Slow start circuit and cleaning robot

Abstract

The embodiment discloses a slow start circuit, which comprises a first capacitor, a first switch circuit, a second switch circuit and a feedback circuit, the first switch circuit is connected between a direct current power supply and a load, the output end of the first switch circuit is connected with the control end of the feedback circuit, and the feedback circuit is connected between the control end of the second switch circuit and the load. The second switching circuit is connected between the direct-current power supply and the load; the first switch circuit is used for outputting a voltage signal with a gradually increased voltage value when the first capacitor is charged, and is used for cutting off the connection between the direct-current power supply and the control end of the second switch circuit when the first capacitor is discharged; the second switching circuit is used for outputting a voltage signal for power supply to the load when the control end receives the voltage signal meeting the first set condition; the feedback circuit is used for controlling the second switching circuit to be switched on and controlling the second switching circuit to be switched off when the load is short-circuited; the first set condition includes that the voltage value is greater than the first set voltage value.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and relates to but is not limited to a slow-start circuit and a cleaning robot. Background Art

[0002] In the related art, when some high-power devices are started, the load current may reach a very high value instantly. The large-flow load end usually generates a large energy storage capacitor due to the current mutation. The capacitor will be charged at the moment the power supply is turned on, resulting in a large instantaneous current and causing damage to the switching circuit or power supply. Relying on the turn-on time of the Metal-Oxide-Semiconductor (MOS) or Insulate-Gate Bipolar Transistor (IGBT) to achieve circuit slow start often causes the slow start time to be insufficient or too long, resulting in the burning of the MOS tube. Utility Model Content

[0003] Embodiments of the present application provide a slow-start circuit and a cleaning robot.

[0004] A slow start circuit provided in an embodiment of the present application includes:

[0005] A first capacitor, a first switch circuit, a second switch circuit and a feedback circuit, wherein the first switch circuit is connected between a DC power supply and a load, an output end of the first switch circuit is connected to a control end of the feedback circuit, the feedback circuit is connected between the control end of the second switch circuit and the load, and the second switch circuit is connected between the DC power supply and the load;

[0006] The first switch circuit is used to output a voltage signal with a gradually increasing voltage value when the first capacitor is charged, and is used to cut off the connection between the DC power supply and the control end of the second switch circuit when the first capacitor is discharged; the second switch circuit is used to output a voltage signal for power supply to the load when the control end receives a voltage signal that meets a first set condition; the feedback circuit is used to control the second switch circuit to be turned on, and to control the second switch circuit to be turned off when the load is short-circuited; the first set condition includes a voltage value greater than a first set voltage value.

[0007] In some embodiments, one end of the first capacitor is connected to the control end of the first switch circuit, and the other end is used to receive a high level signal or a low level signal.

[0008] It can be seen that when the first capacitor receives a high level, the first capacitor is charged and the first switch circuit is turned on. When one end of the first capacitor receives a low level, the first capacitor is discharged and the first switch circuit is turned off, thereby the second switch circuit connected to the first switch circuit is also turned off, which greatly reduces the impact current at the moment the second switch circuit is turned on, and at the same time can control the circuit's slow start time not to be too long or too short.

[0009] In some embodiments, the first switching circuit includes at least one switching device and a thermistor, and the at least one switching device is used to output a voltage signal with a gradually increasing voltage value through the thermistor when the first capacitor is charged.

[0010] It can be seen that when the first capacitor is charged, at least one switching device in the first switching circuit is turned on, and a voltage signal with a gradually increasing voltage value is output through the thermistor. The thermistor here is equivalent to a slow-start resistor. Because under the same current, the package of the thermistor is smaller than that of a conventional resistor and has better heat resistance, the application of thermistors can effectively reduce the package of the first switching circuit and achieve a better slow-start effect.

[0011] In some embodiments, the at least one switching device includes a first switching device and a second switching device, the control end of the first switching device is connected to the first capacitor, and the second switching device is connected between the DC power supply and the thermistor; the first switching device is used to control the second switching device to turn on when the first capacitor is charged.

[0012] In some embodiments, the second switching device is a first MOS tube, and the first switching circuit also includes a first voltage divider circuit connected to the first switching device; the branch formed by the first switching device and the first voltage divider circuit is connected between a DC power supply and ground, and the first voltage divider circuit is used to provide a driving voltage to the first MOS tube.

[0013] It can be seen that when the second switching device is the first MOS tube, using the above circuit, when the first capacitor is discharged or receives a low-level signal, the first MOS tube connected to the first capacitor is turned off, which greatly reduces the problem of damage to the first MOS tube caused by the instantaneous large current when the circuit is turned on.

[0014] In some embodiments, the first switching device is a transistor.

[0015] In some embodiments, the second switching circuit includes a third switching device, and the control end of the second switching circuit is the output end of the feedback circuit; the third switching device is connected between the DC power supply and the load, and the feedback circuit is used to control the third switching device to be turned on when the voltage signal meets the second set condition; the second set condition includes a voltage value greater than a second set voltage value.

[0016] In some embodiments, the slow start circuit further includes a second voltage divider circuit, the output end of the first switch circuit is connected to the control end of the feedback circuit through the second voltage divider circuit, and the second voltage divider circuit is used to control the feedback circuit to be turned on or off.

[0017] In some embodiments, the third switching device is a second MOS tube, and the second switching circuit also includes a third voltage divider circuit connected to the feedback circuit; the branch formed by the feedback circuit and the second voltage divider circuit is connected between a DC power supply and ground, and the third voltage divider circuit is used to provide a driving voltage to the second MOS tube.

[0018] It can be seen that when the first capacitor controls the first switch circuit to be turned on, the first switch circuit can control the second switch circuit to be turned on. When the third switch device in the second switch circuit is a second MOS tube, using the above circuit, when the first capacitor is discharged or receives a low-level signal, the first MOS tube in the first switch circuit connected to the first capacitor is turned off, and the second MOS tube connected to the first switch circuit is also turned off, which greatly reduces the problem of damage to the second MOS tube due to the instantaneous large current when the circuit is turned on.

[0019] In some embodiments, the feedback circuit includes a three-terminal regulator.

[0020] An embodiment of the present application also provides a cleaning robot, which includes the above-mentioned circuit.

[0021] The embodiment of the present application provides a slow-start circuit and a cleaning robot, including a first capacitor, a first switch circuit, a second switch circuit and a feedback circuit. The first switch circuit can be controlled by the first capacitor, the feedback circuit can be controlled by the first switch circuit, and the second switch circuit can be controlled by the feedback circuit, thereby realizing a slow-start function of the circuit. In the slow-start circuit provided in the embodiment of the present application, when the first capacitor receives a low-level signal, the first switch circuit controlled by the first capacitor is turned off, and further, the second switch circuit controlled by the first switch circuit is also turned off, which greatly reduces the influence of the large impact current generated at the moment of circuit conduction; in addition, according to the charging and discharging characteristics of the first capacitor, when the first capacitor is discharged, the first switch circuit controlled by the first capacitor is automatically turned off, and the second switch circuit controlled by the first switch circuit is also automatically turned off. Therefore, the slow-start circuit provided in the embodiment of the present application can automatically disconnect the circuit by discharging the first capacitor, avoiding the problem of damage to the components in the circuit due to insufficient or too long slow-start time, thereby protecting the circuit and effectively protecting the components in the circuit from being damaged by the instantaneous large current when the equipment is turned on; when the load end is short-circuited, the second switch circuit can be controlled to be turned off through the feedback circuit to achieve short-circuit protection of the circuit; the embodiment of the present application also provides a cleaning robot, including the above-mentioned circuit, and can achieve the slow-start and load protection functions of the cleaning robot circuit through the above-mentioned circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a slow start circuit connection provided in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of a first switch circuit connection provided in an embodiment of the present application;

[0024] Figure 3 A schematic diagram of a second switch circuit connection provided in an embodiment of the present application;

[0025] Figure 4 A slow start circuit diagram is provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application are further elaborated in detail below in conjunction with the drawings and embodiments. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0027] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0028] The terms "first / second / third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first / second / third" can be interchanged with a specific order or sequence where permitted so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing this application and are not intended to limit this application.

[0030] The slow start circuit is widely used in the circuit design of various high-power electronic devices. For example, various motors, inverters, power supplies, etc. often need to use a slow start circuit to control the current impact at the startup moment. In addition, the slow start circuit is also widely used in some occasions where it is necessary to protect the power supply and equipment circuit components to improve the reliability and life of the system. In a general circuit, when the circuit is started, the load current may reach a very high value instantaneously. At the same time, the large current load usually generates a large energy storage capacitor due to the current mutation. At the moment when the power supply is turned on, the energy storage capacitor will be charged, resulting in damage to the power supply or device in the switching circuit, and even short circuit and other faults. Therefore, a slow start circuit is often used in electronic circuits to reduce the current impact caused by the startup moment. In the related art, the slow start circuit generally relies on the opening time of the MOS tube or IGBT to realize the slow start of the circuit, but this often causes the slow start time to be insufficient or too long, resulting in the burning of the MOS tube.

[0031] The embodiment of the present application provides a slow-start circuit that can realize a large current slow-start function, can avoid the problem of device damage in the circuit due to insufficient slow-start time or too long slow-start time, and effectively protect the entire circuit.

[0032] The following is a further detailed description of the embodiments of the present application in conjunction with the accompanying drawings and examples. It should be understood that the embodiments provided herein are only used to explain the embodiments of the present application and are not intended to limit the embodiments of the present application. In addition, the embodiments provided below are partial embodiments for implementing the present application, rather than providing all embodiments for implementing the present application. In the absence of conflict, the technical solutions recorded in the embodiments of the present application can be implemented in any combination.

[0033] It should be noted that in the embodiments of the present application, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, including not only the elements explicitly stated, but also other elements not explicitly listed. In the absence of further restrictions, the elements defined by the sentence "include ..." do not exclude the presence of other related elements in the inclusion of the elements.

[0034] A slow-start circuit provided in an embodiment of the present application includes a series of connection designs of circuits and devices, but the connection designs of circuits and devices provided in an embodiment of the present application are not limited to the recorded connection designs.

[0035] Figure 1 A schematic diagram of a slow start circuit connection provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the slow start circuit includes a first capacitor C1, a first switch circuit 101, a second switch circuit 102 and a feedback circuit 104. The first switch circuit 101 is connected between a DC power supply VDD and a load 103. The output end of the first switch circuit 101 is connected to a control end of the feedback circuit 104. The feedback circuit 104 is connected between the control end of the second switch circuit 102 and the load 103. The second switch circuit 102 is connected between the DC power supply VDD and the load 103.

[0036] The first switch circuit 101 is used to output a voltage signal with a gradually increasing voltage value when the first capacitor C1 is charged, and is used to cut off the connection between the DC power supply VDD and the control end of the second switch circuit 102 when the first capacitor C1 is discharged; the second switch circuit 102 is used to output a voltage signal for power supply to the load 103 when the control end receives a voltage signal that meets the first set condition; the feedback circuit 104 is used to control the second switch circuit 102 to be turned on, and to control the second switch circuit 102 to be turned off when the load is short-circuited; the first set condition includes that the voltage value is greater than the first set voltage value.

[0037] Here, the charging and discharging characteristics of the first capacitor are utilized. When the first capacitor C1 is charging, the circuit is turned on and the power supply supplies power to the first switch circuit 101. When the first capacitor C1 is discharging, the circuit is disconnected and the voltage at the input end of the first switch circuit 101 is 0V. The circuit completes the slow start function. The feedback circuit 104 can also feedback voltage from the load 103 and control the second switch circuit 102 to shut down when the load is short-circuited, thereby achieving short-circuit protection.

[0038] In some embodiments, one end of the first capacitor C1 is connected to the control end of the first switch circuit 101 , and the other end is used to receive a high level signal or a low level signal.

[0039] According to the description of the function of the first capacitor in the above embodiment, when the first capacitor C1 receives a high level signal, the first capacitor C1 is charged and the first switch circuit 101 is turned on; when the first capacitor C1 receives a low level signal, the first capacitor C1 is discharged and the first switch circuit 101 is turned off.

[0040] In some embodiments, the first switch circuit 101 includes at least one switch device and a thermistor, and the at least one switch device is used to output a voltage signal with a gradually increasing voltage value through the thermistor when the first capacitor C1 is charged.

[0041] Thermistor is a sensor resistor whose resistance changes with temperature. In this embodiment, thermistor and at least one switch device are used to form the first switch circuit 101. Thermistor here is equivalent to a slow-start resistor in the slow-start circuit given in this embodiment. Its characteristic is that the larger the current flowing through the thermistor, the smaller the resistance of the thermistor. Therefore, under the same current, the package of thermistor is smaller than that of conventional resistors and has better heat resistance. Since thermistors usually change their resistance slowly with temperature changes, and the maximum impact current time when the power tube is turned on is short, when thermistors are used as slow-start resistors, the maximum impact current can be set to be less than half of the maximum continuous current that the first switch circuit 101 can withstand.

[0042] In some embodiments, at least one switching device includes a first switching device and a second switching device, the control end of the first switching device is connected to the first capacitor C1, and the second switching device is connected between the DC power supply VDD and the thermistor; the first switching device is used to control the second switching device to turn on when the first capacitor C1 is charged.

[0043] like Figure 2 As shown, Figure 2 A first switch circuit connection schematic diagram is shown, and a possible connection mode of at least one switch device is shown in the first switch circuit connection schematic diagram, wherein when the first capacitor C1 receives a high-level signal, the first capacitor C1 is in a charging state, and the first switch device 201 connected to the first capacitor C1 is turned on, and the second switch device 202 can be controlled to be turned on by the first switch device 201. The output end of the second switch device 202 is connected to the thermistor R1. When the first switch device 201 controls the second switch device 202 to be turned on, a current flows through the second switch device 202 to the thermistor R1. According to the above description of the characteristics of the thermistor, the thermistor R1 is equivalent to a slow-start resistor at this time.

[0044] In some embodiments, the second switching device 202 is a first MOS tube, and the first switching circuit 101 also includes a first voltage divider circuit connected to the first switching device 201; the branch formed by the first switching device 201 and the first voltage divider circuit is connected between the DC power supply VDD and the ground, and the first voltage divider circuit is used to provide a driving voltage to the first MOS tube.

[0045] It is provided here that the second switching device 202 can be a MOS tube. Specifically, the first MOS tube can be an N-channel metal oxide semiconductor tube (N-Metal-Oxide-Semiconductor, NMOS) or a P-channel metal oxide semiconductor tube (P-Metal-Oxide-Semiconductor, PMOS). The present application does not limit the type of the first MOS tube. For example, when the first MOS tube is a first NMOS tube, a DC power supply may be connected to the gate of the first NMOS tube, the source of the first NMOS tube may be grounded, and a positive potential difference may be generated between the gate and the source of the first NMOS tube to turn on the first NMOS tube; when the first MOS tube is a first PMOS tube, a DC power supply may be connected to the source of the first PMOS tube, the gate of the first PMOS tube may be grounded, and a negative potential difference may be generated between the gate and the source of the first PMOS tube to turn on the first PMOS tube; a person skilled in the art may know that since different types of MOS tubes have different conduction conditions, the circuit may be designed and connected accordingly; therefore, on the basis of the present embodiment, designs that use different types of MOS tubes and turn on the MOS tubes through different connection circuits are all within the protection scope of the present utility model.

[0046] In some embodiments, the first switching device is a transistor.

[0047] In this embodiment, the first switch device 201 is a triode. In combination with the circuit provided in the above embodiment, a connection mode of the first switch circuit 101 may include a triode, a first MOS tube and a thermistor R1, wherein the triode is driven to be turned on by turning on the first capacitor C1, and the turned-on triode provides a driving voltage to the first MOS tube through the first voltage divider circuit. When the first MOS tube is driven, current flows through the thermistor, and the current is transmitted to the next stage circuit through the thermistor.

[0048] The transistor provided here can be an NPN transistor or a PNP transistor. The present application does not limit the type of transistor. For example, when the first switch device 201 is an NPN transistor, the base of the NPN transistor is connected to the output end of the first capacitor C1, and when the first capacitor C1 is charged, the current of the NPN transistor flows from the collector to the emitter. At this time, the first voltage divider circuit is connected to the collector of the NPN transistor, and there is a voltage difference on the first voltage divider circuit. According to the voltage difference of the voltage divider circuit, the first MOS tube can be driven to turn on; when the first switch device 201 is a PNP transistor, the base of the PNP transistor is connected to the output end of the first capacitor C1, and when the first capacitor C1 is discharged, the current of the PNP transistor flows from the emitter to the collector. At this time, the first voltage divider circuit is connected to the emitter of the PNP transistor, and there is a positive voltage difference on the first voltage divider circuit. According to the voltage difference of the voltage divider circuit, the first MOS tube can be driven to turn on.

[0049] In some embodiments, the second switch circuit 102 includes a third switch device, and the control end of the second switch circuit 102 is the output end of the feedback circuit 104; the third switch device is connected between the DC power supply VDD and the load 103, and the feedback circuit 104 is used to control the third switch device to be turned on when the voltage signal meets the second set condition; the second set condition includes a voltage value greater than a second set voltage value.

[0050] like Figure 3 As shown, Figure 3 A connection schematic diagram of a second switch circuit 102 is shown, the second switch circuit 102 includes a third switch device 301, wherein the control end of the second switch circuit 102 is the output end of the feedback circuit 104, the control end of the feedback circuit 104 is connected to the output end of the thermistor R1, the third switch device 301 is connected between the DC power supply VDD and the load 103, when the voltage value output by the feedback circuit 104 is greater than the second preset voltage value, the third switch device 301 is turned on, and the load circuit is turned on.

[0051] In some embodiments, the slow start circuit further includes a second voltage divider circuit, the output end of the first switch circuit 101 is connected to the control end of the feedback circuit 104 through the second voltage divider circuit, and the second voltage divider circuit is used to control the on or off of the feedback circuit 104.

[0052] This embodiment provides a control method for the feedback circuit 104, wherein the first switch circuit 101 is connected to the feedback circuit 104 via the second voltage divider circuit, and controls the on or off state of the feedback circuit 104 by controlling the voltage divider size of the second voltage divider circuit. Furthermore, the first switch circuit 101 can control the on or off state of the second switch circuit 102 by controlling the on or off state of the feedback circuit 104.

[0053] In some embodiments, the third switching device 301 is a second MOS tube, and the second switching circuit 102 also includes a third voltage divider circuit connected to the feedback circuit 104; the branch formed by the feedback circuit 104 and the second voltage divider circuit is connected between the DC power supply VDD and the ground, and the third voltage divider circuit is used to provide a driving voltage to the second MOS tube.

[0054] Here, the third switch device 301 can be a second MOS tube, specifically, the second MOS tube can be an NMOS tube or a PMOS tube, and the present application does not limit the type of the second MOS tube. For example, when the second MOS tube is a second NMOS tube, the gate of the second NMOS tube can be connected to a DC power supply, the source of the second NMOS tube can be grounded, and a positive potential difference can be generated between the gate and the source of the second NMOS tube to turn on the second NMOS tube; when the second MOS tube is a second PMOS tube, the source of the second PMOS tube can be connected to a DC power supply, the gate of the second PMOS tube can be grounded, and a negative potential difference can be generated between the gate and the source of the second PMOS tube to turn on the second PMOS tube; those skilled in the art can know that according to the conduction conditions of different MOS tubes, the circuit can be designed and connected accordingly, therefore, on the basis of this embodiment, the design of turning on the MOS tube by applying different types of MOS tubes and using different connection circuits is within the protection scope of the present utility model.

[0055] In some embodiments, the feedback circuit 104 includes a three-terminal regulator.

[0056] A three-terminal voltage regulator is a semiconductor device with a very high resistance before the critical reverse breakdown voltage arrives. When the three-terminal voltage regulator is in reverse breakdown, it can exhibit voltage stabilization characteristics within a certain current range. The conduction characteristics of the three-terminal voltage regulator are utilized here. When the voltage at the voltage dividing point of the second voltage dividing circuit just exceeds the conduction voltage of the three-terminal voltage regulator, the three-terminal voltage regulator is turned on. Furthermore, the three-terminal voltage regulator outputs current to the third switching device.

[0057] The embodiment of the present application provides a slow-start circuit, which can use a first capacitor to control the on and off of the slow-start circuit, and realize the slow-start function through two switch circuits, thereby avoiding the problem of damage to components in the circuit due to insufficient slow-start time or too long slow-start time; when the load is short-circuited, the second switch circuit is controlled to be turned off through the feedback circuit, thereby realizing protection of the circuit and effectively protecting the components in the circuit.

[0058] Below Figure 4 Taking the example of FIG. 1 as an example, a specific circuit connection for the slow start circuit in the above application embodiment is provided.

[0059] The present application embodiment provides a specific slow start circuit connection method, such as Figure 4As shown in FIG. 1 , a slow start circuit diagram is shown. Figure 4 In the circuit diagram shown, a DC power supply VDD is connected to a power supply, a third switch device Q1 is a main MOS, the parameters of the third switch device Q1 must meet the load current carrying capacity, the DC power supply VDD is connected to the source of the third switch device Q1, and the load terminal is connected to the drain of the third switch device Q1; the second resistor R2 and the fifth resistor R5 are connected in series to form a third voltage divider circuit 403, one end of the second resistor R2 is connected to the source of the third switch device Q1, and the other end is connected to the gate of the third switch device Q1; one end of the fifth resistor R5 is connected to the gate of the third switch device Q1 and the second resistor R2, and the other end is connected to the 2nd pin of the three-terminal regulator U1; the sixth resistor R6 and the seventh resistor R7 are connected in series to form a second voltage divider circuit 402, one end of the sixth resistor R6 is connected to the output end of the second capacitor C2 and the thermistor R1, and the other end is connected to the seventh resistor R7 and the input end of the three-terminal regulator U1; one end of the seventh resistor R7 is connected to the sixth resistor R6 and the input end of the three-terminal regulator U1, and the other end is grounded; the second capacitor C2 is an equivalent capacitor at the load end, that is, the second capacitor C2 does not actually exist. The first resistor R1 is a pre-charging resistor, wherein the first resistor R1 can be a thermistor; the second switch device Q2 is a pre-charging MOS, the source of the second switch device Q2 is connected to the DC power supply VDD, and the drain of the second switch device Q2 is connected to the first resistor R1; the third resistor R3 and the fourth resistor R4 are connected in series to form a first voltage divider circuit 401, one end of the third resistor R3 is connected to the source of the second switch device Q2, and the other end is connected to the gate of the second switch device Q2 and the fourth resistor R4; one end of the fourth resistor R4 is connected to the gate of the second switch device Q2 and the third resistor R3, and the other end is connected to the collector of the first switch device Q3; the first switch device Q3 is a control transistor of the second switch device Q2, the collector of the first switch device Q3 is connected to the fourth resistor R4, the emitter of the first switch device Q3 is grounded, and the base of the first switch device Q3 is connected to the output end of the first capacitor C1; the first capacitor C1 is a turn-on capacitor of the first switch device Q3, the output end of the first capacitor C1 is connected to the base of the first switch device Q3, and the input end is connected to the control pin.

[0060] Further, in Figure 4 In the circuit shown, the first switch device Q3 can be an NPN transistor, the third switch device Q1 and the second switch device Q2 can be PMOS tubes, and the three-terminal regulator U1 can be implemented by referring to the TL431 three-terminal regulator. When powering the subsequent load, the pre-charge circuit is first turned on, and the second switch device Q2 is turned on, wherein the parameters of the second switch device Q2 can be selected according to the resistance value of the first resistor R1. When the first resistor R1 is a thermistor, the resistance value of the first resistor R1 is R1=VDD / I, wherein I is the magnitude of the inrush current to be limited.

[0061] exist Figure 4In the figure, the ON / OFF terminal is the microcontroller control pin. When the power is supplied to the subsequent load, the ON / OFF output is high level, and the first capacitor C1 is charged. At the same time, the 1st pin of the first switch device Q3, that is, the base potential is high, and the first switch device Q3 is turned on. After the first switch device Q3 is turned on, according to the NPN transistor conduction principle, the current flows from the third resistor R3 to the fourth resistor R4. Therefore, the third resistor R3 and the fourth resistor R4 will have a voltage division at the connection, resulting in a potential difference between the two ends of the third resistor R3. At this time, the source voltage of the second switch device Q2 is higher than the gate voltage, and the gate-source of the second switch device Q2 has a negative potential difference, and the second switch device Q2 is turned on. After the second switch device Q2 is turned on, the DC power supply VDD generates an instantaneous current, and the load becomes capacitive, that is, at this time, the DC power supply VDD starts to charge the second capacitor C2 of the subsequent load circuit through the first resistor R1, and the maximum impact current limit at this time is VDD / R1. When the voltage of the subsequent load reaches 3 / 4 of the power supply voltage, the divided voltage of the sixth resistor R6 and the seventh resistor R7 just exceeds the conduction voltage of the three-terminal voltage regulator U1, and the three-terminal voltage regulator U1 is turned on; after the three-terminal voltage regulator U1 is turned on, the third voltage divider circuit 403 composed of the second resistor R2 and the fifth resistor R5 has current passing through it, and the current direction flows from the second resistor R2 to the fifth resistor R5. At this time, there is a potential difference between the two ends of the second resistor R2, so that the source voltage of the third switch device Q1 is higher than the gate voltage, and the gate source of the third switch device Q1 has a negative potential difference, and the third switch device Q1 is turned on. After the third switch device Q1 is turned on, it continues to supply power to the subsequent load, and the current at this time is the load current. When the first capacitor C1 is fully charged, the base potential of the first switch device Q3 becomes 0V, the first switch device Q3 is turned off, and the second switch device Q2 is turned off accordingly. This process greatly reduces the impact current of the third switch device Q1 when it is turned on.

[0062] When the third switch device Q1 is turned on, when the load is abnormally short-circuited, the voltage of the load will drop to 0 in a very short time. At this time, the voltage divided by the sixth resistor R6 and the seventh resistor R7 is less than the reference voltage of the three-terminal regulator U1, and the three-terminal regulator U1 is turned off. After the three-terminal regulator U1 is turned off, there is no voltage divided at the connection between the second resistor R2 and the fifth resistor R5, so there is no voltage difference on the second resistor R2, resulting in no gate-source negative voltage of the third switch device Q1. The third switch device Q1 is turned off. After the third switch device Q1 is turned off, the load has no voltage and will not repeatedly turn on the third switch device Q1, thereby protecting the risk of the third switch device Q1 being burned out due to a load short circuit. When the short circuit fault is removed, the ON / OFF terminal needs to be reopened.

[0063] Figure 4 The circuit structure shown in the figure is only one of the slow start circuits of the present application. Figure 4When the second switch device Q2 in the embodiment is an NMOS tube, according to the conduction characteristics of the NMOS tube, the connection between pins 2 and 3 of the second switch device Q2 needs to be reversed, that is, the drain of the second switch device Q2 needs to be connected to the DC power supply VDD, and the source of the second switch device Q2 needs to be connected to the first resistor R1. Therefore, when the second switch device is an NMOS tube, the gate voltage provided by the first voltage divider circuit 401 to the second switch device Q2 needs to be greater than the source voltage, so that the second switch device Q2 is turned on; when Figure 4 When the third switch device in the circuit is an NMOS tube, according to the conduction characteristics of the NMOS tube, the connection between pins 2 and 3 of the third switch device Q2 needs to be flipped, that is, the drain of the third switch device Q2 needs to be connected to the DC power supply VDD, and the source of the third switch device Q2 needs to be connected to the load. At the same time, the gate voltage provided to the third switch device Q2 by the third voltage divider circuit 403 needs to be greater than the source voltage, so that the third switch device Q2 is turned on.

[0064] In addition, according to the conduction condition of the MOS tube, the composition of the first voltage divider circuit 401, the second voltage divider circuit 402 and the third voltage divider circuit 403 in the present application is not necessarily limited to the following: Figure 4 As shown in the voltage-dividing structure composed of series resistors, a person skilled in the art can know that any circuit connection with voltage-dividing characteristics can replace the voltage-dividing circuit in the present application as long as the conduction condition of the MOS tube is met.

[0065] This embodiment provides a specific connection method of a slow start circuit. By turning on the first capacitor, the slow start function is controlled to avoid the problem that the load current increases instantaneously when some high-power devices are started, causing the components in the circuit to be damaged. At the same time, the problem that the circuit components are damaged due to insufficient slow start time or too long slow start time is avoided. In addition, when the load is short-circuited, the circuit connection can be effectively cut off by controlling the above-mentioned feedback circuit, and the third switch component in the protection circuit will not be started repeatedly, thereby extending the service life of the third switch component. In the circuit provided in this embodiment, the specific components used include resistors, capacitors, MOS tubes, triodes and three-terminal regulators. Compared with the general slow start circuit design, IGBT, current sampling resistors, operational amplifiers and current detection chips are not required. Therefore, the functions of realizing large current slow start and short circuit protection at low cost are achieved, and it has strong practicality.

[0066] The embodiment of the present application also provides a cleaning robot, which includes the above-mentioned circuit and can realize the soft start and short circuit protection functions of the circuit in the cleaning robot through the above-mentioned circuit design.

[0067] It should be understood that the reference to "one embodiment" or "an embodiment" throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. The serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0068] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, article, etc. that includes a series of elements includes not only the listed elements, but also other elements that are not explicitly listed.

[0069] In the several embodiments provided in this application, it should be understood that the disclosed devices or components can be implemented in other ways. The embodiments described above are only exemplary. For example, the voltage divider circuit is only a logical function. There may be other connection modes in actual implementation, such as: multiple devices or circuits can constitute a voltage divider circuit, or can be integrated into another system, or some features can be ignored or not executed.

[0070] The above is only an implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A slow start circuit, characterized in that: include: A first capacitor, a first switch circuit, a second switch circuit and a feedback circuit, wherein the first switch circuit is connected between a DC power supply and a load, an output end of the first switch circuit is connected to a control end of the feedback circuit, the feedback circuit is connected between the control end of the second switch circuit and the load, and the second switch circuit is connected between the DC power supply and the load; The first switch circuit is used to output a voltage signal with a gradually increasing voltage value when the first capacitor is charged, and is used to cut off the connection between the DC power supply and the control end of the second switch circuit when the first capacitor is discharged; the second switch circuit is used to output a voltage signal for power supply to the load when the control end receives a voltage signal that meets a first set condition; the feedback circuit is used to control the second switch circuit to be turned on, and to control the second switch circuit to be turned off when the load is short-circuited; the first set condition includes a voltage value greater than a first set voltage value.

2. The circuit according to claim 1, characterized in that One end of the first capacitor is connected to the control end of the first switch circuit, and the other end is used to receive a high level signal or a low level signal.

3. The circuit according to claim 1, characterized in that The first switch circuit includes at least one switch device and a thermistor. The at least one switch device is used to output a voltage signal with a gradually increasing voltage value through the thermistor when the first capacitor is charged.

4. The circuit according to claim 3, characterized in that The at least one switching device includes a first switching device and a second switching device, wherein the control end of the first switching device is connected to the first capacitor, and the second switching device is connected between the DC power supply and the thermistor; the first switching device is used to control the second switching device to be turned on when the first capacitor is charged.

5. The circuit according to claim 4, characterized in that The second switching device is a first MOS tube, and the first switching circuit also includes a first voltage divider circuit connected to the first switching device; the branch formed by the first switching device and the first voltage divider circuit is connected between a DC power supply and ground, and the first voltage divider circuit is used to provide a driving voltage to the first MOS tube.

6. The circuit according to claim 5, characterized in that The first switching device is a triode.

7. The circuit according to claim 1, characterized in that The second switching circuit includes a third switching device, and the control end of the second switching circuit is the output end of the feedback circuit; the third switching device is connected between the DC power supply and the load, and the feedback circuit is used to control the third switching device to be turned on when the voltage signal meets the second set condition; the second set condition includes a voltage value greater than a second set voltage value.

8. The circuit according to claim 7, characterized in that The slow start circuit further includes a second voltage divider circuit, the output end of the first switch circuit is connected to the control end of the feedback circuit through the second voltage divider circuit, and the second voltage divider circuit is used to control the feedback circuit to be turned on or off.

9. The circuit according to claim 8, characterized in that The third switching device is a second MOS tube, and the second switching circuit also includes a third voltage divider circuit connected to the feedback circuit; the branch formed by the feedback circuit and the second voltage divider circuit is connected between a DC power supply and ground, and the third voltage divider circuit is used to provide a driving voltage to the second MOS tube.

10. The circuit according to claim 7, characterized in that The feedback circuit includes a three-terminal regulator.

11. A cleaning robot, characterized in that: The cleaning robot comprises the circuit according to any one of claims 1-10.

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