Starting control circuit and household appliance

Abstract

The utility model discloses a starting control circuit and a household appliance. The starting control circuit comprises a zero-cross detection branch circuit, a controller, a switch branch circuit, a silicon controlled rectifier and an energy storage branch circuit. The zero-crossing detection branch outputs a zero-crossing signal to the controller based on a zero-crossing point of the AC power supply, and the AC power supply is a sine wave. The controller determines zero-crossing points of the AC power supply based on the zero-crossing signals and outputs a pulse based on each zero-crossing point, and the starting time of each pulse is earlier than the time of the corresponding zero-crossing point. The switch branch is turned on in response to a pulse to establish a connection between the first power supply and the control terminal of the silicon controlled rectifier. The silicon controlled rectifier is switched on when being connected with the first power supply so as to establish connection between the second end of the energy storage branch and the second end of the alternating current power supply, and is switched off when the alternating current power supply is at a zero crossing point. The energy storage branch is charged by the AC power supply to store energy when the silicon controlled rectifier is conducted. Through the mode, the reliability and the stability can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electronic circuits, and in particular to a startup control circuit and a household appliance. Background Art

[0002] The start control circuit is used to control and manage the start, stop and operation process of household appliances such as refrigerators and washing machines to ensure that the household appliances can operate safely, stably and efficiently.

[0003] The existing startup control circuit is usually implemented by a relay. When the household appliance is started, the normally open contact of the relay is closed to charge the subsequent electrolytic capacitor through the AC power supply, and then power other loads to achieve normal operation of the household appliance.

[0004] However, when the normally open contacts of the relay are closed, the AC power supply may be at a higher voltage. At this time, a large surge current will be generated when the AC power supply charges the electrolytic capacitor, which may cause damage to the device and poor stability and reliability. Utility Model Content

[0005] The embodiments of the present application provide a startup control circuit and a household appliance, which can improve reliability and stability.

[0006] In a first aspect, an embodiment of the present application provides a startup control circuit, including:

[0007] Zero-crossing detection branch, controller, switch branch, thyristor and energy storage branch;

[0008] The zero-crossing detection branch is connected to the AC power supply and is configured to output a zero-crossing signal to the controller based on a zero-crossing point of the AC power supply, wherein the AC power supply is a sine wave;

[0009] The controller is connected to the zero-crossing detection branch and is configured to determine the zero-crossing point of the AC power supply based on the zero-crossing signal, and output a pulse based on each zero-crossing point, wherein the start time of each pulse is earlier than the time of the corresponding zero-crossing point;

[0010] The switch branch is connected to the controller and connected between the first power source and the control terminal of the thyristor, and is configured to be turned on in response to the pulse to establish a connection between the first power source and the control terminal of the thyristor;

[0011] The thyristor is connected between the second end of the energy storage branch and the second end of the AC power supply, is configured to be turned on when it is connected to the first power supply to establish a connection between the second end of the energy storage branch and the second end of the AC power supply, and is configured to be turned off when the AC power supply is at a zero-crossing point, wherein the first end of the energy storage branch is connected to the first end of the AC power supply;

[0012] The energy storage branch is configured to be charged by the AC power source to store energy when the thyristor is turned on.

[0013] In one or more embodiments, the startup control circuit further includes:

[0014] The first signal processing branch is connected to the switch branch and the control end of the thyristor respectively, and is configured to filter the first power supply and limit the current between the switch branch and the control end of the thyristor.

[0015] In one or more embodiments, the startup control circuit further includes:

[0016] The second signal processing branch is connected to the AC power supply, the thyristor and the energy storage branch respectively, and is configured to filter and rectify the AC power supply and then input it into the energy storage branch to charge the energy storage branch when the thyristor is turned on.

[0017] In one or more embodiments, the zero-crossing detection branch includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a first capacitor, a second capacitor and a first switch tube;

[0018] The first resistor and the second resistor are connected in series between the first end of the AC power supply and the ground, the connection point between the first resistor and the second resistor is connected to the first end of the first switch tube, the second end of the first switch tube is connected to the ground, the first capacitor is connected in parallel with the first resistor, the anode of the first diode is connected to the first end of the first switch tube, and the cathode of the first diode is connected to the ground, the third resistor and the fourth resistor are connected in series between the controller and the first power supply, the connection point between the third resistor and the fourth resistor is connected to the third end of the first switch tube, and the third resistor and the fourth resistor are connected in series and then connected in parallel with the second capacitor.

[0019] In one or more embodiments, the switch branch includes a fifth resistor, a sixth resistor and a second switch tube;

[0020] The fifth resistor and the sixth resistor are connected in series between the controller and the first power supply, the connection point between the fifth resistor and the sixth resistor is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the first power supply, and the third end of the second switch tube is connected to the control end of the thyristor.

[0021] In one or more embodiments, the energy storage branch includes a third capacitor;

[0022] The third capacitor is connected between the first terminal and the second terminal of the AC power source.

[0023] In one or more embodiments, the first signal processing branch includes a seventh resistor, an eighth resistor and a fourth capacitor;

[0024] The seventh resistor is connected between the switch branch and the control end of the thyristor, the fourth capacitor is connected between the second end of the AC power supply and the control end of the thyristor, and the eighth resistor is connected in parallel with the fourth capacitor.

[0025] In one or more embodiments, the second signal processing branch includes an inductor and a rectifier bridge;

[0026] The first end of the inductor is connected to the first end of the AC power supply, the second end of the inductor is connected to the first end of the rectifier bridge, the second end of the rectifier bridge is connected to the first end of the energy storage branch, the third end of the rectifier bridge is connected to the ground, the fourth end of the rectifier bridge is connected to the third end of the inductor, the fourth end of the inductor is connected to the second end of the thyristor non-control end, and the first end of the thyristor non-control end is connected to the second end of the AC power supply.

[0027] In one or more embodiments, the startup control circuit further includes a first interface and a second interface;

[0028] The first end of the first interface is connected to the first end of the AC power supply, the second end of the first interface is connected to the second end of the AC power supply through the thyristor, the first end of the second interface is connected to the first end of the second signal processing branch, and the second end of the second interface is connected to the second end of the second signal processing branch;

[0029] The first end of the first interface is used to connect to the first end of the second interface, and the second end of the first interface is used to connect to the second end of the second interface.

[0030] In a second aspect, an embodiment of the present application provides a household appliance, comprising the startup control circuit as described above.

[0031] The beneficial effects of the present application are as follows: the startup control circuit of the embodiment of the present application includes a zero-crossing detection branch, a controller, a switch branch, a thyristor and an energy storage branch. Wherein, the zero-crossing detection branch is connected to the AC power supply, and is configured to output a zero-crossing signal to the controller based on the zero-crossing point of the AC power supply, and the AC power supply is a sine wave. The controller is connected to the zero-crossing detection branch, and is configured to determine the zero-crossing point of the AC power supply based on the zero-crossing signal, and output a pulse based on each zero-crossing point, wherein the start time of each pulse is earlier than the corresponding zero-crossing point. The switch branch is connected to the controller, and is connected between the first power supply and the control end of the thyristor, and is configured to be turned on in response to the pulse to establish a connection between the first power supply and the control end of the thyristor. The thyristor is connected between the second end of the energy storage branch and the second end of the AC power supply, and is configured to be turned on when it is connected to the first power supply to establish a connection between the second end of the energy storage branch and the second end of the AC power supply, and is configured to be turned off when the AC power supply is at the zero-crossing point, wherein the first end of the energy storage branch is connected to the first end of the AC power supply. The energy storage branch is configured to be charged by the AC power supply and store energy when the thyristor is turned on. When the household appliance including the start-up control circuit is started, the controller can configure the start time of the pulse output by it to be close to the corresponding zero-crossing time, so that the time when the thyristor is turned on is close to the corresponding zero-crossing time. In this case, the AC power supply is at a lower voltage position when the thyristor is turned on. It can be seen that compared with the solution using relays in the related art, the embodiment of the present application has a smaller surge current generated when the AC power supply charges the energy storage branch because the AC power supply is at a lower voltage position when the thyristor is turned on, resulting in a smaller risk of device damage, thereby improving stability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0033] Figure 1 This is a schematic diagram of the structure of the startup control circuit provided in the embodiment of the present application. Figure 1 ;

[0034] Figure 2 is a schematic diagram of an AC power supply and a pulse provided in an embodiment of the present application;

[0035] Figure 3 This is a schematic diagram of the structure of the startup control circuit provided in the embodiment of the present application. Figure 2 ;

[0036] Figure 4 This is a schematic diagram of the structure of the startup control circuit provided in the embodiment of the present application. Figure 3 ;

[0037] Figure 5 The circuit structure of the startup control circuit provided in the embodiment of the present application is shown in FIG. Figure 1 ;

[0038] Figure 6 The circuit structure of the startup control circuit provided in the embodiment of the present application is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] It should be noted that, when an element is described as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0041] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0042] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the startup control circuit provided in the embodiment of the present application. Figure 1 As shown, the startup control circuit 100 includes a zero-crossing detection branch 10 , a controller 20 , a switch branch 30 , a thyristor DW1 and an energy storage branch 40 .

[0043] The zero-crossing detection branch 10 is connected to the AC power source 200. The controller 20 is connected to the zero-crossing detection branch. The switch branch 30 is connected to the controller 20 and is connected between the first power source V1 and the control end of the thyristor DW1. The thyristor DW1 is connected between the second end of the energy storage branch and the second end of the AC power source 200. The first end of the energy storage branch 40 is connected to the first end of the AC power source 200.

[0044] Specifically, the first end of the zero-crossing detection branch 10 is connected to the first end of the AC power supply 200 and the first end of the energy storage branch 40 respectively, the second end of the zero-crossing detection branch 10 is connected to the controller 20, the first end of the switch branch 30 is connected to the controller 20, the second end of the switch branch 30 is connected to the first power supply V1, the third end of the switch branch 30 is connected to the control end of the thyristor DW1, the first end of the non-control end of the thyristor DW1 is connected to the second end of the energy storage branch, and the second end of the non-control end of the thyristor DW1 is connected to the second end of the AC power supply 200.

[0045] Wherein, the zero-crossing detection branch 10 is configured to output a zero-crossing signal to the controller 20 based on the zero-crossing point of the AC power supply 200, wherein the AC power supply 200 is a sine wave. In a specific embodiment, the AC power supply 200 is a mains power supply, the first end of the AC power supply 200 is a live wire, and the second end is a zero wire. The controller 20 is configured to determine the zero-crossing point of the AC power supply 200 based on the zero-crossing signal, and output a pulse based on each zero-crossing point, wherein the start time of each pulse is earlier than the corresponding zero-crossing point. The controller 20 can adopt a microcontroller unit (MCU) or a digital signal processing (DSP) controller, etc. The switch branch 30 is configured to be turned on in response to the pulse to establish a connection between the first power supply and the control end of the thyristor DW1. The thyristor DW1 is configured to be turned on when it is connected to the first power source V1 to establish a connection between the second end of the energy storage branch 40 and the second end of the AC power source 200, and is configured to be turned off when the AC power source 200 is at a zero crossing point. The energy storage branch 40 is configured to be charged by the AC power source 200 to store energy when the thyristor DW1 is turned on.

[0046] Please refer to Figure 2 , Figure 2 The schematic diagram of the AC power supply and pulse in one embodiment is exemplarily shown, wherein the horizontal axis is time. Curve S1 is the pulse output by the controller 20 ; curve S2 is the AC power supply 200 .

[0047] Specifically, when the household appliance including the startup control circuit 100 is started, the zero-crossing detection branch 10 can output a zero-crossing signal to the controller 20 in real time based on the zero-crossing point of the AC power source 200. Then, the controller 20 can determine the zero-crossing point of the AC power source 200. For example Figure 2 The T2 moment and the T4 moment shown are both the moments when the AC power supply 200 crosses the zero point. At the same time, the controller 20 outputs a pulse to the switch branch 30 at the moment before each zero-crossing moment to turn on the switch branch 30. The first power supply V1 is input to the control end of the thyristor DW1 through the switch branch 30 to turn on the thyristor DW1. The AC power supply 200, the energy storage branch 40 and the thyristor DW1 form a path, and the AC power supply 200 charges the energy storage branch 40. Until the AC power supply 200 is at the moment of crossing the zero point, the thyristor DW1 is turned off, and the AC power supply 200 stops charging the energy storage branch 40. Then, when waiting for the next pulse to arrive, the switch branch 30 is turned on again, and the same process as above is continued. Among them, at the end of each pulse, the switch branch 30 is disconnected.

[0048] In the above process, by configuring the start time of the pulse to be close to the corresponding zero-crossing time, so that the time when the thyristor DW1 is turned on is close to the corresponding zero-crossing time, the AC power supply 200 can be placed at a lower voltage position when the thyristor DW1 is turned on. For example, the T1 moment is the start time of the pulse, and is also the time when the thyristor DW1 is turned on, and T2 is the time when the thyristor DW1 is turned on, which corresponds to the zero-crossing time when the thyristor DW1 is turned on. By configuring the T1 moment to be close to the T2 moment, the AC power supply 200 can be placed at a lower voltage position when the thyristor DW1 is turned on. Compared with the scheme using relays in the related art, in the embodiment of the present application, since the AC power supply 200 is placed at a lower voltage position when the thyristor DW1 is turned on, the surge current generated when the AC power supply 200 charges the energy storage branch 40 is smaller, resulting in a smaller risk of device damage, thereby improving stability and reliability.

[0049] In some embodiments, the time between the moment when the thyristor DW1 is turned on and the moment when the corresponding zero-crossing point is gradually increased may be adopted to speed up the charging speed of the energy storage branch 40 while generating a smaller surge current. Figure 2 As shown, the time length between the time T4 and the time T3 is configured to be greater than the time length between the time T2 and the time T1, so as to gradually increase the time length between the time when the thyristor DW1 is turned on and the corresponding zero-crossing point.

[0050] In the related art, when a relay solution is adopted, in order to reduce the surge current, a corresponding current limiting element, such as a positive temperature coefficient thermistor, is usually set between the AC power supply and the electrolytic capacitor. The positive temperature coefficient (PTC) thermistor is a resistor element that changes its resistance value according to temperature changes. In a PTC thermistor, as the temperature increases, the resistance value will also increase; and when the temperature drops, the resistance value will decrease. Thus, when an excessive current is generated in the circuit, the PTC thermistor will automatically increase the resistance value to achieve the function of protecting the circuit. However, when the household appliance is operating normally, the PTC thermistor will affect the load or cause additional power consumption. Subsequently, it is necessary to set a corresponding circuit structure, such as a circuit composed of a relay, to short-circuit the PTC thermistor. However, this method will lead to an increase in cost. It can be seen that, compared with the above-mentioned method in the related art, the embodiment of the present application can reduce the current limiting element and the related circuit for short-circuiting the current limiting element, and the cost is lower.

[0051] In one embodiment, if Figure 3 As shown, the startup control circuit 100 further includes a first signal processing branch 50 .

[0052] The first signal processing branch 50 is connected to the switch branch 30 and the control end of the thyristor DW1 respectively. The first signal processing branch 50 is configured to filter the first power supply V1 and limit the current between the switch branch 30 and the control end of the thyristor DW1 to prevent the thyristor DW1 from being damaged due to excessive current or voltage.

[0053] In one embodiment, if Figure 4 As shown, the startup control circuit 100 further includes a second signal processing branch 60 .

[0054] The second signal processing branch 60 is respectively connected to the AC power source 200, the thyristor DW1 and the energy storage branch 40. The second signal processing branch 60 is configured to filter and rectify the AC power source 200 and then input it to the energy storage branch 40 to charge the energy storage branch 40 when the thyristor DW1 is turned on.

[0055] Please refer to Figure 5 , Figure 5 A circuit structure of the startup control circuit 100 provided in an embodiment of the present application. Figure 5 As shown, the zero-crossing detection branch 10 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a first capacitor C1, a second capacitor C2 and a first switch tube Q1.

[0056] Among them, the first resistor R1 and the second resistor R2 are connected in series between the first end of the AC power supply 200 and the ground GND, the connection point between the first resistor R1 and the second resistor R2 is connected to the first end of the first switch tube Q1, the second end of the first switch tube Q1 is connected to the ground GND, the first capacitor C1 is connected in parallel with the first resistor R1, the anode of the first diode D1 is connected to the first end of the first switch tube Q1, and the cathode of the first diode D1 is connected to the ground GND, the third resistor R3 and the fourth resistor R4 are connected in series between the controller 20 and the first power supply V1, the connection point between the third resistor R3 and the fourth resistor R4 is connected to the third end of the first switch tube Q1, and the third resistor R3 and the fourth resistor R4 are connected in series and connected in parallel with the second capacitor C2.

[0057] Specifically, the first resistor R1 and the second resistor R2 are used for voltage division. The first capacitor C1 and the second capacitor C2 are used for filtering. The first diode D1 is used to clamp the voltage between the first end and the second end of the first switch tube Q1 to prevent the voltage between the first end and the second end of the first switch tube Q1 from being too high.

[0058] When the voltage of the AC power supply 200 is greater than or equal to the negative value of the conduction voltage drop of the first switch tube Q1, the first switch tube Q1 is disconnected, and the first power supply V1 is input to the controller 20 through the third resistor R3 and the fourth resistor R4; when the AC power supply 200 is less than the negative value of the conduction voltage drop of the first switch tube Q1, the first switch tube Q1 is turned on, and the controller 20 is grounded to GND with the first switch tube Q1 through the fourth resistor R4. It can be seen that the controller 20 will alternately receive the level signal corresponding to the first power supply V1 (recorded as the first level signal) and the level signal corresponding to the ground GND (recorded as the second level signal), and the first level signal and the second level signal constitute a zero-crossing signal. The controller 20 determines the moment when the first level signal in the zero-crossing signal switches to the second level signal or the moment when the second level signal switches to the first level signal as the moment of the zero-crossing point. It can be understood that when the first power supply V1 is a negative voltage, such as -5V, the first level signal is a low level signal and the second level signal is a high level signal.

[0059] In this embodiment, the first switch tube Q1 is a PNP transistor as an example. The base of the PNP transistor is the first end of the first switch tube Q1, the emitter of the PNP transistor is the second end of the first switch tube Q1, and the collector of the PNP transistor is the third end of the first switch tube Q1.

[0060] In addition, the first switch tube Q1 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0061] In this embodiment, the switch branch 30 includes a fifth resistor R5, a sixth resistor R6 and a second switch tube Q2.

[0062] Among them, the fifth resistor R5 and the sixth resistor R6 are connected in series between the controller 20 and the first power supply V1, the connection point between the fifth resistor R5 and the sixth resistor R6 is connected to the first end of the second switch tube Q2, the second end of the second switch tube Q2 is connected to the first power supply V1, and the third end of the second switch tube Q2 is connected to the control end of the thyristor DW1.

[0063] Specifically, the fifth resistor R5 and the sixth resistor R6 are used for voltage division, and the fifth resistor R5 is also used for current limiting.

[0064] When the controller 20 outputs a pulse, at the beginning of the pulse, the second switch tube Q2 is turned on, and the first power supply V1 acts on the control end of the thyristor DW1 through the second switch tube Q2 and the seventh resistor R7 to turn on the thyristor DW1; at the end of the pulse, the second switch tube Q2 is turned off.

[0065] In this embodiment, the second switch tube Q2 is an NPN transistor as an example. The base of the NPN transistor is the first end of the second switch tube Q2, the emitter of the NPN transistor is the second end of the second switch tube Q2, and the collector of the NPN transistor is the third end of the second switch tube Q2.

[0066] In addition, the second switch tube Q2 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0067] In this embodiment, the energy storage branch 40 includes a third capacitor C3.

[0068] The third capacitor C3 is connected between the first end and the second end of the AC power supply 200, specifically, the first end of the third capacitor C3 is connected to the first end of the AC power supply 200 through the second signal processing branch 60, and outputs the second power supply V2, and the second end of the third capacitor C3 is connected to the second end of the AC power supply 200 through the second signal processing branch 60 and the thyristor DW1. The third capacitor C3 is an electrolytic capacitor.

[0069] In this embodiment, the first signal processing branch 50 includes a seventh resistor R7, an eighth resistor R8 and a fourth capacitor C4.

[0070] The seventh resistor R7 is connected between the switch branch 30 and the control terminal of the thyristor DW1 , the fourth capacitor C4 is connected between the second terminal of the AC power source 200 and the control terminal of the thyristor DW1 , and the eighth resistor R8 is connected in parallel with the fourth capacitor C4 .

[0071] Specifically, the seventh resistor R7 is used for current limiting, and the eighth resistor R8 and the fourth capacitor C4 are used for filtering.

[0072] In this embodiment, the second signal processing branch 60 includes an inductor L1 and a rectifier bridge U1 .

[0073] Among them, the first end of the inductor L1 is connected to the first end of the AC power supply 200, the second end of the inductor L1 is connected to the first end of the rectifier bridge U1, the second end of the rectifier bridge U1 is connected to the first end of the energy storage branch 40, the third end of the rectifier bridge U1 is connected to the ground GND, the fourth end of the rectifier bridge U1 is connected to the third end of the inductor L1, the fourth end of the inductor L1 is connected to the second end of the non-control end of the thyristor DW1, and the first end of the non-control end of the thyristor DW1 is connected to the second end of the AC power supply 200.

[0074] Specifically, the inductor L1 is a common mode inductor used for filtering. The rectifier bridge U1 is used to achieve full-wave rectification.

[0075] The following Figure 5 The principle of the circuit structure shown is explained again.

[0076] When the household appliance including the startup control circuit 100 is started, the zero-crossing detection branch 10 can output a zero-crossing signal to the controller 20 based on the zero-crossing point of the AC power supply 200 in real time. Then, the controller 20 can determine the zero-crossing point of the AC power supply 200. At the same time, the controller 20 outputs a pulse to the second switch tube Q2 at the moment before each zero-crossing moment to turn on the second switch tube Q2. The first power supply V1 is input to the control end of the thyristor DW1 through the second switch tube Q2 and the seventh resistor R7 to turn on the thyristor DW1. The AC power supply 200 forms a path with the inductor L1, the rectifier bridge U1, the third capacitor C3 and the thyristor DW1, and the AC power supply 200 charges the third capacitor C3. Until the AC power supply 200 is at the moment of the zero-crossing point, the thyristor DW1 is turned off, and the AC power supply 200 stops charging the third capacitor C3. Then, the second switch tube Q2 is turned on again when the next pulse arrives, and the same process as above is continued.

[0077] In the above process, by configuring the start time of the pulse to be close to the corresponding zero-crossing time, so that the time when the thyristor DW1 is turned on is close to the corresponding zero-crossing time, the AC power supply 200 can be at a lower voltage position when the thyristor DW1 is turned on. Compared with the solution using relays in the related art, in the embodiment of the present application, since the AC power supply 200 is at a lower voltage position when the thyristor DW1 is turned on, the surge current generated when the AC power supply 200 charges the third capacitor C3 is smaller, resulting in a smaller risk of device damage, thereby improving stability and reliability.

[0078] In some embodiments, the time between the moment when the thyristor DW1 is turned on and the corresponding zero-crossing point may be gradually increased to speed up the charging of the third capacitor C3 while generating a smaller surge current.

[0079] In addition, compared with the solution in the related art that requires the provision of a current limiting element and a related circuit for short-circuiting the current limiting element, the embodiments of the present application can reduce the above-mentioned current limiting element and the related circuit for short-circuiting the current limiting element, and the cost is lower.

[0080] In one embodiment, if Figure 6 As shown, the startup control circuit 100 further includes a first interface J1 and a second interface J2.

[0081] Among them, the first end of the first interface J1 is connected to the first end of the AC power supply 200, the second end of the first interface J1 is connected to the second end of the AC power supply 200 through the thyristor DW1, the first end of the second interface J2 is connected to the first end of the second signal processing branch 60, and the second end of the second interface J2 is connected to the second end of the second signal processing branch 60.

[0082] The first end of the first interface J1 is used to connect to the first end of the second interface J2, and the second end of the first interface J1 is used to connect to the second end of the second interface J2.

[0083] The embodiment of the present application further provides a household appliance, which includes the start-up control circuit 100 in any embodiment of the present application.

[0084] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0085] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A startup control circuit, characterized in that: include: Zero-crossing detection branch, controller, switch branch, thyristor and energy storage branch; The zero-crossing detection branch is connected to the AC power supply and is configured to output a zero-crossing signal to the controller based on a zero-crossing point of the AC power supply, wherein the AC power supply is a sine wave; The controller is connected to the zero-crossing detection branch and is configured to determine the zero-crossing point of the AC power supply based on the zero-crossing signal, and output a pulse based on each zero-crossing point, wherein the start time of each pulse is earlier than the time of the corresponding zero-crossing point; The switch branch is connected to the controller and connected between the first power source and the control terminal of the thyristor, and is configured to be turned on in response to the pulse to establish a connection between the first power source and the control terminal of the thyristor; The thyristor is connected between the second end of the energy storage branch and the second end of the AC power supply, is configured to be turned on when it is connected to the first power supply to establish a connection between the second end of the energy storage branch and the second end of the AC power supply, and is configured to be turned off when the AC power supply is at a zero-crossing point, wherein the first end of the energy storage branch is connected to the first end of the AC power supply; The energy storage branch is configured to be charged by the AC power source to store energy when the thyristor is turned on.

2. The startup control circuit according to claim 1, characterized in that: The startup control circuit also includes: The first signal processing branch is connected to the switch branch and the control end of the thyristor respectively, and is configured to filter the first power supply and limit the current between the switch branch and the control end of the thyristor.

3. The startup control circuit according to claim 1 or 2, characterized in that: The startup control circuit also includes: The second signal processing branch is connected to the AC power supply, the thyristor and the energy storage branch respectively, and is configured to filter and rectify the AC power supply and then input it into the energy storage branch to charge the energy storage branch when the thyristor is turned on.

4. The startup control circuit according to claim 1, characterized in that: The zero-crossing detection branch includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a first capacitor, a second capacitor and a first switch tube; The first resistor and the second resistor are connected in series between the first end of the AC power supply and the ground, the connection point between the first resistor and the second resistor is connected to the first end of the first switch tube, the second end of the first switch tube is connected to the ground, the first capacitor is connected in parallel with the first resistor, the anode of the first diode is connected to the first end of the first switch tube, and the cathode of the first diode is connected to the ground, the third resistor and the fourth resistor are connected in series between the controller and the first power supply, the connection point between the third resistor and the fourth resistor is connected to the third end of the first switch tube, and the third resistor and the fourth resistor are connected in series and then connected in parallel with the second capacitor.

5. The startup control circuit according to claim 1, characterized in that: The switch branch includes a fifth resistor, a sixth resistor and a second switch tube; The fifth resistor and the sixth resistor are connected in series between the controller and the first power supply, the connection point between the fifth resistor and the sixth resistor is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the first power supply, and the third end of the second switch tube is connected to the control end of the thyristor.

6. The startup control circuit according to claim 1, characterized in that: The energy storage branch includes a third capacitor; The third capacitor is connected between the first terminal and the second terminal of the AC power source.

7. The startup control circuit according to claim 2, characterized in that: The first signal processing branch includes a seventh resistor, an eighth resistor and a fourth capacitor; The seventh resistor is connected between the switch branch and the control end of the thyristor, the fourth capacitor is connected between the second end of the AC power supply and the control end of the thyristor, and the eighth resistor is connected in parallel with the fourth capacitor.

8. The startup control circuit according to claim 3, characterized in that: The second signal processing branch includes an inductor and a rectifier bridge; The first end of the inductor is connected to the first end of the AC power supply, the second end of the inductor is connected to the first end of the rectifier bridge, the second end of the rectifier bridge is connected to the first end of the energy storage branch, the third end of the rectifier bridge is connected to the ground, the fourth end of the rectifier bridge is connected to the third end of the inductor, the fourth end of the inductor is connected to the second end of the thyristor non-control end, and the first end of the thyristor non-control end is connected to the second end of the AC power supply.

9. The startup control circuit according to claim 3, characterized in that: The startup control circuit also includes a first interface and a second interface; The first end of the first interface is connected to the first end of the AC power supply, the second end of the first interface is connected to the second end of the AC power supply through the thyristor, the first end of the second interface is connected to the first end of the second signal processing branch, and the second end of the second interface is connected to the second end of the second signal processing branch; The first end of the first interface is used to connect to the first end of the second interface, and the second end of the first interface is used to connect to the second end of the second interface.

10. A household appliance, characterized in that: Comprising a startup control circuit as described in any one of claims 1-9.

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