation of the first rectifying smoothing circuit 21 and the load 12 is stopped, thereby reducing the power consumption of the washing machine 1.

[0089] (First Modification) FIG. 9 is a simplified diagram showing the circuit configuration of the washing machine 1 according to the first modification. In the washing machine 1 according to the first modification, the second rectifying and smoothing circuit 22, the second relay driving circuit 52, the communication circuit 62, the start button 64, the stop button 65, and the remote button 66 are omitted from the circuit configuration shown in FIG. 2. Also, a switch 70 such as a physical switch is provided instead of the second relay circuit 42 shown in FIG. 2. In the washing machine 1 according to the first modification, the standby mode and the remote control mode are omitted from the washing machine 1 according to the embodiment. Also, in the washing machine 1 according to the first modification, the constant drive function is omitted from the washing machine 1 according to the embodiment.

[0090] FIG. 10 is a flowchart showing a first operation that the washing machine 1 executes when the switch 70 is turned on while the power to the washing machine 1 is off.

[0091] When the user turns on switch 70 while washing machine 1 is powered off, second connection path 32 becomes conductive, 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. In addition, phase detection circuit 24 is activated.

[0092] The charging voltage of the first smoothing capacitor included in the first rectifying and smoothing circuit 21 gradually increases after charging starts, and when the charging voltage indicated by the signal S12 increases to a predetermined value or higher, the first control circuit 23 is activated.

[0093] In step SP41, the first control circuit 23 obtains from the phase detection circuit 24 the signal S13 indicating the detection result of the phase of the AC voltage V0.

[0094] In step SP42, the first control circuit 23 determines, based on the signal S13, whether or not the current time is the zero-cross timing of the AC voltage V0.

[0095] If the current time is not the zero-cross timing (step SP42: NO), the first control circuit 23 repeatedly executes the process of step SP42 at time intervals shorter than half the period of the waveform of the AC voltage V0.

[0096] If the current time is the zero-cross timing (step SP42: YES), in step SP43 the first control circuit 23 outputs a control signal S14 that instructs to close the first relay circuit 41. The control signal S14 output from the first control circuit 23 is input to the first relay drive circuit 51. The first relay drive circuit 51 closes the first relay circuit 41. As a result, the first connection path 31 becomes conductive, and the first smoothing capacitor is charged by a large charging current that is not limited by the current limiting resistor 26.

[0097] In step SP44, the washing machine 1 starts the operation mode.

[0098] FIG. 11 is a flowchart showing a second operation that the washing machine 1 executes when the switch 70 is turned on while the power to the washing machine 1 is off.

[0099] 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.

[0100] 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 detection result of the phase of the AC voltage V0 and the delay time in the first relay circuit 41. The first control circuit 23 calculates the delay time of the first relay circuit 41 implemented in the washing machine 1 based on the results of multiple past operations. The first control circuit 23 then calculates the timing that is the delay time of the first relay circuit 41 back from the next zero-crossing timing at the current time point as the control timing for outputting the control signal S14. Note that if the delay time of the first relay circuit 41 varies 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 results of the previous operation or the results of multiple most recent operations.

[0101] In step SP43, the first control circuit 23 outputs the control signal S14 instructing to close the first relay circuit 41 at the control timing calculated in step SP42A. As a result, the timing at which the conduction of the first connection path 31 is completed coincides with the next zero-cross timing from the current point in time.

[0102] According to this modification, similarly to the above embodiment, the phase detection circuit 24 detects the phase of the AC voltage V0 output by the AC power supply 11, and the first control circuit 23 causes the first switching circuit to conduct the first connection path 31 at the zero-cross timing of the AC voltage V0 based on the phase detected by the phase detection circuit 24. This makes it possible to suppress the inrush current that flows the moment the supply of drive power P1 from the AC power supply 11 to the load 12 starts, similarly to the above embodiment.

[0103] (Second Modification) In the above embodiment, the driving of the phase detection circuit 24 is stopped in the standby mode and the remote control mode. However, by using a phase detection circuit 24 with low power consumption, the phase detection circuit 24 may be driven at all times, including in the standby mode and the remote control mode.

[0104] In this case, when the control signal S10 instructing a transition from the standby mode or the remote control mode to the operation mode is input from the second control circuit 61, the first control circuit 23 acquires a signal S13 indicating the detection result of the phase of the AC voltage V0 from the phase detection circuit 24. In step SP11, the first control circuit 23 may input a control signal S11 instructing the second relay circuit 42 to be closed to the second relay drive circuit 52 at the zero-cross timing.

[0105] According to this modification, the first control circuit 23 causes the second switching circuit to make the second connection path 32 conductive at the zero-cross timing of the AC voltage V0, based on the phase detected by the phase detection circuit 24. This makes it possible to suppress the current that flows the moment the supply of drive power P1 from the AC power supply 11 to the load 12 starts, and to reduce the resistance value of the current-limiting resistor 26, thereby making it possible to reduce energy loss. [Industrial Applicability]

[0106] The present disclosure is widely applicable to top-loading washing machines, drum-type washing machines, and the like. [Explanation of symbols]

[0107] 1 washing machine 11 AC power supply 12 Load 13 Power supply control unit 14 Control section 21 1st rectifier smoothing circuit 22 2nd rectifier smoothing circuit 23 First control circuit 24 Phase detection circuit 25 Voltage detection circuit 26 Current limiting resistor 31 First connecting route 32 Second connecting route 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 section 64 Start button 65 Exit button 66 Remote Button 70 Switch

Claims

1. The load of performing laundry-related actions, a power supply control unit that controls the supply of drive power from an AC power supply to the load; Equipped with The power supply control unit a first rectifying and smoothing circuit including a first smoothing capacitor connected between the AC power supply and the load; a first switching circuit that switches between conduction and interruption of a first connection path that connects the AC power supply and the first rectifying and smoothing circuit; a phase detection circuit for detecting the phase of the AC voltage output by the AC power supply; a first control circuit; and 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; washing machine.

2. The first control circuit inputting a control signal to the first switching circuit to make the first connection path conductive; a timing for outputting the control signal is controlled based on the phase detected by the phase detection circuit and a delay time from when the control signal is output until when the conduction of the first connection path is completed. The washing machine according to claim 1.

3. a second switching circuit that switches between conduction and interruption of a second connection path that connects the AC power supply and the first rectifying and smoothing circuit via a current limiting resistor; a voltage detection circuit for detecting a charging voltage of the first smoothing capacitor; Furthermore, the first connection path connects the AC power supply and the first rectifying and smoothing circuit, bypassing the current limiting resistor; The first control circuit causing the second switching circuit to conduct the second connection path, thereby causing the AC power source to start charging the first smoothing capacitor; based on the charging voltage detected by the voltage detection circuit and the phase detected by the phase detection circuit, at the zero-cross timing after the charging voltage becomes equal to or greater than a threshold, causing the first switching circuit to make the first connection path conductive; The washing machine according to claim 1 or 2.

4. a second rectifying and smoothing circuit including a second smoothing capacitor connected between the AC power supply and the first control circuit and having a capacitance smaller than that of the first smoothing capacitor; The washing machine according to claim 3.

5. an operation unit having a second control circuit connected to the first control circuit; the power supply control unit supplies drive power from the AC power supply to the first control circuit and the second control circuit via the second rectifying and smoothing 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. The washing machine according to claim 4.

6. the operation unit further includes an operation button, the second control circuit inputs, to the first control circuit, a control signal that causes the second switching circuit to make the second connection path conductive by acquiring, from the operation button, operation information indicating that the operation button has been operated. The washing machine according to claim 5.

7. the operation unit further includes a communication circuit for receiving a remote operation signal; the communication circuit waits for reception of the remote control signal in the standby state; the second control circuit inputs, to the first control circuit, a control signal for causing the second switching circuit to make the second connection path conductive by acquiring, from the communication circuit, remote operation information indicating that the communication circuit has received the remote operation signal; The washing machine according to claim 5.

8. A method for controlling a washing machine comprising: a load that performs an operation related to washing; and a power supply control unit that controls supply of drive power from an AC power supply to the load, wherein the power supply control unit has: a first rectifying and smoothing circuit including a first smoothing capacitor connected between the AC power supply and the load; a first switching circuit that switches between conduction and interruption 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 an AC voltage output by the AC power supply; and a first control circuit, The first control circuit acquiring the phase detected by the phase detection circuit; making the first switching circuit conductive to the first connection path at a zero-cross timing of the AC voltage based on the acquired phase; How to control a washing machine.

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