Load switch power supply control circuit of electric equipment and electric equipment

Abstract

The utility model discloses a load switch power supply control circuit of electric equipment and the electric equipment, the load switch power supply control circuit comprises a switch circuit, one end of a switch path of the switch circuit is connected with a driving power supply, and the other end of the switch path is connected with a power supply end of a load switch; the anode of the first diode is connected with the direct-current power supply through a first pull-up resistor; the anode of the second diode is connected with the direct-current power supply through a second pull-up resistor; the cathode of the second diode is connected with the cathode of the first diode, and a connection node is connected with the control end of the switching circuit; one end of the first door switch is connected with the anode of the first diode, the other end of the first door switch is grounded, and the first door switch is disconnected when a door body of the electric equipment is opened; one end of the second door switch is connected with the anode of the second diode, the other end of the second door switch is grounded, and the second door switch is disconnected when the door body of the electric equipment is opened. According to the load switch power supply control circuit of the utility model, the strong current load power-off function is realized when the door body is opened, and the real-time performance is high; by arranging the two door switches, the accuracy of door opening and closing detection is improved; the switching circuit is used for controlling whether the driving power supply supplies power to the load switch or not so as to control the on-off of a strong-current load power supply line, a total switching relay does not need to be additionally designed, the cost is low, the occupied space is small, PCB layout and wiring are convenient, and the technical problems of low door opening and closing detection accuracy and high cost in the prior art are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of circuits, and specifically relates to a load switch power supply control circuit for an electrical device and an electrical device. Background Art

[0002] In the design of some household appliances, a function needs to be realized, that is, when the door of a household appliance is opened, the power supply of some high-power loads needs to be immediately cut off to protect the safety of users and avoid damage to household appliances. To realize this function, corresponding designs need to be carried out on the household appliance control board.

[0003] The existing solution is to design a door switch detection circuit and an AC power total cut-off circuit. First, the microcontroller detects whether the door switch is in the closed state or the open state through the detection circuit. Then, when it is detected that the door switch is open, the microcontroller realizes the total cut-off of the AC power through the total cut-off relay, that is, when the door switch is open, the total cut-off relay cuts off the total AC power supply of the household appliance product. After the total AC power supply is cut off, all high-power loads are powered off.

[0004] This solution has the following disadvantages: First, there is only one-way door switch detection circuit in the existing circuit. Due to the mechanical structure error of the door switch, the switch state detection may be incorrect. Second, there is only one detection and control circuit in the existing circuit. Once a fault occurs in this circuit, the power-off function will fail. Finally, an additional total cut-off relay needs to be designed in the existing circuit to cut off the total AC power supply when the door switch is open, and this relay often requires a relay with high current tolerance, which is costly, occupies a large space, and is not conducive to the PCB layout and wiring and the overall machine structure design. Summary of the Invention

[0005] The utility model provides a load switch power supply control circuit for an electrical device, which solves the technical problems of low accuracy of door opening and closing detection and high cost in the prior art.

[0006] To achieve the above technical purpose, the utility model is realized by adopting the following technical solutions:

[0007] The load switch power supply control circuit for an electrical device includes:

[0008] A switch circuit, one end of its switch path is connected to a driving power supply, and the other end of its switch path is connected to the power supply terminal of a load switch;

[0009] A first diode, its anode is connected to a DC power supply through a first pull-up resistor;

[0010] A second diode, its anode is connected to the DC power supply through a second pull-up resistor; the cathode of the second diode is connected to the cathode of the first diode, and the connection node is connected to the control end of the switch circuit;

[0011] The first door switch, one end of which is connected to the anode of the first diode, the other end of which is grounded, and which is disconnected when the door of the electrical device is opened;

[0012] The second door switch, one end of which is connected to the anode of the second diode, the other end of which is grounded, and which is disconnected when the door of the electrical device is opened.

[0013] In some embodiments of the present application, the switch circuit includes a first switch tube, a second switch tube, and a third switch tube;

[0014] The control end of the first switch tube is connected to the connection node of the first diode and the second diode through a first current-limiting resistor;

[0015] One end of the switching path of the first switch tube is connected to the driving power supply through a second current-limiting resistor, and the other end of the switching path of the first switch tube is grounded;

[0016] One end of the switching path of the first switch tube is connected to the control end of the second switch tube, one end of the switching path of the second switch tube is connected to the driving power supply through a voltage-dividing circuit, and the other end of the switching path of the second switch tube is grounded;

[0017] The voltage-dividing node of the voltage-dividing circuit is connected to the control end of the third switch tube; one end of the switching path of the third switch tube is connected to the driving power supply, and the other end of the switching path of the third switch tube is connected to the power supply end of the load switch.

[0018] In some embodiments of the present application, the voltage-dividing circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor. One end of the first voltage-dividing resistor is connected to one end of the switching path of the second switch tube, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor, and the other end of the second voltage-dividing resistor is connected to the driving power supply;

[0019] The connection node of the first voltage-dividing resistor and the second voltage-dividing resistor is connected to the control end of the third switch tube.

[0020] In some embodiments of the present application, the load switch power supply control circuit further includes a control unit;

[0021] The first detection end of the control unit is connected to one end of the first door switch through a third current-limiting resistor;

[0022] The second detection end of the control unit is connected to one end of the second door switch through a fourth current-limiting resistor;

[0023] The output end of the control unit is connected to the control end of the switch circuit through a fifth current-limiting resistor.

[0024] In some embodiments of the present application, the first detection end of the control unit is grounded through a first filter capacitor;

[0025] The second detection end of the control unit is grounded through a second filter capacitor.

[0026] In some embodiments of the present application, the control end of the first switching transistor is grounded through a third filter capacitor.

[0027] In some embodiments of the present application, the other end of the switching path of the third switching transistor is grounded through a fourth filter capacitor.

[0028] In some embodiments of the present application, the first switching transistor is an NPN triode, the second switching transistor is an NPN triode, and the third switching transistor is a PMOS transistor.

[0029] Based on the design of the above load switch power supply control circuit, the present utility model proposes an electrical device, including:

[0030] A box body;

[0031] A door body, which is arranged on the box body;

[0032] A high-power load, which is arranged in the box body;

[0033] A load switch, which is connected in series in the power supply loop of the high-power load;

[0034] For the load switch power supply control circuit described above, the other end of the switching path of its switching circuit is connected to the power supply end of the load switch.

[0035] In some embodiments of the present application, the load switch is a relay;

[0036] The power supply end of the coil of the relay is connected to the other end of the switching path of the switching circuit of the load switch power supply control circuit;

[0037] The normally open contact of the relay is connected in series in the power supply loop of the high-power load.

[0038] Compared with the prior art, the advantages and positive effects of the present utility model are as follows: For the load switch power supply control circuit and the electrical equipment of the present utility model, one end of the switch path of the designed switch circuit is connected to the driving power supply, and the other end is connected to the power supply terminal of the load switch; the anode of the first diode is connected to the DC power supply through the first pull-up resistor; the anode of the second diode is connected to the DC power supply through the second pull-up resistor; the cathode of the second diode is connected to the cathode of the first diode, and the connection node is connected to the control terminal of the switch circuit; one end of the first gate switch is connected to the anode of the first diode, and the other end is grounded; one end of the second gate switch is connected to the anode of the second diode, and the other end is grounded; when the door body is opened, the first gate switch is disconnected, the second gate switch is disconnected, the switch path of the switch circuit is disconnected, the driving power supply cannot supply power to the load switch, the load switch is powered off, so that the power supply circuit of the high-power load is disconnected, and thus the high-power load is powered off. Therefore, for the load switch power supply control circuit of the present utility model, when the first gate switch or the second gate switch is disconnected, the switch path of the switch circuit is disconnected, that is, the load switch is powered off, and further the high-power load is powered off, realizing the function of powering off the high-power load when the door body is opened, and having high real-time performance; by setting two gate switches, the accuracy rate of door opening and closing detection is improved; the switch circuit is used to control whether the driving power supply supplies power to the load switch, and further control the on-off of the high-power load power supply line, without the need to additionally design a main cut-off relay, with low cost, small occupied space, convenient for PCB layout and wiring, and solving the technical problems of low accuracy rate of door opening and closing detection and high cost in the prior art.

[0039] After reading the detailed description of the embodiments of the present utility model in conjunction with the drawings, other features and advantages of the present utility model will become clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 It is the circuit schematic diagram of an embodiment of the load switch power supply control circuit proposed by the present utility model;

[0042] Figure 2 It is the circuit schematic diagram of another embodiment of the load switch power supply control circuit proposed by the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the following will further elaborate on the present utility model in detail in conjunction with the drawings and embodiments.

[0044] It should be noted that in the description of the present utility model, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0045] In addition, it should also be noted that in the description of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0046] Embodiment 1

[0047] The power supply control circuit for the load switch of the electrical equipment in this embodiment includes a switch circuit, a first gate switch K1, a second gate switch K2, a first diode D23, a second diode D24, etc., as shown in Figure 1 shown.

[0048] The switch circuit, one end of its switch path is connected to a driving power supply (such as a 12V driving power supply), and the other end of its switch path is connected to the power supply terminal of the load switch. When the switch path of the switch circuit is turned on, the power supply provided by the driving power supply is transmitted to the power supply terminal of the load switch through the switch path of the switch circuit to supply power to the load switch. The load switch is connected in series in the power supply circuit of the high-power load. When the load switch is powered on, the power supply circuit of the high-power load is turned on. When the load switch is powered off, the power supply circuit of the high-power load is turned off.

[0049] The first diode D23, its anode is connected to a DC power supply (such as a +5V DC power supply) through a first pull-up resistor R124.

[0050] The second diode D24, its anode is connected to a DC power supply (such as a +5V DC power supply) through a second pull-up resistor R153. The cathode of the second diode D24 is connected to the cathode of the first diode D23, and the connection node is connected to the control terminal of the switch circuit.

[0051] The first door switch K1, one end of which is connected to the anode of the first diode D23 and the other end is grounded. The first door switch K1 is disconnected when the door of the electrical equipment is opened; the first door switch K1 is closed when the door of the electrical equipment is closed.

[0052] The second door switch K2, one end of which is connected to the anode of the second diode D24 and the other end is grounded. The second door switch K2 is disconnected when the door of the electrical equipment is opened; the second door switch K2 is closed when the door of the electrical equipment is closed.

[0053] The first door switch K1 and the second door switch K2 are disconnected or closed according to the opening and closing of the door. The first diode D23 and the second diode D24 are used to prevent current backflow. When the control end of the switch circuit is at a low level, the switch path of the switch circuit is turned on. When the control end of the switch circuit is at a high level, the switch path of the switch circuit is disconnected.

[0054] When the door is closed, the first door switch K1 is closed, the second door switch K2 is closed, the anode of the first diode D23 is pulled down to a low level, the anode of the second diode D24 is pulled down to a low level, the cathodes of the first diode D23 and the second diode D24 are both at a low level. Therefore, the control end of the switch circuit is at a low level, the switch path of the switch circuit is turned on, the power supply provided by the driving power supply passes through the switch path of the switch circuit to supply power to the load switch, the load switch is powered on, and the power supply circuit of the high-power load is turned on, and the high-power load is powered on.

[0055] When the door is opened, the first door switch K1 is disconnected, the second door switch K2 is disconnected, the power supply provided by the DC power supply is transmitted to the control end of the switch circuit through the first pull-up resistor R124 and the first diode D23; the power supply provided by the DC power supply is transmitted to the control end of the switch circuit through the second pull-up resistor R153 and the second diode D24. That is, the control end of the switch circuit is at a high level, the switch path of the switch circuit is disconnected, the driving power supply cannot supply power to the load switch, the load switch is powered off, the power supply circuit of the high-power load is disconnected, and the high-power load is powered off.

[0056] Suppose one of the door switches fails. For example, the first door switch K1 is closed and the second door switch K2 is disconnected. Then the anode of the first diode D23 is pulled down to a low level, and the power supply provided by the DC power supply is transmitted to the control end of the switch circuit through the second pull-up resistor R153 and the second diode D24. Therefore, the control end of the switch circuit is at a high level, the switch path of the switch circuit is disconnected, the driving power supply cannot supply power to the load switch, the load switch is powered off, the power supply circuit of the high-power load is disconnected, and the high-power load is powered off.

[0057] Therefore, only when both the first gate switch K1 and the second gate switch K2 are closed, the switch path of the switch circuit is turned on, and the drive power supply can supply power to the load switch. When the first gate switch K1 or the second gate switch K2 is open, the switch circuit is turned off, and the drive power supply cannot supply power to the load switch.

[0058] For the load switch power supply control circuit of the electrical equipment in this embodiment, one end of the switch path of the switch circuit is connected to the drive power supply, and the other end is connected to the power supply terminal of the load switch; the anode of the first diode D23 is connected to the DC power supply through the first pull-up resistor R124; the anode of the second diode D24 is connected to the DC power supply through the second pull-up resistor R153; the cathode of the second diode D24 is connected to the cathode of the first diode D23, and the connection node is connected to the control terminal of the switch circuit; one end of the first gate switch K1 is connected to the anode of the first diode D23, and the other end is grounded; one end of the second gate switch K2 is connected to the anode of the second diode D24, and the other end is grounded; when the door body is opened, the first gate switch K1 is opened, the second gate switch K2 is opened, the switch path of the switch circuit is opened, the drive power supply cannot supply power to the load switch, the load switch is powered off, so that the power supply circuit of the strong electrical load is opened, and thus the strong electrical load is powered off. Therefore, for the load switch power supply control circuit of this embodiment, when the first gate switch K1 or the second gate switch K2 is open, the switch path of the switch circuit is opened, that is, the load switch is powered off, and then the strong electrical load is powered off, realizing the function of powering off the strong electrical load when the door body is opened, and having high real-time performance; by setting two gate switches, the accuracy of door opening and closing detection is improved; the switch circuit is used to control whether the drive power supply supplies power to the load switch, and then control the on and off of the power supply line of the strong electrical load, without the need to additionally design a main cut-off relay (the main cut-off relay is used to cut off the total AC power supply of the electrical equipment, and after the total AC power supply is cut off, the strong electrical load is powered off), with low cost, small occupied space, convenient for PCB layout and wiring, and solving the technical problems of low accuracy of door opening and closing detection and high cost in the prior art.

[0059] In some embodiments of the present application, the switch circuit includes a first switching transistor N11, a second switching transistor N10, and a third switching transistor Q2, as shown in Figure 2 shown. The first switching transistor N11 and the second switching transistor N10 are high-conduction-voltage-drop switching transistors, and the third switching transistor Q2 is a low-conduction-voltage-drop switching transistor.

[0060] The control terminal of the first switching transistor N11 is connected to the connection node of the first diode D23 and the second diode D24 through the first current-limiting resistor R134.

[0061] One end of the switch path of the first switching transistor N11 is connected to the drive power supply through the second current-limiting resistor R129, and the other end of the switch path of the first switching transistor N11 is grounded.

[0062] One end of the switching path of the first switching transistor N11 is connected to the control end of the second switching transistor N10. One end of the switching path of the second switching transistor N10 is connected to the driving power supply through a voltage dividing circuit, and the other end of the switching path of the second switching transistor N10 is grounded.

[0063] The voltage dividing node of the voltage dividing circuit is connected to the control end of the third switching transistor Q2; one end of the switching path of the third switching transistor Q2 is connected to the driving power supply, and the other end of the switching path of the third switching transistor Q2 is connected to the power supply end of the load switch.

[0064] When both the first gate switch K1 and the second gate switch K2 are closed, the control end of the first switching transistor N11 is at a low level, the switching path of the first switching transistor N11 is turned off, and under the pull-up action of the driving power supply, the control end of the second switching transistor N10 is at a high level, the switching path of the second switching transistor N10 is turned on, the current provided by the driving power supply flows into the ground through the voltage dividing circuit and the switching path of the second switching transistor N10, the switching path of the third switching transistor Q2 is turned on, and the current provided by the driving power supply flows to the power supply end of the load switch through the switching path of the third switching transistor Q2 to supply power to the load switch, and the load switch is powered on.

[0065] When the first gate switch K1 or the second gate switch K2 is disconnected, the control end of the first switching transistor N11 is at a high level, the switching path of the first switching transistor N11 is turned on, the control end of the second switching transistor N10 is pulled down to a low level, the switching path of the second switching transistor N10 is turned off, the switching path of the third switching transistor Q2 is turned off, the driving power supply cannot supply power to the load switch, the load switch is powered off, and the high-power load is powered off.

[0066] By designing the above three switching transistors, the on-off of the power supply line for the driving power supply to supply power to the load switch is controlled, which is convenient to control, has low cost, occupies a small space, and utilizes PCB layout and wiring.

[0067] In some embodiments of the present application, the voltage dividing circuit includes a first voltage dividing resistor R130 and a second voltage dividing resistor R125. One end of the first voltage dividing resistor R130 is connected to one end of the switching path of the second switching transistor N10, the other end of the first voltage dividing resistor R130 is connected to one end of the second voltage dividing resistor R125, and the other end of the second voltage dividing resistor R125 is connected to the driving power supply. The connection node (i.e., the voltage dividing node) of the first voltage dividing resistor R130 and the second voltage dividing resistor R125 is connected to the control end of the third switching transistor Q2.

[0068] When the second switching transistor N10 is turned on, the voltage division of the first voltage dividing resistor R130 and the second voltage dividing resistor R125 causes the third switching transistor Q2 to be turned on; when the second switching transistor N10 is turned off, the third switching transistor Q2 is turned off.

[0069] The voltage dividing circuit with the above structure can control the on / off of the third switching transistor Q2 according to the on / off of the second switching transistor N10, with a simple structure and easy to implement.

[0070] In some other embodiments of the present application, in order to further improve the accuracy of the on / off control of the switching circuit, the load switch power supply control circuit further includes a control unit; the first detection end of the control unit is connected to one end of the first gate switch K1 through a third current limiting resistor R127; the second detection end of the control unit is connected to one end of the second gate switch K2 through a fourth current limiting resistor R147; the output end of the control unit is connected to the control end of the switching circuit (specifically, the control end of the first switching transistor N11) through a fifth current limiting resistor R170.

[0071] When the first gate switch K1 is closed, one end of the first gate switch K1 is at a low level. Therefore, the first detection end of the control unit receives a low level. When the second gate switch K2 is closed, one end of the second gate switch K2 is at a low level. Therefore, the second detection end of the control unit receives a low level.

[0072] When the first gate switch K1 is opened, one end of the first gate switch K1 is pulled up to a high level. Therefore, the first detection end of the control unit receives a high level. When the second gate switch K2 is opened, one end of the second gate switch K2 is pulled up to a high level. Therefore, the second detection end of the control unit receives a high level.

[0073] When both detection ends of the control unit receive low levels, the output end of the control circuit outputs a control signal to the control end of the switching circuit to control the switching path of the switching circuit to conduct. For example, the control circuit outputs a low level signal to the control end of the first switching transistor N11, the switching path of the first switching transistor N11 is turned off, the switching path of the second switching transistor N10 is turned on, the switching path of the third switching transistor Q2 is turned on, and the driving power supply supplies power to the load switch through the switching path of the third switching transistor Q2.

[0074] When the first detection end or the second detection end of the control unit receives a high level, the output end of the control circuit outputs a control signal to the control end of the switching circuit to control the switching path of the switching circuit to turn off. For example, the control circuit outputs a high level signal to the control end of the first switching transistor N11, the switching path of the first switching transistor N11 is turned on, the switching path of the second switching transistor N10 is turned off, the switching path of the third switching transistor Q2 is turned off, and the driving power supply cannot supply power to the load switch.

[0075] For example, the control unit includes an MCU and an OR gate, the first detection end is connected to the first input end of the OR gate, the second detection end is connected to the second input end of the OR gate, and the output end of the OR gate is connected to the MCU.

[0076] When the MCU receives the low level output by the OR gate, the control circuit outputs a low level signal to the control terminal of the first switching transistor N11, controlling the first switching transistor N11 to turn off. Further, the second switching transistor N10 turns on, and the third switching transistor Q2 turns on.

[0077] When the MCU receives the high level output by the OR gate, the control circuit outputs a high level signal to the control terminal of the first switching transistor N11, controlling the first switching transistor N11 to turn on, the second switching transistor N10 to turn off, and the third switching transistor Q2 to turn off.

[0078] In some embodiments of the present application, in order to improve the accuracy of the signal received by the control unit, the first detection terminal of the control unit is grounded through the first filter capacitor C58. The first filter capacitor C58 is used to filter out the clutter and avoid interfering with the first detection terminal. The second detection terminal of the control unit is grounded through the second filter capacitor C64. The second filter capacitor C64 is used to filter out the clutter and avoid interfering with the second detection terminal.

[0079] In some embodiments of the present application, in order to ensure the stability of the on-off state of the first switching transistor N11, the control terminal of the first switching transistor N11 is grounded through the third filter capacitor C60. The third filter capacitor C60 is used to filter out the clutter and avoid interfering with the control terminal of the first switching transistor.

[0080] In some embodiments of the present application, the other end of the switching path of the third switching transistor Q2 is grounded through the fourth filter capacitor C56. The fourth filter capacitor C56 is used to filter out the clutter and ensure the stability of the power supply output to the load switch.

[0081] In some embodiments of the present application, the first switching transistor N11 is an NPN triode, the second switching transistor N10 is an NPN triode, and the third switching transistor Q2 is a PMOS transistor.

[0082] By selecting the above NPN triode and PMOS transistor, the performance is stable, the cost is low, and it is convenient to control the on-off.

[0083] In this embodiment, the first door switch and the second door switch are door magnetic switches or mechanical switches, etc., and are not limited to the above examples.

[0084] The load switch power supply control circuit of this embodiment is applicable to the control of the load switch by the door switch of the household appliance product. By using two door switches, it synchronously realizes the dual control mode of directly controlling the cutting-off of the load switch drive power supply by the hardware circuit and the control unit real-time detecting the door switch state and then controlling the cutting-off of the load switch drive power supply, and can realize more accurate and reliable load switch control. At the same time, the scheme of using three switching transistors to control the load switch drive power supply of each path can save the additional total cut-off relay, save cost and space, and is beneficial to the PCB layout and wiring design.

[0085] The load switch power supply control circuit of this embodiment realizes a solution for controlling a high-power load switch with a door switch, which has high detection accuracy, low functional failure rate, low cost, small occupied space, and is convenient for PCB layout and wiring design and the overall machine structure design.

[0086] The load switch power supply control circuit of this embodiment is designed with two door switches. By controlling the drive power supply of the load switch, the on / off of the high-power load can be controlled, which can avoid the situation of incorrect switch state detection caused by the mechanical structure error of the door switch and also avoid the functional failure caused by the failure of a single door switch. It is designed with two control paths. One is that the control unit controls the on / off of the switch circuit, and the other is that the two door switches control the on / off of the switch circuit, which can avoid the situation of functional failure caused by the failure of a single path. By controlling the on / off of the switch circuit, the power supply of the load switch is controlled, and then the power supply of the high-power load is controlled, which can eliminate the main cut-off relay for controlling the total cut-off of the main AC power supply, save space and cost, and is convenient for PCB layout and wiring design and the overall machine structure design.

[0087] Embodiment 2

[0088] Based on the design of the load switch power supply control circuit proposed in the above Embodiment 1, this Embodiment 2 also proposes an electrical device.

[0089] The electrical device includes a box body, a door body, a high-power load, a load switch, and the above-mentioned load switch power supply control circuit, etc.

[0090] The door body is arranged on the box body and can be opened or closed.

[0091] The high-power load is arranged inside the box body.

[0092] The load switch is connected in series in the power supply circuit of the high-power load. When the load switch is powered on, the power supply circuit of the high-power load is turned on. When the load switch is powered off, the power supply circuit of the high-power load is turned off.

[0093] The load switch power supply control circuit, the other end of the switch path of its switch circuit is connected to the power supply terminal of the load switch. The load switch power supply control circuit is used to control whether the high-power load is powered on or not.

[0094] For the electrical equipment in this embodiment, by designing the load switch power supply control circuit described above, when the door body is opened, the switch path of the switch circuit is disconnected, that is, the load switch is powered off, and then the strong - power load is powered off, realizing the function of power - off of the strong - power load when the door body is opened, and the real - time performance is high; by setting two door switches, the accuracy of door opening and closing detection is improved; using the switch circuit to control whether the drive power supply supplies power to the load switch, and then controlling the on - off of the power supply line of the strong - power load, there is no need to design an additional main cut - off relay (the main cut - off relay is used to cut off the total AC power supply of the electrical equipment, and after the total AC power supply is cut off, the strong - power load is powered off), with low cost, small occupied space, convenient for PCB layout and wiring, solving the technical problems of low accuracy of door opening and closing detection and high cost in the prior art.

[0095] By designing a load - switch power - supply control circuit in the electrical equipment, the operation reliability and safety of the electrical equipment are improved, and the competitiveness of the electrical equipment is enhanced.

[0096] In some embodiments of the present application, the load switch is a relay; the power - supply terminal of the coil of the relay is connected to the other end of the switch path of the switch circuit of the load - switch power - supply control circuit; the normally - open contact of the relay is connected in series in the power - supply circuit of the strong - power load.

[0097] When the switch path of the switch circuit is conducting, the drive power supply supplies power to the coil of the relay through the switch path of the switch circuit, the coil is powered on, the normally - open contact closes, and the power - supply circuit of the strong - power load is conducting.

[0098] When the switch path of the switch circuit is turned off, the coil of the relay loses power, the normally - open contact opens, and the power - supply circuit of the strong - power load is disconnected.

[0099] Using a relay as the load switch can conveniently control the on - off of the power - supply circuit of the strong - power load.

[0100] In some other embodiments of the present application, the load switch is a thyristor; the control electrode G of the thyristor is connected to the other end of the switch path of the switch circuit of the load - switch power - supply control circuit; the anode and cathode of the thyristor are connected in series in the power - supply circuit of the strong - power load.

[0101] When the switch path of the switch circuit is conducting, the drive power supply supplies power to the control electrode G of the thyristor through the switch path of the switch circuit, the anode and cathode of the thyristor conduct, and the power - supply circuit of the strong - power load is conducting.

[0102] When the switch path of the switch circuit is turned off, the control electrode G of the thyristor loses power, the anode and cathode of the thyristor are disconnected, and the power - supply circuit of the strong - power load is disconnected.

[0103] Using a thyristor as the load switch can conveniently control the on - off of the power - supply circuit of the strong - power load.

[0104] Therefore, the load switch can be a power switch device such as a relay or a thyristor, and the driving power supply supplies power to the coil of the relay or the control electrode of the thyristor through the switching path of the switching circuit.

[0105] The electrical equipment in this embodiment is a dishwasher, a refrigerator, a washing machine, a dryer, etc.

[0106] The high-power loads of the dishwasher are heating tubes, AC washing pumps, AC drainage pumps, PTC heaters, etc.

[0107] The high-power load of the refrigerator is a heater, etc.

[0108] The high-power loads of the washing machine are heating tubes, etc. The high-power loads of the dryer are heating tubes, etc.

[0109] When the door of the electrical equipment is opened, the switching path of the switching circuit is disconnected, the driving power supply cannot supply power to the load switch, the load switch is disconnected, and further the power supply circuit of the high-power load is disconnected, and the high-power load is powered off to ensure the safety of the user.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A load switch power supply control circuit for electrical equipment, characterized in that: include: A switch circuit, one end of the switch path of which is connected to a driving power source, and the other end of the switch path of which is connected to a power source end of a load switch; A first diode, an anode of which is connected to a DC power supply via a first pull-up resistor; a second diode, an anode of which is connected to the DC power supply via a second pull-up resistor; a cathode of the second diode is connected to the cathode of the first diode, and a connection node is connected to the control end of the switch circuit; A first door switch, one end of which is connected to the anode of the first diode and the other end of which is grounded, and which is disconnected when the door of the electrical device is opened; The second door switch has one end connected to the anode of the second diode and the other end grounded, and is disconnected when the door of the electrical device is opened.

2. The load switch power supply control circuit according to claim 1, characterized in that: The switch circuit includes a first switch tube, a second switch tube, and a third switch tube; The control end of the first switch tube is connected to the connection node of the first diode and the second diode through a first current limiting resistor; One end of the switch path of the first switch tube is connected to the driving power supply through a second current limiting resistor, and the other end of the switch path of the first switch tube is grounded; One end of the switch path of the first switch tube is connected to the control end of the second switch tube, one end of the switch path of the second switch tube is connected to the driving power supply through a voltage divider circuit, and the other end of the switch path of the second switch tube is grounded; The voltage dividing node of the voltage dividing circuit is connected to the control end of the third switch tube; one end of the switch path of the third switch tube is connected to the driving power supply, and the other end of the switch path of the third switch tube is connected to the power supply end of the load switch.

3. The load switch power supply control circuit according to claim 2, characterized in that: The voltage-dividing circuit comprises a first voltage-dividing resistor and a second voltage-dividing resistor, one end of the first voltage-dividing resistor is connected to one end of the switch path of the second switch tube, the other end of the first voltage-dividing resistor is connected to one end of the second voltage-dividing resistor, and the other end of the second voltage-dividing resistor is connected to the driving power supply; A connection node between the first voltage-dividing resistor and the second voltage-dividing resistor is connected to a control end of the third switch tube.

4. The load switch power supply control circuit according to claim 1, characterized in that: The load switch power supply control circuit also includes a control unit; The first detection terminal of the control unit is connected to one end of the first gate switch through a third current limiting resistor; The second detection terminal of the control unit is connected to one end of the second gate switch through a fourth current limiting resistor; The output end of the control unit is connected to the control end of the switch circuit through a fifth current limiting resistor.

5. The load switch power supply control circuit according to claim 4, characterized in that: The first detection terminal of the control unit is grounded via a first filter capacitor; The second detection terminal of the control unit is grounded through a second filter capacitor.

6. The load switch power supply control circuit according to claim 2, characterized in that: The control end of the first switch tube is grounded through a third filter capacitor.

7. The load switch power supply control circuit according to claim 2, characterized in that: The other end of the switch path of the third switch tube is grounded through a fourth filter capacitor.

8. The load switch power supply control circuit according to claim 2, characterized in that: The first switch tube is an NPN transistor, the second switch tube is an NPN transistor, and the third switch tube is a PMOS tube.

9. Electrical equipment, characterized in that: include: Box; A door body, which is arranged on the box body; A strong electric load is arranged in the box; A load switch connected in series in a power supply circuit of the high-voltage load; The load switch power supply control circuit according to any one of claims 1 to 8, wherein the other end of the switch path of the switch circuit is connected to the power supply end of the load switch.

10. The electrical equipment according to claim 9, characterized in that: The load switch is a relay; The power supply end of the coil of the relay is connected to the other end of the switch path of the switch circuit of the load switch power supply control circuit; The normally open contact of the relay is connected in series in the power supply circuit of the high-current load.

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