Electromagnetic pump control system, method and household appliance

Abstract

The present invention relates to an electromagnetic pump control system, method and household appliance, including a processor and an output control circuit, wherein the processor is electrically connected to the output control circuit, and the processor is used to: obtain a zero-crossing signal in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero; perform timing according to the zero-crossing signal, output a trigger signal to the output control circuit according to the timing result, and control the electromagnetic pump to be turned on or off through the output control circuit; and control the output flow of the electromagnetic pump in the corresponding time period by changing the number of on-off times of the electromagnetic pump in different time periods. The technical solution of the present invention can control the output flow of the electromagnetic pump in different time periods, has low cost, small size, simple structure, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic pump control, and in particular to an electromagnetic pump control system, method and household appliance. Background Art

[0002] An electromagnetic pump is a device that uses an electromagnetic push rod to drive the diaphragm to reciprocate in the chamber, causing changes in the pressure in the chamber, which in turn causes the opening and closing of the suction valve and the discharge valve to achieve the suction and discharge of liquid. Among them, a micro electromagnetic pump is an electromagnet-driven plunger pump with the characteristics of small size, compact structure, high output pressure and strong sealing. The excellent characteristics of the micro electromagnetic pump make it widely used in small household appliances such as hanging irons. The product positioning of small household appliances such as hanging irons determines that the electromagnetic pump control system must be low-cost, small in size, stable and reliable, and have the function of regulating flow.

[0003] At present, the following methods are often used to control the flow of electromagnetic pumps:

[0004] The first method is to adjust the voltage of the pulsating power supply by changing the conduction angle of the thyristor, thereby achieving the purpose of flow regulation.

[0005] The second method is to directly use a voltage regulator to adjust the voltage to control the flow output.

[0006] Although both of the above methods can achieve stepless regulation of the flow of the electromagnetic pump, the control accuracy of the flow is low, and the hardware design requires the use of devices such as relays, which has high costs and energy consumption, and is not suitable for small household appliances such as hanging irons.

[0007] The third method is to control the output flow of the electromagnetic pump by adjusting the ratio of the on-time and off-time of the thyristor per unit time, and use the zero-point detection module to detect the zero-crossing signal obtained after the AC power is divided by a series resistor. Although this method can reduce costs, the zero-point detection module will be affected by the spike pulses of the power grid, resulting in false triggering problems, and thus abnormal flow control of the electromagnetic pump.

[0008] The fourth method is to control the output flow of the electromagnetic pump by adjusting the half-wave on-off of the cycle. The zero-crossing circuit obtains the zero-crossing signal by the voltage division of the series resistor of the mains, and uses the control method based on the query of the conductance table to control the on-off of the electromagnetic pump driving half-wave, thereby realizing the multi-gear regulation of the electromagnetic pump flow. However, the control method based on the query of the conductance table has high requirements on the stability and reliability of the system. Since the process of obtaining the zero-crossing signal by its zero-crossing circuit is also affected by the peak pulse of the power grid, it will also cause the control of the electromagnetic pump flow to be out of control.

[0009] In addition, the above-mentioned electromagnetic pump flow control methods can only control the on and off of the electromagnetic pump and control the electromagnetic pump to work at a predetermined output flow rate, and cannot further control the electromagnetic pump. However, when controlling the electromagnetic pump in a small household appliance, it is often necessary to control the output flow rate of the electromagnetic pump in time periods. For example: the working principle of a hanging iron is to transport water to a heating device through an electromagnetic pump, and the heating device heats the water to generate steam, so as to use the steam to iron clothes. Among them, during the use of the hanging iron, the heating device needs to be preheated first, and the electromagnetic pump needs to be turned off at this time to prevent the hanging iron from spraying water droplets. As time goes by, the heating device will reach the rated temperature, and ironing can be carried out at this time, but the output flow rate of the electromagnetic pump should not be too large, so as to prevent the heat generated by the heating device from being insufficient to completely vaporize the water. When the heating device reaches the rated temperature, the electromagnetic pump works at the rated output flow rate to speed up the ironing speed. Summary of the invention

[0010] In view of the above-mentioned deficiencies in the prior art, the present invention provides an electromagnetic pump control system, method and household appliance.

[0011] The technical solution of the present invention to solve the above technical problems is as follows:

[0012] In a first aspect, the present invention provides an electromagnetic pump control system, comprising an output control circuit and a processor, wherein the processor is electrically connected to the output control circuit, and the processor is used to:

[0013] A zero-crossing signal is obtained in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero.

[0014] Timing is performed according to the zero-crossing signal, and a trigger signal is output to the output control circuit according to the timing result, and the electromagnetic pump is controlled to be turned on or off through the output control circuit.

[0015] The output flow of the electromagnetic pump in the corresponding time period is controlled by changing the on-off times of the electromagnetic pump in different time periods.

[0016] In a second aspect, the present invention provides an electromagnetic pump control method, comprising:

[0017] A zero-crossing signal is obtained in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero.

[0018] Timing is performed according to the zero-crossing signal, and a trigger signal is output to the output control circuit according to the timing result, and the electromagnetic pump is controlled to be turned on or off through the output control circuit.

[0019] The output flow of the electromagnetic pump in the corresponding time period is controlled by changing the on-off times of the electromagnetic pump in different time periods.

[0020] In a third aspect, the present invention provides a household appliance, comprising the electromagnetic pump control system and the electromagnetic pump as described above, wherein the electromagnetic pump control system is electrically connected to the electromagnetic pump.

[0021] The beneficial effects of the electromagnetic pump control system, method and household appliance of the present invention are as follows: the processor can be a single chip microcomputer, etc., and the processor obtains the zero-crossing signal for timing. Since the time interval between two adjacent zero-crossing signals is fixed, the timing can be indirectly performed by counting the zero-crossing signals, and no timer is required, which can reduce the selection requirements for the processor and reduce the hardware cost of the control system. It can be determined whether the electromagnetic pump is controlled to be turned on at the current moment according to actual needs. In any time period, the output flow rate of the electromagnetic pump in the time period can be controlled by changing the number of times the electromagnetic pump is turned on and off. The technical solution of the present invention can control the output flow rate of the electromagnetic pump in different time periods, has low cost, small size, simple structure, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an electromagnetic pump control system according to an embodiment of the present invention;

[0023] Figure 2 A circuit diagram of an electromagnetic pump control system according to an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the control principle of an electromagnetic pump control system according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of a first isolation drive circuit of an electromagnetic pump control system according to an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of a second isolation drive circuit of an electromagnetic pump control system according to an embodiment of the present invention;

[0027] Figure 6 A schematic flow chart of an electromagnetic pump control method according to an embodiment of the present invention;

[0028] Figure 7 The figure is a waveform diagram of the voltage signal at both ends of the electromagnetic pump in different time periods according to an embodiment of the present invention.

[0029] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0030] 1. Control module, 10. Processor, 20. Output control circuit, 30. Zero-crossing detection circuit, 40. Power supply circuit, 201. Isolation drive circuit, 202. Protection circuit. DETAILED DESCRIPTION

[0031] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0032] like Figure 1 , Figure 2 As shown, an electromagnetic pump control system provided by an embodiment of the present invention includes a processor 10 and an output control circuit 20, wherein the processor 10 is electrically connected to the output control circuit 20, and the processor 10 is used to:

[0033] A zero-crossing signal is obtained in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero.

[0034] Specifically, the processor can be a single-chip microcomputer, which has low cost and small size. The AC power supply is used to power the entire control system and the electromagnetic pump. The mains power can be used as the AC power supply. The corresponding output AC power supply can be selected according to the actual input of the electromagnetic pump. The output voltage can be 220V or 380V, etc.

[0035] The DC power supply is used to power components such as the processor 10 , for example, outputting a 5V DC working voltage to the processor 10 to ensure that the processor 10 works normally.

[0036] Timing is performed according to the zero-crossing signal, and a trigger signal is output to the output control circuit 20 according to the timing result, and the electromagnetic pump is controlled to be turned on or off by the output control circuit 20.

[0037] Specifically, the trigger signal includes a trigger pulse, which is used to drive the electromagnetic pump to conduct. The time when the trigger pulse is output can be preset according to the actual situation. The time interval between two adjacent zero-crossing signals is fixed, and the timing is indirectly performed by counting the zero-crossing signals. No timer is required, which can reduce the selection requirements for the processor 10 and reduce the hardware cost of the control system. The output flow rate of the electromagnetic pump in the corresponding time period is controlled by changing the number of on and off times of the electromagnetic pump in different time periods.

[0038] Specifically, for example, when controlling the electromagnetic pump in a garment steamer, the working time of the electromagnetic pump can be divided into three time periods. The first 15 seconds is the first time period. During this time period, it is necessary to wait for the heating device in the garment steamer to preheat, so no trigger pulse is output and the electromagnetic pump does not work. 15 seconds to 40 seconds is the second time period. During this time period, the temperature of the heating device is about to reach the rated value, but has not yet reached the rated value. Therefore, a small amount of trigger pulses can be output to control the electromagnetic pump to work at a low output power to prevent the garment steamer from spraying water droplets. After 40 seconds is the third time period. During this time period, the temperature of the heating device reaches the rated value, so the rated number of trigger pulses can be output to control the electromagnetic pump to work at the rated power, thereby increasing the output flow of the electromagnetic pump.

[0039] In this embodiment, the processor can be a single-chip microcomputer, etc. The processor obtains the zero-crossing signal for timing. Since the time interval between two adjacent zero-crossing signals is fixed, the timing can be indirectly performed by counting the zero-crossing signals, and no timer is required, which can reduce the selection requirements for the processor and reduce the hardware cost of the control system. It can be determined whether to control the electromagnetic pump to be turned on at the current moment according to actual needs. In any time period, the output flow rate of the electromagnetic pump in the time period can be controlled by changing the number of times the electromagnetic pump is turned on and off. The technical solution of the present invention can control the output flow rate of the electromagnetic pump in different time periods, and has low cost, small size, simple structure, and broad application prospects.

[0040] Preferably, the system further comprises a zero-crossing detection circuit 30 electrically connected to the processor 10 , wherein the zero-crossing detection circuit 30 is used to perform zero-crossing sampling on the AC signal output by the AC power supply, obtain the zero-crossing signal, and transmit the zero-crossing signal to the processor 10 .

[0041] The zero-crossing detection circuit 30 includes a rectifier diode, namely Figure 2 In the figure, D1, a current limiting resistor, i.e., R1, a fuse, i.e., F1, a first optocoupler, i.e., U1, and a pull-down resistor, i.e., R2, the first optocoupler U1 is a transistor output type optocoupler, including a first optocoupler diode on the input side and a first transistor on the output side, a rectifier diode D1 is connected in series with the current limiting resistor R1, the positive electrode of the rectifier diode D1 is electrically connected to the neutral line N of the AC power supply, the negative electrode of the rectifier diode D1 is electrically connected to the positive electrode of the first optocoupler diode through the current limiting resistor R1, the negative electrode of the first optocoupler diode is electrically connected to the live line L of the AC power supply through the fuse F1, the collector of the first transistor is electrically connected to the VCC DC power supply, the emitter of the first transistor is electrically connected to the MCU_IO2 pin of the processor 10 and one end of the pull-down resistor R2 respectively, and the other end of the pull-down resistor R2 is grounded.

[0042] Specifically, the mains neutral line N is connected to the anode of the optocoupler diode in the first optocoupler U1 via a rectifier diode D1 and a current-limiting resistor R1, and the cathode of the optocoupler diode is connected to the mains live line L via a fuse F1. Since the rectifier diode D1 has a unidirectional conduction characteristic, the first optocoupler U1 is turned on during the negative half-wave of the mains and turned off during the positive half-wave. The two pins on the output side of the first optocoupler U1 are respectively connected to the MCU_IO2 pin and the VCC power supply, and the MCU_IO2 pin is also grounded via a pull-down resistor R5. When the transistor in the first optocoupler U1 is turned on, the MCU_IO2 pin of the processor 10 obtains a high level. When the transistor in the first optocoupler U1 is turned off, the MCU_IO2 pin obtains a low level, and the processor 10 captures the falling edge of the pulse as the positive zero-crossing point of the alternating current. Among them, the zero-crossing point is the moment corresponding to when the amplitude of the alternating current signal is zero, and the zero-crossing signal is the alternating current signal when the time is at the zero-crossing point. The zero-crossing point obtained by the processor 10 is actually an advanced zero-crossing point for the following reasons:

[0043] like Figure 3 As shown, based on the unidirectional conductivity of the optocoupler diode in the first optocoupler U1, the zero-crossing detection circuit 30 outputs a signal level that corresponds to the negative half-wave of the AC signal when it flips from a low level to a high level, i.e. Figure 3 At the moment t1, the on-off state of the optocoupler diode changes from cut-off to on-state. At this time, the AC mains changes from positive to negative, and the zero crossing point is the negative zero crossing point; ② When the high level turns to the low level, that is, Figure 3 At time t2, the on-off state of the optocoupler diode changes from on to off. At this time, the AC mains changes from negative to positive, and the zero crossing point is the positive zero crossing point. Since the optocoupler diode will only conduct when the input voltage is higher than the threshold voltage, the times t1 and t2 are not the real zero crossing points. The transistor on the output side of the optocoupler is directly turned off after the input voltage is lower than the threshold voltage. At this time, the real zero crossing point has not yet been reached, so the obtained positive zero crossing point (time t2) is actually ahead of the real zero crossing point (time t3).

[0044] In this preferred embodiment, the AC signal at the leading zero-crossing point on the negative half-wave of the AC signal is used as the zero-crossing signal. After the processor 10 obtains the zero-crossing signal, it immediately sends a wide pulse signal to trigger the unidirectional thyristor or optocoupler thyristor in the output control circuit 20. At this time, the unidirectional thyristor or optocoupler thyristor is in a reverse pressure state and remains turned off, and continues to output the trigger signal until the voltage at the terminal of the unidirectional thyristor or optocoupler thyristor transitions to a positive pressure, that is, when the time reaches the real zero-crossing point, the unidirectional thyristor or optocoupler thyristor is turned on, so that the electromagnetic pump works under the complete AC positive half-wave.

[0045] Compared with using an AC signal with a delayed zero-crossing moment as a zero-crossing signal, the solution of this embodiment can control the unidirectional thyristor or the optocoupler thyristor to be turned on at the actual zero-crossing moment, avoiding a phase shift gap in the driving half-wave signal that drives the electromagnetic pump, ensuring the integrity of the driving half-wave signal waveform, being more in line with the rated power supply mode of the electromagnetic pump, and reducing interference in the control system.

[0046] Moreover, the scheme of this embodiment has relatively low requirements on the closeness between the leading zero crossing point and the real zero crossing point. In the prior art, in order to ensure the control accuracy, it is necessary to make the leading zero crossing point as close to the real zero crossing point as possible. The closeness is affected by the size of the current limiting resistor R1 at the input end. Therefore, the selection of the current limiting resistor R1 is very strict. In this embodiment, it is only necessary to continuously output the trigger pulse for a long enough time until the unidirectional thyristor or the optocoupler thyristor is turned on according to the actual situation, so that the unidirectional thyristor or the optocoupler thyristor can be controlled to be turned on at the real zero crossing point. Therefore, the requirements for the closeness between the leading zero crossing point and the real zero crossing point are very low, which reduces the selection requirements for components. On this basis, when selecting the current limiting resistor R1, the resistance value of the current limiting resistor R1 can be appropriately increased, which can reduce the current, reduce the power consumption of the current limiting resistor R1, and extend the service life of the components in the control system.

[0047] The time interval between two adjacent leading zero-crossing points is used as the time base. This time interval is the industrial frequency cycle, that is, the frequency of the AC power. The industrial frequency cycle in my country is 20ms. Timing can be performed indirectly by counting the zero-crossing signals, and the working time periods can be distinguished according to the number of zero-crossing signals.

[0048] Preferably, the output control circuit 20 includes an isolation drive circuit 201 and a protection circuit 202, wherein the protection circuit 202 includes a freewheeling diode, that is, Figure 2 In the embodiment, D2 is connected to the AC power supply line L, and the positive electrode of the freewheeling diode D2 is electrically connected to the processor 10 through the isolation drive circuit 201, and the positive electrode of the freewheeling diode D2 is also electrically connected to the neutral line N of the AC power supply through the RC peak absorption circuit. The RC peak absorption circuit includes a first capacitor connected in series, namely C1, and a first resistor, namely R3. The positive electrode of the freewheeling diode D2 is also electrically connected to the negative electrode P- of the electromagnetic pump, and the negative electrode of the freewheeling diode D2 is electrically connected to the positive electrode P+ of the electromagnetic pump.

[0049] Specifically, C1 and R3 are connected in series to form a peak pulse absorption circuit, which can enhance the circuit's anti-interference performance. D2 is a freewheeling diode, connected to the P+ and P- ends of the electromagnetic pump interface, and is used to provide a freewheeling circuit when the unidirectional thyristor or optocoupler thyristor is turned off, reducing the impact of the electromagnetic pump's inductive load on the circuit.

[0050] Preferably, the isolation driving circuit 201 includes a first isolation driving circuit and / or a second isolation driving circuit.

[0051] The first isolation driving circuit includes a second optical coupler, namely Figure 4U2 in the figure, the second optocoupler U2 is a unidirectional thyristor output optocoupler, the unidirectional thyristor output optocoupler includes an optocoupler diode on the optocoupler input side and an optocoupler thyristor on the optocoupler output side, a second resistor, namely R4, and a first pull-up resistor, namely R5, the anode of the second optocoupler diode is connected to the VCC DC power supply via the first pull-up resistor R5, the cathode of the second optocoupler diode is electrically connected to the MCU_IO2 pin of the processor 10, the anode of the optocoupler thyristor in the second optocoupler U2 is electrically connected to the negative electrode P- of the electromagnetic pump, the cathode of the optocoupler thyristor of the second optocoupler U2 is electrically connected to the neutral line N of the mains, and the control electrode of the optocoupler thyristor of the second optocoupler U2 is connected to the neutral line of the mains through the second resistor R4.

[0052] Specifically, the resistor R4 is connected to the neutral line N to set the conduction angle of the optocoupler thyristor to 0°. The I / O port of the processor 10 is connected to the input end of the second optocoupler U2 after being pulled up, and the optocoupler thyristor at the output side of the second optocoupler U2 is triggered to conduct by the wide pulse signal sent by the processor 10. The optocoupler thyristor is a unidirectional thyristor. Due to the unidirectional conductivity of the unidirectional thyristor, the first isolation drive circuit 201 is only turned on in the positive half-wave of the AC to drive the electromagnetic pump to work.

[0053] In this preferred embodiment, the anode of the optocoupler diode in the output control circuit 20 is connected to the VCC power supply through the pull-up resistor R5, and the cathode is connected to the MCU_IO3 pin. The mains neutral line N is connected to the cathode of the optocoupler thyristor, and the anode of the optocoupler thyristor is connected to the P- interface of the electromagnetic pump. The P+ interface is then connected to the mains live line L through the circuit protection part. This circuit is the electromagnetic pump drive circuit. When the isolated output control circuit 20 receives the trigger signal sent by the processor 10, the input side of the second optocoupler U2 is turned on, and at this time, Figure 3 At t2 in the figure, since the AC is in the negative half-wave cycle, the optocoupler thyristor on the output side of U2 is subjected to reverse voltage and is still in the off state. At t3, the trigger pulse on the optocoupler input side still maintains a low level, and the thyristor is directly turned on after being subjected to positive voltage. After that, even if the trigger signal disappears, the thyristor is still in the positive voltage state and will continue to be turned on until it is turned off after being subjected to reverse voltage at t4.

[0054] The second isolation driving circuit includes a third optical coupler, namely Figure 5In U3, the third optocoupler U3 is a transistor output optocoupler, which includes a third optocoupler diode on the optocoupler input side and a second transistor on the optocoupler output side, and also includes a second pull-up resistor, i.e., R8, a third resistor, i.e., R9, a fourth resistor, i.e., R10, and a unidirectional thyristor D8. The positive electrode of the third optocoupler diode is connected to the VCC DC power supply via the second pull-up resistor R8, the negative electrode of the third optocoupler diode is electrically connected to the MCU_IO3 pin of the processor 10, the collector of the second transistor is electrically connected to the VCC power supply, and the third resistor R9 and the fourth resistor R10 are connected in series between the emitter of the second transistor and the ground in sequence. The control electrode of the unidirectional thyristor D8 is connected between the third resistor R9 and the fourth resistor R10, the cathode of the unidirectional thyristor D8 is electrically connected to the neutral line N of the mains, and the anode of the unidirectional thyristor D8 is electrically connected to the negative electrode P- of the electromagnetic pump.

[0055] Specifically, the I / O port of the processor 10 is connected to the input end of the third optocoupler U3 after being pulled up, and the anode of the optocoupler diode on the input side of the third optocoupler U3 is connected to the VCC power supply by the pull-up resistor R8, and the cathode is connected to the MCU_IO3 pin. The anode of the second transistor on the output side of the third optocoupler U3 is connected to the VCC DC power supply through the pull-up resistor R8, and the cathode is grounded through two voltage-dividing resistors R9 and R10. The unidirectional thyristor D8 is connected in series with the electromagnetic pump to play the role of rectification and controlling the on and off of the electromagnetic pump. The control electrode of the unidirectional thyristor D8 is connected between the two voltage-dividing resistors R9 and R10, thereby obtaining a trigger signal for controlling the on and off of the unidirectional thyristor D8 output by the processor 10. When the processor 10 sends a trigger pulse, the optocoupler transistor of the third optocoupler U3 is turned on, and the unidirectional thyristor D8 is turned on immediately after the time reaches the real zero crossing point, and the electromagnetic pump obtains a positive half-wave drive signal. The cathode of the unidirectional thyristor D8 is connected to the mains neutral line N, and the anode is connected to the electromagnetic pump P- interface. The electromagnetic pump P+ interface is then connected to the mains live line L through the protection circuit. This circuit is the electromagnetic pump drive circuit.

[0056] When the processor 10 sends a trigger signal, the input side of the third optical coupler U3 is turned on, and the output side is also turned on immediately, and the unidirectional thyristor D8 obtains a conduction signal, corresponding to Figure 3 At time t2, the AC signal is in the negative half-wave cycle, and the thyristor D8 is under reverse pressure and is still in the off state. At time t3, since the trigger signal is still a low-level wide pulse signal, the thyristor D8 conduction signal still exists, and the thyristor D8 is directly turned on when the AC signal switches to the positive half-wave cycle and bears positive pressure. At time t4, the AC signal enters the negative half-wave cycle again, and the thyristor D8 is under reverse pressure again and is turned off.

[0057] In this preferred embodiment, the output control circuit 20 utilizes the isolation characteristics of the optocoupler device to effectively prevent the false triggering problem that exists when the processor pin directly controls the unidirectional thyristor or the optocoupler thyristor, while at the same time being able to isolate the interference to the control system caused by the on and off moments of the electromagnetic pump and the AC half-wave asymmetric power supply method, thereby increasing the stability of the system.

[0058] Preferably, a substrate is further included, on which the zero-crossing detection circuit 30 , the processor 10 and the isolation drive circuit 201 are all arranged, and all circuits on the substrate are packaged into thick film circuits.

[0059] Specifically, each part of the control system can be processed in a modular form, and the zero-crossing detection circuit 30, the processor 10 and the drive isolation control circuit are combined into a control module 1, which is integrated on a substrate. The substrate can be a glass substrate and a ceramic substrate, etc., and the circuit on the control module 1 is packaged into a thick film circuit. The thick film circuit refers to an integrated circuit composed of a passive network made by using an array film process (silk screen printing, sintering and electroplating, etc.) on the same substrate and assembled with discrete semiconductor devices, monolithic integrated circuits or micro components. At the same time, the remaining circuits are integrated on the baseboard, and the control module 1 is connected to the baseboard to form a control system.

[0060] In this preferred embodiment, the circuit in the control module 1 is packaged into a thick film circuit, which can make it waterproof and dustproof and extend its service life.

[0061] Preferably, it also includes a power supply circuit 40 for power supply, and the power supply circuit 40 includes a fifth resistor, that is, Figure 2 R6, the sixth resistor, i.e. R7, the second capacitor, i.e. C3, the third capacitor, i.e. C5, the polarity capacitor, i.e. C4, the first diode, i.e. D3, the second diode, i.e. D4, the Zener diode, i.e. D5, and the light emitting diode, i.e. D6.

[0062] The fifth resistor R6 is connected in parallel with the second capacitor C3, one end of the second capacitor C3 is electrically connected to the live wire L of the mains, and is also electrically connected to the neutral line N of the mains through the third capacitor C5. The other end of the second capacitor C3 is electrically connected to the positive electrode of the first diode D3 and the negative electrode of the second diode D4 respectively, the positive electrode of the second diode D4 is electrically connected to the neutral line N of the mains, the negative electrode of the first diode D3 is electrically connected to the negative electrode of the Zener diode D5, the positive electrode of the Zener diode D5 is electrically connected to the neutral line N of the mains, the positive electrode of the polarity capacitor C4 is electrically connected to the negative electrode of the Zener diode D5, and is used as the DC power supply, i.e., the VCC power supply. The negative electrode of the polarity capacitor C4 is grounded and electrically connected to the positive electrode of the Zener diode D5. The positive electrode of the polarity capacitor C4 is also electrically connected to the positive electrode of the light-emitting diode D6, and the negative electrode of the light-emitting diode D6 is electrically connected to the MCU_IO1 pin of the processor 10 through the sixth resistor R7.

[0063] Specifically, firstly, a step-down circuit composed of a fifth resistor R6 and a second capacitor C3 in parallel is used to draw power from the AC220V mains, and then the VCC DC power supply required by the control system is obtained by relying on the voltage regulator diode D5 after rectification and filtering by the first diode D3 and the polar capacitor C4. The second diode D4 is a freewheeling diode, which is used to form a circuit with the first diode D3 and the voltage regulator diode D5 to discharge the excess current of the constant current source VCC power supply when the load fluctuates. However, if the current is too large and exceeds the maximum stable current of the voltage regulator diode D5, it will cause permanent damage to the voltage regulator diode D5, thereby causing a power supply circuit failure. Therefore, the constant current compensation circuit described below is designed in this application to reduce the impact of load fluctuations on the VCC DC power supply, wherein the output end of the power supply circuit 40, that is, the VCC power supply in the figure is connected to the MCU_IO1 pin of the processor 10 via the light-emitting diode D6 and the resistor R7 to form a constant current compensation circuit. The processor 10 is used to control the on-off state of the constant current compensation circuit so that it is complementary to the working state of the optocoupler diode on the input side of the second optocoupler U2 or the third optocoupler U3 in the output control circuit 20. The sixth resistor R7 is used to adjust the current when the compensation circuit is turned on to make it consistent with the input current when the optocoupler diode on the input side of the second optocoupler U2 or the third optocoupler U3 is turned on, so as to reduce the impact of load fluctuations on the VCC power supply as much as possible.

[0064] like Figure 6 As shown, an electromagnetic pump control method provided by an embodiment of the present invention includes:

[0065] 110. Obtain a zero-crossing signal in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero.

[0066] 120 , timing is performed according to the zero-crossing signal, and a trigger signal is output to an output control circuit according to the timing result, and the electromagnetic pump is controlled to be turned on or off through the output control circuit.

[0067] 130. Control the output flow of the electromagnetic pump in the corresponding time period by changing the number of times the electromagnetic pump is turned on and off in different time periods.

[0068] Preferably, the specific implementation of obtaining the zero-crossing signal in the AC signal output by the AC power supply is:

[0069] The zero-crossing signal in the AC signal output by the AC power supply is obtained by the zero-crossing detection circuit 30 . The zero-crossing detection circuit 30 performs zero-crossing sampling on the AC signal by using an optocoupler isolation method to obtain the zero-crossing signal.

[0070] Preferably, the time point corresponding to when the amplitude of the AC signal is zero is the real zero-crossing point, timing is performed according to the zero-crossing signal, a trigger signal is output to the output control circuit according to the timing result, and the electromagnetic pump is controlled to be turned on or off by the output control circuit, specifically comprising the following steps:

[0071] The zero-crossing signal is counted to obtain a counting result.

[0072] The time interval between two adjacent zero-crossing signals is used as a time base, and timing is performed in combination with the counting result to obtain a timing result.

[0073] The working mode corresponding to the timing result is determined in a preset working mode according to the timing result, wherein the working mode corresponds to the trigger signal, and the corresponding trigger signal is output to the output control circuit according to the working mode, and the trigger signal includes a trigger pulse.

[0074] The trigger pulse is output at a leading zero crossing point that is ahead of the actual zero crossing point, and the unidirectional thyristor or optocoupler thyristor in the output control circuit is controlled to be turned on at the actual zero crossing point according to the trigger pulse to control the electromagnetic pump to be turned on.

[0075] Specifically, the leading zero-crossing point is the time before the actual zero-crossing point, e.g. Figure 3 At time t2, the processor outputs different numbers of trigger pulses in different time periods to control the corresponding number of times the electromagnetic pump is turned on, thereby controlling the output flow of the electromagnetic pump.

[0076] In this preferred embodiment, a trigger pulse is output at the time of advancing the zero-crossing point, which can control the unidirectional thyristor or the optocoupler thyristor to be turned on at the actual zero-crossing point, thereby avoiding the phase shift gap in the driving half-wave signal that drives the electromagnetic pump to work, ensuring the integrity of the driving half-wave signal waveform, being more in line with the rated power supply mode of the electromagnetic pump, and reducing interference in the control system.

[0077] like Figure 7As shown, taking the control method of the electromagnetic pump in the garment steamer as an example, in this example, the counting result is directly used as the basis for judging the working mode. The program is simple, fast and convenient. The processor 10 will enter a functional subroutine every time it detects a positive zero crossing. After entering the subroutine, first the counter value CNT is increased by 1, and then it is determined whether CNT is less than 750 (the frequency of my country's power grid is 50Hz, and 15s can count 15×50 times. The time period can be set according to actual needs). If so, it enters the S00 working mode, and the MCU_IO3 pin maintains the default output high level, and does not send a trigger pulse, so that the electromagnetic pump does not work within the first 15s after starting. If CNT is not less than 750, it continues to determine whether CNT is greater than or equal to 750 and less than 2000 (that is, 15s to 40s after starting). If so, it enters the S01 working mode: the MCU_IO3 pin sends a low-level wide pulse signal to trigger the conduction of 2 electromagnetic pump drive half waves, and then turns off 4 half waves. If it is judged that CNT is greater than or equal to 2000 (40s after starting), it enters the S02 working mode: a pulse signal is sent to turn on two electromagnetic pump drive half waves and then turn off two half waves. At the same time, the MCU_IO1 pin is used to control the on-off of the constant current compensation circuit. Every time the MCU_IO3 pin sends a low-level trigger pulse, the output level of the MCU_IO1 pin will change from low to high. After a delay of 3ms, the two pins are reset at the same time. This ensures that the on-off state of the optocoupler diode on the input side of the second optocoupler U2 or the third optocoupler U3 in the output circuit is complementary to the on-off state of the constant current compensation circuit, so that the total load current remains unchanged, reducing the impact of the load current on the power supply circuit 40.

[0078] An embodiment of the present invention provides a household appliance, comprising the electromagnetic pump control system and the electromagnetic pump as described above, wherein the electromagnetic pump control system is electrically connected to the electromagnetic pump. The household appliance may be a garment steamer, etc. The garment steamer comprises a steam heater, a water tank, an electromagnetic pump, an electromagnetic pump control system, a steam nozzle, and a steam conduit, etc. The water tank is connected to the steam nozzle through the steam conduit, the steam heater is used to heat the water in the water tank into high-temperature, high-pressure water vapor, and the steam is output from the steam nozzle through the steam conduit to iron clothes, the electromagnetic pump control system is used to control the electromagnetic pump, and the electromagnetic pump is arranged in the steam generator to control the flow rate of the steam generated by the steam generator.

[0079] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0080] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0081] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0082] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0083] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0084] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electromagnetic pump control system, characterized in that: The device comprises a processor and an output control circuit, wherein the processor is electrically connected to the output control circuit, and the processor is used to: Acquire a zero-crossing signal in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero, and the AC signal at the leading zero point on the negative half-wave of the AC signal is used as the zero-crossing signal; Perform timing according to the zero-crossing signal, output a trigger signal to the output control circuit according to the timing result, and control the electromagnetic pump to be turned on or off through the output control circuit; Controlling the output flow of the electromagnetic pump in the corresponding time period by changing the number of on and off times of the electromagnetic pump in different time periods; The system further comprises a zero-crossing detection circuit electrically connected to the processor, wherein the zero-crossing detection circuit is used to perform zero-crossing sampling on the AC signal output by the AC power supply, obtain the zero-crossing signal, and transmit the zero-crossing signal to the processor; The zero-crossing detection circuit includes a rectifier diode, a current-limiting resistor, a fuse, a first optocoupler and a pull-down resistor, wherein the first optocoupler is a transistor output type optocoupler, including a first optocoupler diode on the input side and a first transistor on the output side, the positive electrode of the rectifier diode is electrically connected to the neutral line of the AC power supply, the negative electrode of the rectifier diode is electrically connected to the positive electrode of the first optocoupler diode through the current-limiting resistor, the negative electrode of the first optocoupler diode is electrically connected to the live line of the AC power supply through the fuse, the collector of the first transistor is electrically connected to the DC power supply, the emitter of the first transistor is electrically connected to the processor and one end of the pull-down resistor respectively, and the other end of the pull-down resistor is grounded; The output control circuit includes an isolation drive circuit and a protection circuit, the protection circuit includes a freewheeling diode and an RC peak absorption circuit, the cathode of the freewheeling diode is electrically connected to the live wire of the AC power supply, the anode of the freewheeling diode is electrically connected to the processor through the isolation drive circuit, the anode of the freewheeling diode is also electrically connected to the neutral wire of the AC power supply through the RC peak absorption circuit, the RC peak absorption circuit includes a first capacitor and a first resistor connected in series, the anode of the freewheeling diode is also electrically connected to the cathode of the electromagnetic pump, and the cathode of the freewheeling diode is electrically connected to the anode of the electromagnetic pump; The isolation driving circuit includes a first isolation driving circuit or a second isolation driving circuit; The first isolation driving circuit includes a second optocoupler, a first pull-up resistor and a second resistor, wherein the second optocoupler is a unidirectional thyristor output type optocoupler, including a second optocoupler diode on the input side and an optocoupler thyristor on the output side, the anode of the second optocoupler diode is connected to the DC power supply via the first pull-up resistor, the cathode of the second optocoupler diode is electrically connected to the processor, the anode of the optocoupler thyristor is electrically connected to the cathode of the electromagnetic pump, the cathode of the optocoupler thyristor is electrically connected to the neutral line of the AC power supply, and the control electrode of the optocoupler thyristor is connected to the neutral line of the AC power supply via the second resistor; The second isolation drive circuit includes a third optocoupler, a second pull-up resistor, a third resistor, a fourth resistor and a unidirectional thyristor, wherein the third optocoupler is a transistor output type optocoupler, including a third optocoupler diode on the input side and a second transistor on the output side, the positive electrode of the third optocoupler diode is connected to the DC power supply via the second pull-up resistor, the negative electrode of the third optocoupler diode is electrically connected to the processor, the positive electrode of the second transistor is electrically connected to the DC power supply, the third resistor and the fourth resistor are connected in series between the negative electrode of the second transistor and the ground in sequence, the control electrode of the unidirectional thyristor is connected between the third resistor and the fourth resistor, the cathode of the unidirectional thyristor is electrically connected to the neutral line of the AC power supply, and the anode of the unidirectional thyristor is electrically connected to the negative electrode of the electromagnetic pump.

2. The electromagnetic pump control system according to claim 1, characterized in that: It also includes a substrate, and the zero-crossing detection circuit, the processor and the isolation drive circuit are all arranged on the substrate.

3. The electromagnetic pump control system according to claim 1, characterized in that: The system further comprises a power supply circuit for supplying power, wherein the power supply circuit comprises a fifth resistor, a sixth resistor, a second capacitor, a third capacitor, a polarity capacitor, a first diode, a second diode, a voltage stabilizing diode and a light emitting diode; The fifth resistor is connected in parallel with the second capacitor, one end of the second capacitor is electrically connected to the live wire of the AC power supply, and is electrically connected to the neutral wire of the AC power supply through the third capacitor, the other end of the second capacitor is electrically connected to the positive electrode of the first diode and the negative electrode of the second diode respectively, the positive electrode of the second diode is electrically connected to the neutral wire of the AC power supply, the negative electrode of the first diode is electrically connected to the negative electrode of the Zener diode, the positive electrode of the Zener diode is electrically connected to the neutral wire of the AC power supply, the positive electrode of the polarity capacitor is electrically connected to the negative electrode of the Zener diode and is used as the DC power supply, the negative electrode of the polarity capacitor is grounded and electrically connected to the positive electrode of the Zener diode, the positive electrode of the polarity capacitor is also electrically connected to the positive electrode of the light-emitting diode, and the negative electrode of the light-emitting diode is electrically connected to the processor through the sixth resistor.

4. An electromagnetic pump control method, applied to the electromagnetic pump control system according to any one of claims 1 to 3, characterized in that: include: Acquire a zero-crossing signal in an AC signal output by an AC power supply, wherein the zero-crossing signal is a signal when the amplitude of the AC signal is zero, and the AC signal at the leading zero point on the negative half-wave of the AC signal is used as the zero-crossing signal; Perform timing according to the zero-crossing signal, output a trigger signal to an output control circuit according to the timing result, and control the electromagnetic pump to be turned on or off through the output control circuit; Controlling the output flow of the electromagnetic pump in the corresponding time period by changing the number of on and off times of the electromagnetic pump in different time periods; The specific implementation of obtaining the zero-crossing signal in the AC signal output by the AC power supply is: The zero-crossing signal in the AC signal output by the AC power supply is obtained through a zero-crossing detection circuit, wherein the zero-crossing detection circuit performs zero-crossing sampling on the AC signal by an optocoupler isolation method to obtain the zero-crossing signal.

5. The electromagnetic pump control method according to claim 4, characterized in that: The time point corresponding to when the amplitude of the AC signal is zero is the real zero-crossing point, timing is performed according to the zero-crossing signal, a trigger signal is output to the output control circuit according to the timing result, and the electromagnetic pump is controlled to be turned on or off by the output control circuit, specifically comprising the following steps: Counting the zero-crossing signals to obtain a counting result; Taking the time interval between two adjacent zero-crossing signals as a time base and combining the counting result to perform timing, thereby obtaining a timing result; Determine the working mode corresponding to the timing result in a preset working mode according to the timing result, wherein the working mode corresponds to the trigger signal, and output the corresponding trigger signal to the output control circuit according to the working mode, wherein the trigger signal includes a trigger pulse; The trigger pulse is output at a leading zero crossing point that is ahead of the actual zero crossing point, and the unidirectional thyristor or optocoupler thyristor in the output control circuit is controlled to be turned on at the actual zero crossing point according to the trigger pulse to control the electromagnetic pump to be turned on.

6. A household appliance, characterized in that: The invention comprises an electromagnetic pump control system and an electromagnetic pump as claimed in any one of claims 1 to 3, wherein the electromagnetic pump control system is electrically connected to the electromagnetic pump.

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