Control circuit and electric tool

Abstract

The invention discloses a control circuit and an electric tool, and the control circuit comprises a DC controller which is provided with a DC input interface and a DC output interface, and the DC input interface is connected with a DC power supply; the change-over switch circuit is connected with the direct-current output interface and an alternating-current power supply, and the change-over switch circuit is used for switching the alternating-current power supply and the direct-current power supply; the alternating current controller is provided with a first input interface, the first input interface is connected with the output end of the change-over switch circuit, the alternating current controller is used for rectifying and boosting the direct current or the alternating current input by the first input interface and then outputting the direct current or the alternating current, and the boosted voltage of the direct current or the alternating current is consistent; the consistency of the output voltage of the control circuit in the direct current working mode and the alternating current working mode can be improved, so that the consistency of the output parameters and the performance of the electric tool applying the control circuit in the direct current working mode and the alternating current working mode is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of control circuits, and in particular to control circuits and electric tools. Background Art

[0002] In real life, high-pressure cleaners are widely used in industrial dust removal, urban street cleaning, urban crust removal, car washing, building exterior walls, floors, baths, swimming pools, doors and windows, floors, toilets, oil stains, and corners that are difficult to clean manually. In the field of industrial or daily cleaning, traditional cleaning methods are often time-consuming and labor-intensive, and the results are not satisfactory. Modern society's requirements for efficiency and effectiveness are constantly increasing. Therefore, high-pressure cleaners are becoming an important tool for cleaning operations with their advantages of saving time and effort, high efficiency and speed.

[0003] With the development of science and technology, people began to study how to combine the advantages of AC and DC, and adopted a hybrid power supply method to better meet various application requirements. They each have their own advantages and disadvantages and are suitable for different occasions. In order to pursue multiple system power supply, flexible switching, simple operation, etc., the single power supply mode is upgraded to an AC / DC dual-use platform to achieve more uses, meet different customer needs, and improve customer satisfaction. However, the current products still have shortcomings, as follows:

[0004] Currently, the AC / DC dual-purpose power tools on the market are in AC power working mode. After rectification by a rectifier bridge, the power is converted into high-voltage DC and directly output to the motor end. They do not have a power factor correction circuit, and the switching power supply efficiency is low. The current harmonic distortion is large and the power factor is low, generally between 0.5 and 0.7. This will cause a large phase difference between current and voltage, resulting in insufficient energy utilization, increasing reactive power in the power grid, which may cause additional burden on the power grid and affect the stability and efficiency of the power grid.

[0005] In the DC power supply working mode, the DC power supply is connected to the back end of the rectifier bridge. Compared with the voltage of the AC power after rectification by the rectifier bridge, the DC voltage is small. For example, after using a 60V double pack in series, the input is 120V DC, and the output is also 120V DC. The input 120V AC becomes 170V DC after rectification by the rectifier bridge, which is a 50V difference. The DC working mode will cause the motor speed and the overall performance parameters to become smaller, and the performance indicators of the AC working mode will not be achieved. That is, the output performance parameters of the power tool in the two different power supply modes are inconsistent. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a control circuit and an electric tool, which are used to solve the problem that the output performance parameters of the electric tool in the prior art are inconsistent under AC and DC power supply modes.

[0007] To achieve the above objectives and other related objectives, the present application provides a control circuit, including:

[0008] A DC controller having a DC input interface and a DC output interface, wherein the DC input interface is connected to a DC power supply;

[0009] A switching circuit, the switching circuit is connected to the DC output interface and the AC power supply, and the switching circuit is used to switch the AC and DC power supplies;

[0010] The AC controller has a first input interface, which is connected to the output end of the switching circuit. The AC controller is used to rectify and boost the DC or AC input from the first input interface and then output it, and the voltages of the two are consistent after boosting.

[0011] In an optional embodiment of the present application, the AC controller includes a rectifier circuit, a power factor correction circuit, a first power supply circuit and a first control unit;

[0012] The input end of the rectifier circuit is connected to the first input interface, and the rectifier circuit is used to rectify the direct current or alternating current input by the first input interface;

[0013] The input end of the power factor correction circuit is connected to the output end of the rectifier circuit, and the power factor correction circuit is used to boost the rectified direct current or alternating current and then output it;

[0014] The input end of the first power supply circuit is connected to the output end of the power factor correction circuit, and the first power supply circuit is used to convert the output voltage of the power factor correction circuit into a first power supply voltage to provide a working voltage to the circuits in the AC controller including the first control unit that need power supply;

[0015] The first control unit is in communication connection with the DC controller, and the first control unit switches the working mode according to the interaction result with the DC controller.

[0016] In an optional embodiment of the present application, the AC controller further includes a pre-driving circuit and an inverter circuit;

[0017] The input end of the inverter circuit is connected to the output end of the power factor correction circuit, and the output end is connected to the load;

[0018] The input end of the pre-driving circuit is connected to the first control unit, and the output end is connected to the control end of the inverter circuit. The pre-driving circuit is used to convert the control signal of the first control unit into an electrical signal to drive the inverter circuit.

[0019] In an optional embodiment of the present application, the AC controller further includes a filter capacitor and a pre-charge circuit;

[0020] The filter capacitor is coupled to the output end of the power factor correction circuit;

[0021] The pre-charging circuit is connected between the first input interface and the input end of the rectifier circuit, and the pre-charging circuit has a first circuit and a second circuit.

[0022] After the switching circuit completes the AC / DC power switching, the DC power or AC power inputted by the first input interface first charges the filter capacitor via the first circuit, the rectifier circuit, and the power factor correction circuit, until the filter capacitor is charged to reach the start-up voltage of the power chip of the first power circuit, and then the first power circuit works;

[0023] The first control unit controls the conduction of the second circuit to short-circuit the first circuit, and the DC or AC power input by the first input interface is transmitted to the input end of the rectifier circuit through the second circuit, and is rectified and boosted by the rectifier circuit and the power factor correction circuit before being output.

[0024] In an optional embodiment of the present application, the pre-charging circuit includes a first resistor R1, a relay J1 and a pull-down switch tube;

[0025] The first resistor R1 is connected in parallel with the normally open contact of the relay J1 and then connected in series between the input end of the rectifier circuit and the first input interface;

[0026] One end of the coil of the relay J1 is connected to the output end of the first power supply circuit, and the other end is grounded through the pull-down switch tube. The control end of the pull-down switch tube is connected to the first control unit.

[0027] In an optional embodiment of the present application, the pull-down switch tube is an NPN transistor, and the pre-charging circuit also includes a second resistor R2 and a third resistor R3. The collector of the NPN transistor is connected to the output end of the first power supply circuit through the coil of the relay J1, and the base of the NPN transistor is respectively connected to one end of the second resistor R2 and one end of the third resistor R3, the other end of the second resistor R2 is connected to the first control unit, and the other end of the third resistor R3 and the emitter of the NPN transistor are grounded together.

[0028] In an optional embodiment of the present application, the switch circuit includes a first switch, a second switch and a third switch;

[0029] One end of the first switch is used to be connected to the AC power supply, and the other end is connected to the first input interface;

[0030] One end of the second switch is connected to the DC output interface, and the other end is connected to one end of the third switch;

[0031] The other end of the third switch is connected to the first input interface;

[0032] When the first switch is closed, and the second switch and the third switch are opened, the control circuit is in an AC working mode;

[0033] When the first switch is opened, and the second switch and the third switch are closed at the same time, the control circuit is in a DC working mode.

[0034] In an optional embodiment of the present application, the switching states of the first switch, the second switch, and the third switch are complementary.

[0035] In an optional embodiment of the present application, the DC controller includes a wake-up circuit;

[0036] The power supply end of the wake-up circuit is connected to the connection point of the second switch and the third switch;

[0037] The wake-up circuit is used to obtain a power supply voltage from a connection point between the second switch and the third switch to wake up the DC controller, and the DC controller and the AC controller interact to execute the control logic of the DC working mode.

[0038] In an optional embodiment of the present application, the DC controller further includes a second control unit, a switch circuit, a second power supply circuit and a communication circuit;

[0039] One end of the switch circuit is connected to the DC input interface, and the other end is connected to the input end of the second power supply circuit, and the control end of the switch circuit is connected to the wake-up signal output end of the wake-up circuit and the second control unit respectively;

[0040] The output end of the second power supply circuit is connected to the second control unit and the power supply end of the communication circuit respectively;

[0041] The communication circuit is communicatively connected to the second control unit and the DC power supply respectively;

[0042] The wake-up circuit obtains a power supply voltage from the connection point between the second switching switch and the third switching switch to wake up the switching circuit. The second power supply circuit obtains the DC power output by the DC power supply from the DC input interface, and converts it into a second power supply voltage and outputs it to provide a working voltage to the circuits in the DC controller that need power supply, including the second control unit and the communication circuit.

[0043] In an optional embodiment of the present application, in the DC working mode, the second control unit is further used to control the switch circuit to remain in an on state when the output voltage of the DC power supply is lower than a preset threshold.

[0044] In an optional embodiment of the present application, the switch circuit includes a first switch tube and a second switch tube;

[0045] The input end of the first switch tube is connected to the DC input interface, and the output end is connected to the input end of the second power supply circuit;

[0046] The control end of the second switch tube is respectively connected to the wake-up signal output end of the wake-up circuit and the second control unit, the input end is connected to the control end of the first switch tube, and the output end is grounded.

[0047] In an optional embodiment of the present application, the first switch tube includes a PMOS tube; the second switch tube includes an NPN transistor or an NMOS tube.

[0048] In an optional embodiment of the present application, the wake-up circuit includes a voltage stabilizing diode D2, a fourth resistor R4 and a fifth resistor R5;

[0049] The cathode of the Zener diode D2 serves as the power supply end of the wake-up circuit and is connected to the connection point of the second switching switch and the third switching switch. The anode of the Zener diode D2 is respectively connected to one end of the fourth resistor R4 and the control end of the switching circuit. The other end of the fourth resistor R4 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is grounded.

[0050] In an optional embodiment of the present application, the DC controller further includes a third switch tube;

[0051] The control end of the third switch tube is connected between the fourth resistor R4 and the fifth resistor R5, the input end is respectively connected to the output end of the second power supply circuit and the second control unit, and the output end is grounded.

[0052] In an optional embodiment of the present application, the third switch tube includes an NPN transistor or an NMOS tube.

[0053] To achieve the above objectives and other related objectives, the present application provides an electric tool, comprising:

[0054] A tool body, and a workload, a battery pack, an AC plug and a control circuit arranged on the tool body, wherein the AC plug is used to connect to an AC power source;

[0055] The control circuit comprises:

[0056] A DC controller, having a DC input interface and a DC output interface, wherein the DC input interface is connected to the battery pack;

[0057] A switching circuit, the switching circuit is connected to the DC output interface and the AC plug, and the switching circuit is used to switch between AC and DC power supplies;

[0058] An AC controller has a first input interface, which is connected to the output end of the switching circuit. The AC controller is used to rectify and boost the DC or AC input from the first input interface to supply power to the workload, and the voltages of the two are consistent after boosting.

[0059] As described above, the control circuit of the present application includes a DC controller having a DC input interface and a DC output interface, wherein the DC input interface is connected to a DC power supply; a switching switch circuit, wherein the switching switch circuit is connected to the DC output interface and an AC power supply, wherein the switching switch circuit is used to switch between the AC and DC power supplies; and an AC controller having a first input interface, wherein the first input interface is connected to the output end of the switching switch circuit, wherein the AC controller is used to rectify and boost the DC or AC power inputted by the first input interface and then output the same voltage after the boost. By switching and isolating the AC power supply and the DC power supply through the switching switch circuit, the consistency of the output voltage of the control circuit in the DC working mode and the AC working mode can be improved, thereby ensuring the consistency of the output parameters and performance of the electric tool using the control circuit in the DC working mode and the AC working mode.

[0060] In addition, the control circuit and electric tool of the present application also have higher efficiency and lower power loss, and have the advantages of simple operation, convenient use, flexible switching, safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A schematic diagram of the structure of a high-pressure cleaning machine provided in an embodiment of the present application;

[0062] Figure 2 A circuit diagram of a control circuit provided in an embodiment of the present application;

[0063] Figure 3Shown is a circuit module diagram of an AC controller provided by an embodiment of the present application;

[0064] Figure 4 Shown is a circuit connection diagram of an AC controller and a motor provided in an embodiment of the present application;

[0065] Figure 5 Shown is a circuit connection diagram of a DC controller and a battery pack provided in one embodiment of the present application. DETAILED DESCRIPTION

[0066] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0067] 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 in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0068] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0069] like Figure 1 As shown, the present application provides a high-pressure cleaning machine, which includes a lower bracket assembly 10, a power assembly 20 fixed to the lower bracket assembly 10, an upper bracket assembly 30 extending upward from the lower bracket assembly 10, and a cleaning assembly 40 connected to the upper bracket assembly 30.

[0070] Among them, the lower bracket assembly 10 can serve as the installation base of the power assembly 20 and also as a support for pushing the high-pressure cleaning machine to move. The upper bracket assembly 30 can provide a movable towing handrail for the entire high-pressure cleaning machine and also provide an installation position for various accessories of the cleaning machine.

[0071] The power assembly 20 includes a housing assembly 21, a motor pump assembly 22, a battery pack assembly and a drive assembly. The power assembly 20 can not only provide power and efficient and powerful cleaning performance for the high-pressure cleaner, but also provide a water cooling and heat dissipation solution for the motor pump assembly 22 and the drive assembly, and can also provide a strong power supply guarantee for the motor pump assembly 22. The battery pack assembly is housed in the housing assembly 21. The battery pack assembly can be composed of one or more battery packs. Multiple battery packs can be connected in series and / or in parallel to power the motor pump assembly. An AC plug is provided on the housing assembly 21 for connecting an external AC power supply. The drive assembly is used to use an external AC power supply or a battery pack assembly as a power supply to drive and ensure the operation of the motor pump assembly as a workload.

[0072] The cleaning component 40 is connected to the water outlet of the motor pump component 22, and the motor pump component 22 outputs an external water source to the nozzle of the cleaning component 40 to perform various cleaning tasks.

[0073] like Figure 2-4 As shown, the present application also provides a control circuit for a high-pressure cleaner, which can realize the mutual switching and isolation of AC power and DC power by switching the switch circuit. In a place where AC power can be connected, the high-pressure cleaner can work in AC working mode. When there is no AC power, the battery pack 23 can be used as a DC power supply. At this time, the power tool can work in DC working mode and can ensure that the output working parameters and performance have high consistency in both working modes. It should be noted that the control circuit of the present application can also be applied to other AC and DC universal electric drills, electric screwdrivers, electric sanders, electric saws and other other electric tools.

[0074] In an embodiment of the present application, the DC power supply may be a battery pack 23 suitable for an electric tool, such as a lithium battery pack, a lithium iron phosphate battery pack, etc., and the AC power supply may be AC ​​mains power, or AC power connected through other charging piles or adapter devices.

[0075] like Figure 2-4 As shown, the control circuit includes a switching circuit 60 , an AC controller 50 and a DC controller 70 .

[0076] Among them, the DC controller 70 has a DC input interface and a DC output interface DC+, DC-. The DC input interface is connected to the DC power supply; the switching switch circuit 60 is connected to the DC output interface DC+, DC- and the AC power supply, and the switching switch circuit 60 is used to switch the AC and DC power supplies; the AC controller has a first input interface L, N, and the first input interface L, N is connected to the output end of the switching switch circuit 60. The AC controller 50 is used to rectify and boost the DC or AC input from the first input interface L, N and then output it, and the voltages of the two are consistent after boosting.

[0077] The control circuit can improve the consistency of the output voltage of the control circuit in the DC working mode and the AC working mode, thereby ensuring the consistency of the output parameters and performance of the electric tool using the control circuit in the DC working mode and the AC working mode.

[0078] The control circuit of the present application will be described in detail below with reference to the accompanying drawings.

[0079] like Figure 2-5 As shown, the switching switch circuit 60 is used to switch and isolate the AC power supply and the DC power supply, so that the power tool has two working modes: the AC working mode and the DC working mode. The switching switch circuit 60 may include a first switching switch K1, a second switching switch K2 and a third switching switch K3, and each switching switch may be an electric switch, a relay, a solid-state switch, or other conventional devices that can be configured to open and close an electrical connection.

[0080] One end of the first switch K1 is used to connect to the AC power supply, and the other end is connected to the first input interface L, N. One end of the second switch K2 is connected to the DC output interface DC+, and the other end is connected to one end of the third switch K3. The other end of the third switch K3 is connected to the first input interface L, N. The connection point A between the second switch K2 and the third switch K3 is connected to the power supply end of the wake-up circuit of the DC controller 70; the DC input interface of the DC controller 70 is used to connect to the DC power supply. When the first switch K1 is closed, and the second switch K2 and the third switch K3 are disconnected, the control circuit is in the AC working mode; when the first switch K1 is disconnected, and the second switch K2 and the third switch K3 are closed at the same time, the control circuit is in the DC working mode.

[0081] The switch states of the first switch K1, the second switch K2 and the third switch K3 are complementary. That is, when the first switch K1 is closed, the second switch K2 and the third switch K3 are open, and vice versa, when the first switch K1 is open, the second switch K2 and the third switch K3 are closed. This design can ensure that the control circuit can only work in the AC working mode or the DC working mode, and can also achieve the purpose of AC / DC isolation.

[0082] Among them, in the AC working mode: the first switching switch K1 is closed, the second switching switch K2 and the third switching switch K3 are disconnected at the same time, the AC power output by the AC power supply is transmitted to the first input interface L, N of the AC controller 50 through the first switching switch K1, the AC controller 50 rectifies the AC power and boosts it into DC power and then outputs it to the load 90, and the AC controller 50 executes the AC mode working logic.

[0083] In the DC working mode, the second switch K2 and the third switch K3 are closed at the same time, and when the first switch K1 is disconnected, the DC power output by the DC power supply is transmitted to the first input interface L, N of the AC controller 50 through the DC input interface, the DC output interface DC+, DC-, the second switch K2 and the third switch K3 in sequence, and the AC controller 50 rectifies and boosts the DC power to output it to the load 90. The wake-up circuit obtains the supply voltage from the connection point A of the second switch K2 and the third switch K3 to wake up the DC controller 70, and the DC controller 70 executes the control logic of the DC working mode by interacting with the AC controller 50; wherein, the voltage after rectification and boosting by the AC controller 50 in the DC working mode is consistent with that in the AC working mode, and due to the consistency of the output voltage in the AC and DC working modes, the consistency of the output parameters and performance of the electric tool using the control circuit in the DC working mode and the AC working mode can be ensured.

[0084] By utilizing the basic characteristics that the second switching switch K2 and the third switching switch K3 are conductive when closed and isolated when disconnected, the power supply end of the wake-up circuit is connected to the connection point A of the second switching switch K2 and the third switching switch K3. The power tool will only work under a DC power supply, that is, when the second switching switch K2 and the third switching switch K3 are closed at the same time, the connection point A will be triggered to work.

[0085] Specifically, when the power tool is working under AC power, the live wire (L line) in the AC line is energized, the first switching switch K1 is closed, and the second switching switch K2 and the third switching switch K3 are disconnected. Since the third switching switch K3 is in the disconnected state, the live wire voltage is isolated to ensure that the connection point A is not triggered by mistake.

[0086] When the power tool is working under AC power, if the battery pack 23 is also connected to the circuit, the live wire and the DC controller 70 are both energized. At this time, the first switching switch K1 is closed, the second switching switch K2 and the third switching switch K3 are disconnected, and the DC output interface DC+ of the DC controller 70 is isolated by the second switching switch K2, and the L live wire of the AC line is isolated by the third switching switch K3, ensuring that the connection point A is not triggered by mistake.

[0087] When the power tool is working under a DC power supply, the first switching switch K1 is disconnected, and the second switching switch K2 and the third switching switch K3 are closed at the same time. The DC power output by the DC power supply is output from the DC output interface DC+ of the DC controller 70, and flows out through the second switching switch K2, the connection point A, and the third switching switch K3. That is to say, only when the second switching switch K2 and the third switching switch K3 are closed at the same time, or only in the DC working mode, voltage flows through the connection point A. At this time, the connection point A supplies power to the wake-up circuit, wakes up the second switch tube 74, and enables the circuit of the DC controller 70 to operate normally.

[0088] When the power tool is not working or shut down, the battery pack 23 is always connected to the circuit. At this time, the power tool cannot be accidentally triggered or started, and the battery pack 23 cannot be discharged to death. Only when the second switch K2 and the third switch K3 are closed at the same time, the connection point A can be triggered to work.

[0089] Based on the above analysis, it can be known that the switching switch circuit 60 may also have other design forms, but it needs to meet the above requirements, that is, it can realize the switching and isolation of AC and DC power supplies, and at the same time, it is also necessary to be able to supply power to the wake-up circuit of the DC controller 70 only when switching to DC power supply, and not supply power to the wake-up circuit of the DC controller 70 in other cases.

[0090] See also Figure 3 and 4 As shown, in the embodiment of the present application, the AC controller 50 may also be referred to as an AC control board, which may include a rectifier circuit 57 , a power factor correction (PFC) circuit 51 , a first power supply circuit 52 and a first control unit 53 .

[0091] The rectifier circuit 57 is a rectifier bridge circuit composed of four rectifier diodes, and its input end is connected to the first input interface L, N of the AC controller 50. The rectifier circuit 57 is used to rectify the DC or AC inputted by the first input interface L, N of the AC controller 50. It can be understood that the rectifier circuit 57 can also be a rectifier bridge circuit composed of a MOS tube with a body diode, or other circuits with an uncontrolled rectification function.

[0092] The input end of the power factor correction circuit 51 (PFC circuit for short) is connected to the output end of the rectifier circuit 57, and the power factor correction circuit 51 is used to boost the rectified DC or AC power and output it to the load 90. The PFC circuit can be a boost type PFC circuit, a buck-boost type PFC circuit, a forward type PFC circuit, and a flyback type PFC circuit.

[0093] The first power supply circuit 52 is a DC / DC circuit, whose input end is connected to the output end of the power factor correction circuit 51. The first power supply circuit 52 is used to convert the output voltage of the power factor correction circuit 51 into a first power supply voltage to provide a working voltage to the circuits that need power in the AC controller 50, including the first control unit 53; the first power supply voltage can be set according to the working voltage of each circuit that needs power in the AC controller 50, for example, it can be 15V and 5V.

[0094] The first control unit 53 is in communication connection with the DC controller 70 . The first control unit 53 is used to interact with the DC controller 70 in the DC working mode, and switch the working mode and execute the control logic according to the interaction result.

[0095] See also Figure 3 As shown, the AC controller 50 also includes a pre-driving circuit 54 and an inverter circuit 55. The input end of the inverter circuit 55 is connected to the output end of the power factor correction circuit 51, and the output end is connected to the load 90; the input end of the pre-driving circuit 54 is connected to the first control unit 53, and the output end is connected to the control end of the inverter circuit 55. The pre-driving circuit 54 converts the control signal of the first control unit 53 into an electrical signal for driving the inverter circuit 55. The inverter circuit 55 can convert the output voltage of the power factor correction circuit 51 into an AC power of the required frequency and voltage according to the electrical signal of the pre-driving circuit 54 to drive the load 90 to work. As an example, the conversion circuit is a three-phase inverter bridge, and the load 90 is a three-phase motor.

[0096] See also Figure 3 and 4 As shown, the AC controller 50 further includes a filter capacitor C1 and a pre-charge circuit 56; the filter capacitor C1 is coupled to the output end of the power factor correction circuit 51; the pre-charge circuit 56 is connected between the first input interface N of the AC controller 50 and one input end of the rectifier circuit 57, and the pre-charge circuit 56 has a first line and a second line. It can be understood that in other embodiments, the pre-charge circuit 56 can also be connected between the first input interface L of the AC controller 50 and another input end of the rectifier circuit 57.

[0097] After the switching circuit 60 completes the AC / DC power switching, the DC or AC input from the first input interface L, N first charges the filter capacitor C1 via the first circuit, the rectifier circuit 57, and the power factor correction circuit 51, until the filter capacitor C1 is charged to reach the start-up voltage of the power chip of the first power circuit 52, the first power circuit 52 works to supply power to the first control unit 53, so that the first control unit 53 starts working; then the first control unit 53 controls the second circuit to be turned on to short-circuit the first circuit, and the DC or AC input from the first input interface L, N is transmitted to the input end of the rectifier circuit 57 via the second circuit, and is rectified and boosted by the rectifier circuit 57 and the power factor correction circuit 51 before being output to the load 90.

[0098] See also Figure 4As shown, in a specific embodiment, the pre-charging circuit 56 can be composed of a first resistor R1, a relay J1 and a pull-down switch tube. The first resistor R1 (as a first circuit) is connected in parallel with the normally open contact of the relay J1 (as a second circuit) and then connected in series between the input end of the rectifier circuit 57 and the first input interface N; one end of the coil of the relay J1 is connected to the output end of the first power circuit 52, and the other end is grounded through the pull-down switch tube. The control end of the pull-down switch tube is connected to the first control unit 53. After the first control unit 53 is powered on, the pull-down switch tube is controlled to be turned on. The first power supply voltage output by the first power circuit 52 is connected to the ground through the coil of the relay J1 to form a power supply loop, and the coil of the relay J1 is powered, generating an electromagnetic field to attract the normally open contact of the relay J1 to close. After the normally open contact of the relay J1 is closed, the first resistor R1 is short-circuited, so that the first resistor R1 does not continue to work. Among them, the pull-down switch tube is an NPN transistor Q1, and of course, the pull-down switch tube can also be an NMOS tube.

[0099] Taking the pull-down switch tube as an NPN transistor as an example, the pre-charging circuit 56 is also equipped with a second resistor R2 and a third resistor R3 as current limiting bias resistors. The collector of the NPN transistor is connected to the output end of the first power supply circuit 52 through the coil of the relay J1, and the base of the NPN transistor is respectively connected to one end of the second resistor R2 and one end of the third resistor R3, the other end of the second resistor R2 is connected to the first control unit 53, and the other end of the third resistor R3 and the emitter of the NPN transistor are grounded together.

[0100] See also Figure 5 As shown, in the embodiment of the present application, the DC controller 70 includes a wake-up circuit, the power supply end of the wake-up circuit is connected to the connection point A of the second switch K2 and the third switch K3; the wake-up circuit is used to obtain the power supply voltage from the connection point A of the second switch K2 and the third switch K3 to wake up the DC controller 70, and the DC controller 70 and the AC controller 50 interact to execute the control logic of the DC working mode.

[0101] See also Figure 5 As shown, in the embodiment of the present application, the DC controller 70 further includes a second control unit 71, a switch circuit, a second power supply circuit 75 and communication circuits 72a, 72b. One end of the switch circuit is connected to the DC input interface of the DC controller 70, and the other end is connected to the input end of the second power supply circuit 75. The control end of the switch circuit is respectively connected to the wake-up signal output end of the wake-up circuit and the second control unit 71; the second power supply circuit 75 is a DC / DC circuit, and its output end is respectively connected to the second control unit 71 and the power supply end of the communication circuits 72a, 72b; the communication circuits 72a, 72b are respectively connected to the second control unit 71 and the DC power supply to determine the DC power supply status information.

[0102] In the DC working mode, the wake-up circuit obtains the power supply voltage from the connection point A of the second switching switch K2 and the third switching switch K3 to turn on the wake-up switch circuit, and the second power supply circuit 75 obtains the DC power output by the DC power supply from the DC input interface of the DC controller 70, and converts it into a second power supply voltage and outputs it to provide working voltage to the circuits that need power supply in the DC controller 70, including the second control unit 71, the communication circuits 72a, and 72b. The second power supply voltage can be set according to the working voltage of each circuit that needs power supply in the AC controller 50, for example, it can be 15V and 5V.

[0103] See also Figure 5 As shown, in the embodiment of the present application, the switch circuit includes a first switch tube 73, a second switch tube 74 and related circuits; the input end of the first switch tube 73 is connected to the DC input interface of the DC controller 70, and the output end is connected to the input end of the second power supply circuit 75; the control end of the second switch tube 74 is respectively connected to the wake-up signal output end of the wake-up circuit and the second control unit 71, the input end is connected to the control end of the first switch tube 73, and the output end is grounded. Among them, the first switch tube 73 can be a PMOS tube; the second switch tube 74 can be an NPN transistor or an NMOS tube, and the second switch tube 74 can be controlled to be turned on by the wake-up signal of the wake-up circuit, so as to pull the voltage of the control end of the first switch tube 73 down to the ground, and the first switch tube 73 is turned on, and the DC power output by the DC power supply will supply power to the second power supply circuit 75 through the diode D1 and the first switch tube 73, so that the second power supply circuit 75 outputs the second power supply voltage.

[0104] The wake-up circuit includes a Zener diode D2, a fourth resistor R4 and a fifth resistor R5; the cathode of the Zener diode D2 serves as the power supply end of the wake-up circuit and is connected to the connection point A of the second switching switch K2 and the third switching switch K3; the anode of the Zener diode D2 is respectively connected to one end of the fourth resistor R4 and the control end of the switch circuit (that is, the control end of the second switch tube 74); the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5; and the other end of the fifth resistor R5 is grounded.

[0105] It should be noted that, in this embodiment, the gate of the second switch tube 74 is connected to the second control unit 71. When the output voltage of the DC power supply is lower than the preset threshold and the wake-up circuit cannot provide the control voltage required to turn on the gate of the second switch tube 74, the second control unit 71 controls the switch circuit to remain in the on state, thereby ensuring that when the output voltage of the DC power supply is lower than the preset threshold, the power tool can still operate in the DC working mode.

[0106] See also Figure 3As shown, in the embodiment of the present application, the DC controller 70 further includes a third switch tube 76; the control end of the third switch tube 76 is connected between the fourth resistor R4 and the fifth resistor R5, the input end is respectively connected to the output end of the second power supply circuit 75 and the second control unit 71, the output end is grounded, and the third switch tube 76 includes an NPN transistor or an NMOS tube. The third switch tube 76 can output a level signal to the second control unit 71 when the second switching switch K2 and the third switching switch K3 are closed, and the second switch tube 74 and the first switch tube 73 are turned on, and the second power supply circuit 75 outputs the second supply voltage, and the second control unit 71 determines the operating state of the DC controller 70 according to the level signal.

[0107] The following will be combined Figure 2-4 , taking a 120V DC power supply and a 120V AC power supply as an example, the 120V DC power supply is composed of two 60V battery packs 23 connected in series.

[0108] AC working mode: insert the AC plug 80 into the 120V AC power supply, and then close the first switch K1. At this time, the second switch K2 and the third switch K3 are disconnected, and the power tool works in the AC working mode. The 120V AC power flows to the first input interface L, N of the AC controller 50 through the first switch K1, and charges the filter capacitor C1 through the fuse F1, the first resistor R1, the rectifier circuit 57, and the power factor correction circuit 51. When the filter capacitor C1 is charged to reach the power chip start-up voltage of the first power circuit 52, the first power circuit 52 outputs 15V and 5V to power the first control unit 53 and other related circuits. The first control unit 53 turns on the NPN transistor Q1 through the second resistor R2 and the third resistor R3 to conduct to the ground. At this time, 15V is connected to the ground through the coil inside the relay J1 to form a power supply loop, and the coil of the relay J1 is powered, generating an electromagnetic field to attract the relay to close. After the relay J1 is attracted, the first R1 resistor is short-circuited, so that the first R1 no longer works continuously, and the 120V The DC voltage of AC after passing through the rectifier circuit 57 is 1.414 times the AC voltage, that is, =120*1.414=169.68V, and then it is boosted by the power factor correction circuit 51. The specific boost value can be set according to the actual circuit needs. For example, it can be boosted to 220V or more to meet the design requirements.

[0109] DC working mode: After the battery pack 23 is inserted into the cavity, the second switch K2 and the third switch K3 are closed. At this time, the first switch K1 is disconnected, and the power tool works in the DC working mode. At this time, the 120V DC power output by the battery pack 23 in the DC controller 70 is output from the DC output interface DC+ and DC- through the second switch K2 and the third switch K3 to the first input interface L and N of the AC controller 50. At this time, the connection point A between the second switch K2 and the third switch K3 obtains voltage to power the wake-up circuit composed of the voltage-stabilizing diode D2, the fourth resistor R4, and the fifth resistor R5. First, the second switch tube 74 is triggered to turn on, and then the first switch tube 73 is turned on. The 120V DC power output by the battery pack 23 powers the second power supply circuit 75 through the diode D1 and the first switch tube 73, so that the second power supply circuit 75 outputs 15V and 5V, which are supplied to the second control unit 71 and the communication circuit The communication circuit 72a and the battery pack 231 perform a communication handshake protocol, and the communication circuit 72b performs a communication handshake protocol with the battery pack 232. The communication circuit 72a and the communication circuit 72b then exchange information with the second control unit 71 respectively. After confirming that the communication is normal, the second control unit 71 sends data to the first control unit 53. When the first control unit 53 receives the data from the second control unit 71, the first control unit 53 can use whether the data sent by the second control unit 71 is received as a judgment condition. When the communication data sent by the second control unit 71 is received, it is defined as a DC working mode, otherwise it is an AC working mode. In this way, the first control unit 53 identifies different working modes and manages them separately. When in the DC working mode, the first control unit 53 can also perform different protections according to different codes sent by the second control unit 71, such as: over-temperature protection, under-voltage protection, over-current protection, etc. of the battery pack 23.

[0110] At the same time, when the DC power output by the battery pack 23 is sent to the first input interface L, N of the AC controller 50, the DC power is charged to the filter capacitor C1 through the fuse F1, the first resistor R1, the rectifier circuit 57, and the power factor correction circuit 51. When the filter capacitor C1 is charged to reach the power chip start-up voltage of the first power circuit 52, the first power circuit 52 outputs 15V and 5V to power the first control unit 53 and other related circuits. The first control unit 53 turns on the NPN transistor Q1 through the second resistor R2 and the third resistor R3 to conduct The 15V is connected to the ground through the coil inside the relay J1 to form a power supply loop, supplying power to the coil inside the relay J1, generating an electromagnetic field to attract the relay J1 to close, and the relay J1 is attracted to short-circuit the first resistor R1, so that the first resistor R1 is no longer working continuously. At this time, the 120V DC power is still 120V DC after passing through the rectifier circuit 57 (ignoring the voltage drop during the rectification process), and then it is boosted by the PFC circuit. The specific boost value can be set according to the actual circuit needs, for example, boosted to 220V or more. Therefore, when the boost value is set to 220V, regardless of whether the 120V AC power input or the 120V DC power input, the bus voltage after boosting by the power factor correction circuit 51 is 220V DC.

[0111] In summary, the control circuit and electric tool disclosed in the present application can realize the mutual switching and isolation of AC power supply and DC power supply by switching the switch circuit, which can improve the consistency of the output voltage of the control circuit in DC working mode and AC working mode, thereby ensuring the consistency of the output parameters and performance of the electric tool using the control circuit in DC working mode and AC working mode. In addition, the control circuit and electric tool of the present application also have higher efficiency and lower power loss, and have the advantages of simple operation, easy use, flexible switching, safety and reliability. Therefore, the present application effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0112] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A control circuit, characterized in that: include: A DC controller having a DC input interface and a DC output interface, wherein the DC input interface is connected to a DC power supply; A switching circuit, the switching circuit is connected to the DC output interface and the AC power supply, and the switching circuit is used to switch the AC and DC power supplies; The AC controller has a first input interface, which is connected to the output end of the switching circuit. The AC controller is used to rectify and boost the DC or AC input from the first input interface and then output it. The voltages of the two are consistent after boosting.

2. The control circuit according to claim 1, characterized in that: The AC controller includes a rectifier circuit, a power factor correction circuit, a first power supply circuit and a first control unit; The input end of the rectifier circuit is connected to the first input interface, and the rectifier circuit is used to rectify the direct current or alternating current input by the first input interface; The input end of the power factor correction circuit is connected to the output end of the rectifier circuit, and the power factor correction circuit is used to boost the rectified direct current or alternating current and then output it; The input end of the first power supply circuit is connected to the output end of the power factor correction circuit, and the first power supply circuit is used to convert the output voltage of the power factor correction circuit into a first power supply voltage to provide a working voltage to the circuits in the AC controller including the first control unit that need power supply; The first control unit is in communication connection with the DC controller, and the first control unit switches the working mode according to the interaction result with the DC controller.

3. The control circuit according to claim 2, characterized in that: The AC controller also includes a pre-driving circuit and an inverter circuit; The input end of the inverter circuit is connected to the output end of the power factor correction circuit, and the output end is connected to the load; The input end of the pre-driving circuit is connected to the first control unit, and the output end is connected to the control end of the inverter circuit. The pre-driving circuit is used to convert the control signal of the first control unit into an electrical signal to drive the inverter circuit.

4. The control circuit according to claim 2, characterized in that: The AC controller also includes a filter capacitor and a pre-charge circuit; The filter capacitor is coupled to the output end of the power factor correction circuit; The pre-charging circuit is connected between the first input interface and the input end of the rectifier circuit, and the pre-charging circuit has a first circuit and a second circuit. After the switching circuit completes the AC / DC power switching, the DC power or AC power inputted by the first input interface first charges the filter capacitor via the first circuit, the rectifier circuit, and the power factor correction circuit, until the filter capacitor is charged to reach the start-up voltage of the power chip of the first power circuit, and then the first power circuit works; The first control unit controls the conduction of the second circuit to short-circuit the first circuit, and the DC or AC power input by the first input interface is transmitted to the input end of the rectifier circuit through the second circuit, and is rectified and boosted by the rectifier circuit and the power factor correction circuit before being output.

5. The control circuit according to claim 4, characterized in that: The pre-charging circuit includes a first resistor R1, a relay J1 and a pull-down switch tube; The first resistor R1 is connected in parallel with the normally open contact of the relay J1 and then connected in series between the input end of the rectifier circuit and the first input interface; One end of the coil of the relay J1 is connected to the output end of the first power supply circuit, and the other end is grounded through the pull-down switch tube. The control end of the pull-down switch tube is connected to the first control unit.

6. The control circuit according to claim 5, characterized in that: The pull-down switch tube is an NPN transistor, and the pre-charging circuit also includes a second resistor R2 and a third resistor R3. The collector of the NPN transistor is connected to the output end of the first power supply circuit through the coil of the relay J1, and the base of the NPN transistor is respectively connected to one end of the second resistor R2 and one end of the third resistor R3, the other end of the second resistor R2 is connected to the first control unit, and the other end of the third resistor R3 and the emitter of the NPN transistor are grounded together.

7. The control circuit according to claim 1, characterized in that: The switching circuit includes a first switching switch, a second switching switch and a third switching switch; One end of the first switch is used to be connected to the AC power supply, and the other end is connected to the first input interface; One end of the second switch is connected to the DC output interface, and the other end is connected to one end of the third switch; The other end of the third switch is connected to the first input interface; When the first switch is closed, and the second switch and the third switch are opened, the control circuit is in an AC working mode; When the first switch is opened, and the second switch and the third switch are closed at the same time, the control circuit is in a DC working mode.

8. The control circuit according to claim 7, characterized in that: The switching states of the first switch, the second switch and the third switch are complementary.

9. The control circuit according to claim 7, characterized in that: The DC controller includes a wake-up circuit; The power supply end of the wake-up circuit is connected to the connection point of the second switch and the third switch; The wake-up circuit is used to obtain a power supply voltage from a connection point between the second switch and the third switch to wake up the DC controller, and the DC controller and the AC controller interact to execute the control logic of the DC working mode.

10. The control circuit according to claim 9, characterized in that: The DC controller also includes a second control unit, a switch circuit, a second power supply circuit and a communication circuit; One end of the switch circuit is connected to the DC input interface, and the other end is connected to the input end of the second power supply circuit, and the control end of the switch circuit is connected to the wake-up signal output end of the wake-up circuit and the second control unit respectively; The output end of the second power supply circuit is connected to the second control unit and the power supply end of the communication circuit respectively; The communication circuit is communicatively connected to the second control unit and the DC power supply respectively; The wake-up circuit obtains a power supply voltage from the connection point between the second switching switch and the third switching switch to wake up the switching circuit. The second power supply circuit obtains the DC power output by the DC power supply from the DC input interface, and converts it into a second power supply voltage and outputs it to provide a working voltage to the circuits in the DC controller that need power supply, including the second control unit and the communication circuit.

11. The control circuit according to claim 10, characterized in that: In the DC working mode, the second control unit is further used to control the switch circuit to remain in the on state when the output voltage of the DC power supply is lower than a preset threshold.

12. The control circuit according to claim 10 or 11, characterized in that: The switch circuit includes a first switch tube and a second switch tube; The input end of the first switch tube is connected to the DC input interface, and the output end is connected to the input end of the second power supply circuit; The control end of the second switch tube is respectively connected to the wake-up signal output end of the wake-up circuit and the second control unit, the input end is connected to the control end of the first switch tube, and the output end is grounded.

13. The control circuit according to claim 12, characterized in that: The first switch tube includes a PMOS tube; the second switch tube includes an NPN transistor or an NMOS tube.

14. The control circuit according to claim 10, characterized in that: The wake-up circuit includes a voltage stabilizing diode D2, a fourth resistor R4 and a fifth resistor R5; The cathode of the Zener diode D2 serves as the power supply end of the wake-up circuit and is connected to the connection point of the second switching switch and the third switching switch. The anode of the Zener diode D2 is respectively connected to one end of the fourth resistor R4 and the control end of the switching circuit. The other end of the fourth resistor R4 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is grounded.

15. The control circuit according to claim 14, characterized in that: The DC controller also includes a third switch tube; The control end of the third switch tube is connected between the fourth resistor R4 and the fifth resistor R5, the input end is respectively connected to the output end of the second power supply circuit and the second control unit, and the output end is grounded.

16. The control circuit according to claim 15, characterized in that: The third switch tube includes an NPN transistor or an NMOS transistor.

17. An electric tool, characterized in that: include: A tool body, and a workload, a battery pack, an AC plug and a control circuit arranged on the tool body, wherein the AC plug is used to connect to an AC power source; The control circuit comprises: A DC controller, having a DC input interface and a DC output interface, wherein the DC input interface is connected to the battery pack; A switching circuit, the switching circuit is connected to the DC output interface and the AC plug, and the switching circuit is used to switch between AC and DC power supplies; An AC controller has a first input interface, which is connected to the output end of the switching circuit. The AC controller is used to rectify and boost the DC or AC input from the first input interface to supply power to the workload, and the voltages of the two are consistent after boosting.

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