Low-power-consumption on-off circuit for electric tool

Abstract

The invention relates to the technical field of electric appliance on-off control, and provides a low-power-consumption on-off circuit for an electric tool, a first trigger module is connected in series between a slide switch and a third switch module, and normal operation of the circuit is guaranteed while quick start is realized through sequential alternate control of hardware start-up and software start-up; after the preset time period, a closing signal is output to control the third switch module to stop working, so that the starting circuit corresponding to the first switch module can stop working through the third switch module even if the starting circuit is connected with the battery through the sliding switch all the time after being electrified; the power-on loop of the starting circuit only needs extremely low quiescent current, so that the power-on energy consumption of the circuit is greatly reduced, the endurance time of the battery pack is effectively prolonged, and the scrapping risk of the battery pack caused by forgetting to turn off the sliding switch is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of electrical appliance switch control, and in particular to a low-power switch circuit for electric tools. Background Art

[0002] Most of the one-button power on and off circuits of power tools on the market use self-pop-up touch switches or sliding switches as braking elements, which can achieve low power consumption after shutting down.

[0003] In normal usage scenarios, if the power tool (for example, Bosch 12V lithium-ion grinder) uses a sliding switch as a braking element, low power consumption can be achieved if the user is in a normal shutdown state; however, when the power tool is in low battery and power-off state, if the user forgets to slide the sliding switch to the off state, even if the power output of the power load is disconnected through the MCU, the battery pack still outputs static current to the load power supply circuit to maintain the standby state, which will cause the circuit to be in a continuous power consumption state.

[0004] In this case, if the user does not remove the battery pack in time, the battery pack will be exhausted after a while. If the user does not remove the battery pack for a long time, more than 3 months, there may be a risk of the battery pack being scrapped. Summary of the invention

[0005] The present invention provides a low-power switch circuit for an electric tool, which solves the technical problem that the existing switch circuit is limited to the physical control of a brake switch and will continue to consume the power of a battery pack if the power is not cut off in time, thereby causing the battery pack to be scrapped.

[0006] In order to solve the above technical problems, the present invention provides a low-power switch circuit for an electric tool, comprising:

[0007] A first switch module connected in series to the main power supply circuit;

[0008] A second switch module and a third switch module connected to the control end of the first switch module;

[0009] A first trigger module and a second trigger module connected to the slide switch;

[0010] A main controller connected to the second switch module, the third switch module, and the second trigger module;

[0011] The main controller collects the state feedback of the sliding switch or the state change of the third switch module through the second trigger module; and then drives the first switch module to turn on or off the main power supply circuit by controlling the state change of the second switch module;

[0012] After the first trigger module is connected to the battery pack power supply through the sliding switch, the first trigger module outputs a start signal to control the third switch module to drive the first switch module to turn on the main power supply circuit; and after a preset time period, the first trigger module outputs a shutdown signal to control the third switch module to stop working, and the first trigger module enters a low-power standby state.

[0013] In this basic solution, the first trigger module is connected in series between the sliding switch and the third switch module, and the control is replaced in sequence by hardware startup and software startup, so as to achieve fast startup while ensuring the normal operation of the circuit; and by outputting a shutdown signal to control the third switch module to stop working after a preset time period, even if the startup circuit corresponding to the first switch module is always connected to the battery through the sliding switch after power-on, it can be stopped by the third switch module, so that the power-on circuit of the startup circuit only needs an extremely low static current, thereby greatly reducing the startup energy consumption of the circuit, effectively improving the battery life of the battery pack, and avoiding the risk of scrapping the battery pack due to forgetting to turn off the sliding switch.

[0014] In a further embodiment, the sliding switch includes a first static contact, a second static contact and a moving contact, one end of the moving contact is electrically connected to the battery pack, and the other end is connected to the first static contact or the second static contact; the first static contact is connected to the input end of the first trigger module, and the second static contact is connected to the input end of the second trigger module.

[0015] In a further embodiment, the first trigger module includes a NAND gate U1A, a NAND gate U1B, a resistor R1, a capacitor C1 and a capacitor C2; one end of the resistor R1 is connected to the first static contact of the sliding switch, and the other end is connected to the input end of the NAND gate U1A; the input end of the NAND gate U1B is connected to the output end of the NAND gate U1A, and the output end is connected to the control end of the third switch module; one end of the capacitor C1 is connected to the other end of the resistor R1, and the other end is grounded; one end of the capacitor C2 is connected to the ADD pin of the NAND gate U1A, and the other end is grounded;

[0016] When the moving contact of the sliding switch is connected to the first static contact, the battery pack charges the capacitor C1 through the resistor R1. Since the voltage across the capacitor C1 will not change suddenly, at this time, the input end of the NAND gate U1A inputs a low level, and the output end of the NAND gate U1A outputs a low level to the input end of the NAND gate U1B. The output end of the NAND gate U1B outputs a low level to control the first switch module to drive the first switch module to turn on the main power supply circuit;

[0017] The main controller collects the state change of the third switch module, and then controls the second switch module to replace the third switch module, so as to drive the first switch module to turn on the main power supply circuit;

[0018] When the capacitor C1 is fully charged, the input end of the NAND gate U1A inputs a high level, and the output end of the NAND gate U1A outputs a high level to the input end of the NAND gate U1B, and the output end of the NAND gate U1B outputs a high level to control the first switch module to stop working and enter a low power consumption state.

[0019] This solution is based on a double NAND gate (NAND gate U1A and NAND gate U1B) and a capacitor. The double NAND gate is used to trigger the signal of power access. At the same time, combined with the charge storage capacity of the capacitor, when the moving contact of the sliding switch is connected to the first static contact, the double NAND gate is triggered for quick startup; then, when the capacitor C1 is fully charged, the input signal of the double NAND gate is changed to complete a startup signal conversion; finally, if the user forgets to turn off the sliding switch, the static current of the double NAND gate is maintained at 4uA, which can greatly reduce the energy consumption of the battery pack. Even after the power tool is low on power, it can still last for more than 6 months, avoiding the risk of the battery pack being scrapped.

[0020] In a further embodiment, the second trigger module includes a signal trigger module, and the signal trigger module includes a switch tube Q1A, a resistor R2, a resistor R3, a resistor R4 and a capacitor C3; the first end of the switch tube Q1A is connected to the power supply end through the resistor R2, the second end is grounded, and the control end is connected to the second static contact of the sliding switch through the resistor R3; one end of the capacitor C3 is connected to the second static contact of the sliding switch, and the other end is grounded; one end of the resistor R4 is connected to the control end of the switch tube Q1A, and the other end is connected; the first end of the switch tube Q1A is also connected to the main controller;

[0021] When the moving contact of the sliding switch is connected to the second static contact, the switch tube Q1A is turned on and outputs a shutdown signal to the main controller. The main controller drives the first switch module to disconnect the main power supply circuit by controlling the second switch module to perform physical shutdown and software shutdown.

[0022] This solution connects a signal trigger module with the switch tube Q1A as the core to the second static contact of the sliding switch, and monitors in real time whether the sliding switch slides to the second static contact, thereby realizing real-time, low-power monitoring of the shutdown signal.

[0023] In a further embodiment, the second trigger module further includes a discharge module, the discharge module including a switch tube Q1B, a resistor R5 and a resistor R6; the first end of the switch tube Q1B is connected to one end of the capacitor C2, the second end is grounded, and the control end is connected to the second static contact through the resistor R5; one end of the resistor R6 is connected to the control end of the switch tube Q1B, and the other end is grounded;

[0024] When the moving contact of the slide switch is connected to the second static contact, the switch tube Q1B is turned on, and the electric energy in the capacitor C2 is discharged through the switch tube Q1B to prepare for the next quick start.

[0025] In this solution, a switch tube Q1B is connected to the second static contact of the sliding switch, and the discharge circuit of the capacitor C1 is turned on by the triggering of the shutdown signal of the sliding switch to prepare for a quick start next time.

[0026] In a further implementation scheme, the first switch module includes a switch tube Q2, a resistor R7, a diode D1 and a capacitor C4, the first end of the switch tube Q2 is connected to the rear-end load, the second end is connected to the battery pack, and the control end is connected to the second switch module and the third switch module; the positive electrode of the diode D1 is connected to the control end of the switch tube Q2, and the negative electrode is connected to the second end of the switch tube Q2; the resistor R7 is connected in parallel with the diode D1; one end of the capacitor C4 is connected to the control end of the switch tube Q2, and the other end is grounded.

[0027] In this solution, a first switch module with a switch tube as the core is connected in series in the main circuit. Since the switch tube can complete the conversion between the on and off states in a short time, it helps to reduce the switching loss in the switching power supply.

[0028] In a further embodiment, the second switch module includes a switch tube Q3, a resistor R8, a resistor R9, a resistor R10, a capacitor C5 and a diode D2; the first end of the switch tube Q3 is connected to the control end of the first switch module, the second end is grounded through the resistor R9, and the control end is connected to the output end of the first switch module through the resistor R8; one end of the resistor R10 is connected to the control end of the switch tube Q3, and the other end is grounded; the capacitor C5 is connected in parallel with the resistor R10; the positive electrode of the diode D2 is connected to the main controller, and the negative electrode is connected to the control end of the switch tube Q3;

[0029] The main controller drives the switch tube Q3 to be turned on or off by changing the signal input to the positive electrode of the diode D2, thereby changing the potential of the control end of the first switch module and turning on or off the main power supply circuit.

[0030] In this solution, the control end of the switch tube Q2 is connected to the switch tube Q3 for switch control, which can control the output of large current with small current, and in the cut-off state, the transistor consumes almost no current, thereby reducing the power consumption of the entire circuit.

[0031] In a further embodiment, the third switch tube includes a switch tube Q4, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a diode D3 and a diode D4;

[0032] The first end of the switch tube Q4 is connected to the cathode of the diode D3 and the cathode of the diode D4, the second end is grounded, and the control end is connected to the output end of the first trigger module through the resistor R13;

[0033] The anode of the diode D3 is connected to the control end of the first switch module through the resistor R11; the anode of the diode D4 is connected to the main controller, and is used to feed back the working state of the switch tube Q4 to the main controller;

[0034] The two ends of the resistor R12 are respectively connected to the first end and the control end of the switch tube Q4; one end of the resistor R14 is connected to the battery pack, and the other end is connected to the control end of the switch tube Q4 through the resistor R13;

[0035] After the first trigger module is connected to the battery pack power supply through the sliding switch, the first trigger module outputs a start signal to control the switch tube Q4 to turn on, thereby driving the first switch module to turn on the main power supply circuit; at the same time, the main controller receives a power-on signal through the positive electrode of the diode D4, thereby controlling the second switch module to replace the switch tube Q4 to drive the first switch module to turn on the main power supply circuit.

[0036] This solution sets a third switch module in parallel with the second switch module, uses the switch tube Q4 to quickly start the sliding switch, and then uses the switch tube Q3 to achieve continuous conduction control of the main power supply circuit, converting from hardware control to software control, and can continue to power the system after the sliding switch is turned off, avoiding the situation in the traditional circuit where the power is immediately cut off after the sliding switch, thereby reducing unnecessary circuit restarts and energy consumption. This design achieves lower power consumption by optimizing power management.

[0037] In a further embodiment, the switch tube Q2 is an N-channel MOS tube or a P-channel MOS tube.

[0038] In a further embodiment, the battery pack is a lithium battery or a lead-acid battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a system framework diagram of a low-power on / off circuit for an electric tool provided by an embodiment of the present invention;

[0040] Figure 2 It is a hardware circuit diagram of some modules provided by an embodiment of the present invention;

[0041] Figure 3 It is a hardware circuit diagram of some modules provided by an embodiment of the present invention;

[0042] Figure 4 It is a hardware circuit diagram of some modules provided by an embodiment of the present invention;

[0043] Among them: a first switch module 1, a second switch module 2, a third switch module 3, a sliding switch SW1, a first trigger module 4, a second trigger module 5, a main controller 6, and a battery pack 7. DETAILED DESCRIPTION

[0044] The following specifically illustrates the implementation mode of the present invention in conjunction with the accompanying drawings. The embodiments are provided for illustrative purposes only and cannot be understood as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0045] An embodiment of the present invention provides a low power consumption on / off circuit for an electric tool, such as Figure 1 to Figure 4 As shown, in this embodiment, it includes:

[0046] A first switch module 1 connected in series to the main power supply circuit;

[0047] A second switch module 2 and a third switch module 3 connected to the control end of the first switch module 1;

[0048] A first trigger module 4 and a second trigger module 5 connected to the slide switch SW1;

[0049] A main controller 6 connected to the second switch module 2, the third switch module 3, and the second trigger module 5;

[0050] The main controller 6 collects the state feedback of the sliding switch SW1 through the second trigger module 5, or collects the state change of the third switch module 3; and then drives the first switch module 1 to turn on or off the main power supply circuit by controlling the state change of the second switch module 2;

[0051] After the first trigger module 4 is connected to the power supply of the battery pack 7 through the sliding switch SW1, it outputs a start signal to control the third switch module 3 to drive the first switch module 1 to turn on the main power supply circuit; and after a preset time period, it outputs a shutdown signal to control the third switch module 3 to stop working, and the first trigger module 4 enters a low-power standby state.

[0052] In this embodiment, see Figure 2The sliding switch SW1 includes a first static contact NC, a second static contact ON and a moving contact, one end of the moving contact is electrically connected to the battery pack 7, and the other end is connected to the first static contact NC or the second static contact ON; the first static contact NC is connected to the input end of the first trigger module 4, and the second static contact ON is connected to the input end of the second trigger module 5.

[0053] In this embodiment, the first trigger module 4 includes a NAND gate U1A, a NAND gate U1B, a resistor R1, a capacitor C1 and a capacitor C2; one end of the resistor R1 is connected to the first static contact NC of the slide switch SW1, and the other end is connected to the input end of the NAND gate U1A; the input end of the NAND gate U1B is connected to the output end of the NAND gate U1A, and the output end (such as Figure 2 , Figure 4 The connection point a) is connected to the control end of the third switch module 3; one end of the capacitor C1 is connected to the other end of the resistor R1, and the other end is grounded; one end of the capacitor C2 is connected to the ADD pin of the NAND gate U1A, and the other end is grounded;

[0054] When the moving contact of the sliding switch SW1 is connected to the first static contact NC, the battery pack 7 charges the capacitor C1 through the resistor R1. Since the voltage across the capacitor C1 will not change suddenly, at this time, the input end of the NAND gate U1A inputs a low level, and the output end of the NAND gate U1A outputs a low level to the input end of the NAND gate U1B. The output end of the NAND gate U1B outputs a low level to control the first switch module 1 to drive the first switch module 1 to turn on the main power supply circuit;

[0055] The main controller 6 collects the state change of the third switch module 3, and then controls the second switch module 2 to replace the third switch module 3, driving the first switch module 1 to turn on the main power supply circuit;

[0056] When the capacitor C1 is fully charged, the input end of the NAND gate U1A inputs a high level, and the output end of the NAND gate U1A outputs a high level to the input end of the NAND gate U1B, and the output end of the NAND gate U1B outputs a high level to control the first switch module 1 to stop working and enter a low power consumption state.

[0057] This embodiment takes the double NAND gate (NAND gate U1A and NAND gate U1B) and capacitor as the core, utilizes the double NAND gate to perform the signal trigger of power access, and combines the charge storage capacity of the capacitor at the same time, when the moving contact of the sliding switch SW1 is connected with the first static contact NC, the double NAND gate is triggered to start quickly; then when the capacitor C1 is fully charged, the input signal of the double NAND gate is changed, thereby completing a startup signal conversion; finally, if the user forgets to turn off the sliding switch SW1, since the static current of the double NAND gate is maintained at 4uA, the energy consumption of the battery pack 7 can be greatly reduced, and even after the power tool is low in power, it can still be maintained for more than 6 months, avoiding the risk of the battery pack 7 being scrapped.

[0058] In this embodiment, the second trigger module 5 includes a signal trigger module, which includes a switch tube Q1A, a resistor R2, a resistor R3, a resistor R4 and a capacitor C3; the first end of the switch tube Q1A is connected to the power supply end through the resistor R2, the second end is grounded, and the control end is connected to the second static contact ON of the sliding switch SW1 through the resistor R3; one end of the capacitor C3 is connected to the second static contact ON of the sliding switch SW1, and the other end is grounded; one end of the resistor R4 is connected to the control end of the switch tube Q1A, and the other end is connected; the first end of the switch tube Q1A is also connected to the main controller 6;

[0059] When the moving contact of the sliding switch SW1 is connected to the second static contact ON, the switch tube Q1A is turned on and outputs a shutdown signal to the main controller 6. The main controller 6 drives the first switch module 1 to disconnect the main power supply circuit by controlling the second switch module 2 to perform physical shutdown and software shutdown.

[0060] In this embodiment, a signal trigger module with the switch tube Q1A as the core is connected to the second static contact ON of the sliding switch SW1 to monitor in real time whether the sliding switch SW1 slides to the second static contact ON, thereby realizing real-time and low-power monitoring of the shutdown signal.

[0061] In this embodiment, the second trigger module 5 further includes a discharge module, which includes a switch tube Q1B, a resistor R5 and a resistor R6; a first end of the switch tube Q1B is connected to one end of the capacitor C2, a second end is grounded, and a control end is connected to the second static contact ON through the resistor R5; one end of the resistor R6 is connected to the control end of the switch tube Q1B, and the other end is grounded;

[0062] When the moving contact of the slide switch SW1 is connected to the second static contact ON, the switch tube Q1B is turned on, and the electric energy in the capacitor C2 is discharged through the switch tube Q1B to prepare for the next quick start.

[0063] The switch tube Q1A is an N-channel MOS tube or a P-channel MOS tube; the switch tube Q1B is an N-channel MOS tube or a P-channel MOS tube.

[0064] In this embodiment, a switch tube Q1B is connected to the second static contact ON of the slide switch SW1. The shutdown signal of the slide switch SW1 triggers the discharge circuit of the capacitor C1 to prepare for a quick start next time.

[0065] Among them, the switch tube Q1A and the switch tube Q1B form a composite tube.

[0066] In this embodiment, see Figure 3 The first switch module 1 includes a switch tube Q2, a resistor R7, a diode D1 and a capacitor C4. The first end of the switch tube Q2 is connected to the rear end load (such as Figure 3 The first end is connected to the connection point c) in the figure, the second end is connected to the battery pack 7, and the control end is connected to the second switch module 2 and the third switch module 3; the positive electrode of the diode D1 is connected to the control end of the switch tube Q2, and the negative electrode is connected to the second end of the switch tube Q2; the resistor R7 is connected in parallel with the diode D1; one end of the capacitor C4 is connected to the control end of the switch tube Q2, and the other end is grounded.

[0067] In this embodiment, the switch tube Q2 is an N-channel MOS tube or a P-channel MOS tube.

[0068] In this embodiment, a first switch module 1 with a switch tube as the core is connected in series in the main circuit. Since the switch tube can complete the conversion between the on and off states in a short time, it is helpful to reduce the switching loss in the switching power supply.

[0069] In this embodiment, the second switch module 2 includes a switch tube Q3, a resistor R8, a resistor R9, a resistor R10, a capacitor C5 and a diode D2; the first end of the switch tube Q3 is connected to the control end of the first switch module 1, the second end is grounded through the resistor R9, and the control end is connected to the output end of the first switch module 1 through the resistor R8; one end of the resistor R10 is connected to the control end of the switch tube Q3, and the other end is grounded; the capacitor C5 is connected in parallel with the resistor R10; the positive electrode of the diode D2 is connected to the main controller 6, and the negative electrode is connected to the control end of the switch tube Q3;

[0070] The main controller 6 drives the switch tube Q3 to be turned on or off by changing the signal input to the positive electrode of the diode D2, thereby changing the potential of the control end of the first switch module 1 to turn on or off the main power supply circuit.

[0071] In this embodiment, the switch tube Q3 is an NPN transistor or a PNP transistor.

[0072] In this embodiment, the control end of the switch tube Q2 is connected to the switch tube Q3 for switch control, which can control the output of large current with small current, and in the cut-off state, the transistor consumes almost no current, thereby reducing the power consumption of the entire circuit.

[0073] In this embodiment, see Figure 4 , the third switch tube includes a switch tube Q4, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a diode D3 and a diode D4;

[0074] The first end of the switch tube Q4 is connected to the cathode of the diode D3 and the cathode of the diode D4, the second end is grounded, and the control end is connected to the output end of the first trigger module 4 through the resistor R13;

[0075] The anode of the diode D3 is connected to the control terminal of the first switch module 1 (such as Figure 3 , Figure 4 The anode of the diode D4 is connected to the main controller 6 for feeding back the working state of the switch tube Q4 to the main controller 6;

[0076] The two ends of the resistor R12 are respectively connected to the first end and the control end of the switch tube Q4; one end of the resistor R14 is connected to the battery pack 7, and the other end is connected to the control end of the switch tube Q4 through the resistor R13;

[0077] After the first trigger module 4 is connected to the power supply of the battery pack 7 through the sliding switch SW1, it outputs a start signal to control the switch tube Q4 to turn on, thereby driving the first switch module 1 to turn on the main power supply circuit; at the same time, the main controller 6 receives the power-on signal through the positive electrode of the diode D4, thereby controlling the second switch module 2 to replace the switch tube Q4 to drive the first switch module 1 to turn on the main power supply circuit.

[0078] The diode D3 and the diode D4 are used to prevent backflow and ensure the accuracy of signal triggering.

[0079] In this embodiment, the switch tube Q4 is an NPN transistor or a PNP transistor.

[0080] This embodiment sets a third switch module 3 connected in parallel with the second switch module 2, uses the switch tube Q4 to realize the rapid start of the sliding switch SW1, and then uses the switch tube Q3 to realize the continuous conduction control of the main power supply circuit, converting from hardware control to software control, and can continue to power the system after the sliding switch SW1 is turned off, avoiding the situation in the traditional circuit where the power is cut off immediately after the sliding switch SW1 is turned on, thereby reducing unnecessary circuit restarts and energy consumption. This design achieves lower power consumption by optimizing power management.

[0081] In this embodiment, the battery pack 7 is a lithium battery or a lead-acid battery.

[0082] The main controller 6 is a chip with data processing function, including but not limited to MCU.

[0083] See also Figure 2 Taking the switch tube Q1A as an N-channel MOS tube, the switch tube Q1B as an N-channel MOS tube, the switch tube Q2 as a P-channel MOS tube, the switch tube Q3 as an NPN-type transistor, and the switch tube Q4 as a PNP-type transistor as an example, the switching principle of this embodiment is as follows:

[0084] 1. Startup

[0085] (1) When the moving contact of the sliding switch SW1 is connected to the first static contact NC, the battery pack 7 charges the capacitor C1 through the resistor R1. Since the voltage across the capacitor C1 will not change suddenly, the input end of the NAND gate U1A inputs a low level, and the output end of the NAND gate U1A outputs a low level to the input end of the NAND gate U1B. The output end of the NAND gate U1B outputs a low level. At this time, the switch tube Q4 and the switch tube Q2 are turned on in sequence, and the main controller 6 detects the power-on signal through SW-DE1; the main controller 6 outputs a high level of PW_CL to turn on the switch tube Q3, and the switch tube Q2 is controlled by the switch tube Q3.

[0086] Complete a startup.

[0087] (2) If the moving contact of the sliding switch SW1 is continuously connected to the first static contact NC, when the capacitor C1 is fully charged, a high level is input to the input end of the NAND gate U1A, and the output end of the NAND gate U1A outputs a high level to the input end of the NAND gate U1B. The output end of the NAND gate U1B outputs a high level to control the switch tube Q4 to stop working and enter a low power consumption state.

[0088] When the power tool is turned on and runs to low battery and is shut down by software, if the user forgets to slide the sliding switch SW1 to the POWER-OFF state (i.e., the moving contact of the sliding switch SW1 is continuously connected to the first static contact NC), because the capacitor C1 is fully charged, the switch tube Q4 has been turned off long ago, and the standby current of the double NAND gate is maintained at about 4uA (the power supply of the double NAND gate is 3V~18V. When the voltage of the battery pack 7 is lower than 3V, the double NAND gate will not work and will wait until it is recharged before working again to avoid the battery pack 7 from running out of power), and Q5 and the peripheral circuits also maintain a current of several uA, and the total current is within about 15uA. In this way, the power tool can be maintained for more than 6 months after low battery, thereby avoiding the risk of battery pack 7 being scrapped.

[0089] 2. Shutdown Control

[0090] When the moving contact of the sliding switch SW1 is connected to the second static contact ON, the switch tube Q1A is turned on, and a shutdown signal is output to the main controller 6 through the port SW-DE2. The main controller 6 outputs a low level through PW_CL, so that the switch tube Q3 is turned off, the switch tube Q2 is turned off, the main power supply circuit is disconnected, and physical shutdown and software shutdown are performed.

[0091] In the embodiment of the present invention, the first trigger module 4 is connected in series between the sliding switch SW1 and the third switch module 3, and the hardware startup and the software startup are controlled in sequence to achieve fast startup while ensuring the normal operation of the circuit; and by outputting a shutdown signal to control the third switch module 3 to stop working after a preset time period, even if the startup circuit corresponding to the first switch module 1 is always connected to the battery through the sliding switch SW1 after power-on, it can be stopped by the third switch module 3, so that the power-on circuit of the startup circuit only needs an extremely low static current, thereby greatly reducing the startup energy consumption of the circuit, effectively improving the battery life of the battery pack 7, and avoiding the risk of scrapping the battery pack 7 due to forgetting to turn off the sliding switch SW1.

[0092] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A low power switch circuit for electric tools, characterized in that: include: A first switch module connected in series to the main power supply circuit; A second switch module and a third switch module connected to the control end of the first switch module; A first trigger module and a second trigger module connected to the slide switch; A main controller connected to the second switch module, the third switch module, and the second trigger module; The main controller collects the state feedback of the sliding switch or the state change of the third switch module through the second trigger module; and then drives the first switch module to turn on or off the main power supply circuit by controlling the state change of the second switch module; After the first trigger module is connected to the battery pack power supply through the sliding switch, the first trigger module outputs a start signal to control the third switch module to drive the first switch module to turn on the main power supply circuit; and after a preset time period, the first trigger module outputs a shutdown signal to control the third switch module to stop working, and the first trigger module enters a low-power standby state.

2. A low power consumption on / off circuit for an electric tool as claimed in claim 1, characterized in that: The sliding switch includes a first static contact, a second static contact and a moving contact, one end of the moving contact is electrically connected to the battery pack, and the other end is connected to the first static contact or the second static contact; the first static contact is connected to the input end of the first trigger module, and the second static contact is connected to the input end of the second trigger module.

3. A low power consumption on / off circuit for an electric tool as claimed in claim 2, characterized in that: The first trigger module includes a NAND gate U1A, a NAND gate U1B, a resistor R1, a capacitor C1 and a capacitor C2; one end of the resistor R1 is connected to the first static contact of the sliding switch, and the other end is connected to the input end of the NAND gate U1A; the input end of the NAND gate U1B is connected to the output end of the NAND gate U1A, and the output end is connected to the control end of the third switch module; one end of the capacitor C1 is connected to the other end of the resistor R1, and the other end is grounded; one end of the capacitor C2 is connected to the ADD pin of the NAND gate U1A, and the other end is grounded; When the moving contact of the sliding switch is connected to the first static contact, the battery pack charges the capacitor C1 through the resistor R1. Since the voltage across the capacitor C1 will not change suddenly, at this time, the input end of the NAND gate U1A inputs a low level, and the output end of the NAND gate U1A outputs a low level to the input end of the NAND gate U1B. The output end of the NAND gate U1B outputs a low level to control the first switch module to drive the first switch module to turn on the main power supply circuit; The main controller collects the state change of the third switch module, and then controls the second switch module to replace the third switch module, so as to drive the first switch module to turn on the main power supply circuit; When the capacitor C1 is fully charged, the input end of the NAND gate U1A inputs a high level, and the output end of the NAND gate U1A outputs a high level to the input end of the NAND gate U1B, and the output end of the NAND gate U1B outputs a high level to control the first switch module to stop working and enter a low power consumption state.

4. A low power consumption on / off circuit for an electric tool as claimed in claim 3, characterized in that: The second trigger module includes a signal trigger module, which includes a switch tube Q1A, a resistor R2, a resistor R3, a resistor R4 and a capacitor C3; the first end of the switch tube Q1A is connected to the power supply end through the resistor R2, the second end is grounded, and the control end is connected to the second static contact of the sliding switch through the resistor R3; one end of the capacitor C3 is connected to the second static contact of the sliding switch, and the other end is grounded; one end of the resistor R4 is connected to the control end of the switch tube Q1A, and the other end is connected; the first end of the switch tube Q1A is also connected to the main controller; When the moving contact of the sliding switch is connected to the second static contact, the switch tube Q1A is turned on and outputs a shutdown signal to the main controller. The main controller drives the first switch module to disconnect the main power supply circuit by controlling the second switch module to perform physical shutdown and software shutdown.

5. A low power consumption on / off circuit for an electric tool as claimed in claim 4, characterized in that: The second trigger module further includes a discharge module, which includes a switch tube Q1B, a resistor R5 and a resistor R6; a first end of the switch tube Q1B is connected to one end of the capacitor C2, a second end is grounded, and a control end is connected to the second static contact through the resistor R5; one end of the resistor R6 is connected to the control end of the switch tube Q1B, and the other end is grounded; When the moving contact of the slide switch is connected to the second static contact, the switch tube Q1B is turned on, and the electric energy in the capacitor C2 is discharged through the switch tube Q1B to prepare for the next quick start.

6. A low power consumption on / off circuit for an electric tool as claimed in claim 1, characterized in that: The first switch module includes a switch tube Q2, a resistor R7, a diode D1 and a capacitor C4. The first end of the switch tube Q2 is connected to the rear-end load, the second end is connected to the battery pack, and the control end is connected to the second switch module and the third switch module; the positive electrode of the diode D1 is connected to the control end of the switch tube Q2, and the negative electrode is connected to the second end of the switch tube Q2; the resistor R7 is connected in parallel with the diode D1; one end of the capacitor C4 is connected to the control end of the switch tube Q2, and the other end is grounded.

7. A low power consumption on / off circuit for an electric tool as claimed in claim 1, characterized in that: The second switch module includes a switch tube Q3, a resistor R8, a resistor R9, a resistor R10, a capacitor C5 and a diode D2; the first end of the switch tube Q3 is connected to the control end of the first switch module, the second end is grounded through the resistor R9, and the control end is connected to the output end of the first switch module through the resistor R8; one end of the resistor R10 is connected to the control end of the switch tube Q3, and the other end is grounded; the capacitor C5 is connected in parallel with the resistor R10; the positive electrode of the diode D2 is connected to the main controller, and the negative electrode is connected to the control end of the switch tube Q3; The main controller drives the switch tube Q3 to be turned on or off by changing the signal input to the positive electrode of the diode D2, thereby changing the potential of the control end of the first switch module and turning on or off the main power supply circuit.

8. A low power consumption on / off circuit for an electric tool as claimed in claim 4, characterized in that: The third switch tube includes a switch tube Q4, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a diode D3 and a diode D4; The first end of the switch tube Q4 is connected to the cathode of the diode D3 and the cathode of the diode D4, the second end is grounded, and the control end is connected to the output end of the first trigger module through the resistor R13; The anode of the diode D3 is connected to the control end of the first switch module through the resistor R11; the anode of the diode D4 is connected to the main controller, and is used to feed back the working state of the switch tube Q4 to the main controller; The two ends of the resistor R12 are respectively connected to the first end and the control end of the switch tube Q4; one end of the resistor R14 is connected to the battery pack, and the other end is connected to the control end of the switch tube Q4 through the resistor R13; After the first trigger module is connected to the battery pack power supply through the sliding switch, the first trigger module outputs a start signal to control the switch tube Q4 to turn on, thereby driving the first switch module to turn on the main power supply circuit; at the same time, the main controller receives a power-on signal through the positive electrode of the diode D4, thereby controlling the second switch module to replace the switch tube Q4 to drive the first switch module to turn on the main power supply circuit.

9. A low power consumption on / off circuit for an electric tool as claimed in claim 6, characterized in that: The switch tube Q2 is an N-channel MOS tube or a P-channel MOS tube.

10. A low power consumption on / off circuit for an electric tool as claimed in any one of the preceding claims, characterized in that: The battery pack is a lithium battery or a lead-acid battery.

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