Switching circuit and electronic equipment

Abstract

The invention discloses a switching circuit and electronic equipment, a protection unit is connected between a battery and a load, the input end of a starting unit is connected with the battery, and the output end of the starting unit is connected with the control end of the protection unit; the input end of the control unit is connected between the protection unit and the load, and the output end of the control unit is connected with the control end of the protection unit; the control unit is used for controlling the protection unit to maintain the on state when the output voltage of the battery is larger than the protection voltage, and controlling the protection unit to be switched to the off state when the output voltage of the battery is smaller than or equal to the protection voltage. Through the arrangement of the switching circuit, connection with a rear-end load and an internal circuit power supply end can be disconnected in time under the condition that battery undervoltage is detected or the control unit receives a disconnection signal, so that quiescent current in the switching circuit is reduced; the single-time use time of the battery is prolonged; meanwhile, the battery is protected; and the battery damage risk caused by over-discharge is avoided.

Description

Technical Field

[0001] The present invention relates to the field of circuits, and in particular to a switching circuit and electronic equipment. Background Art

[0002] In battery-powered applications, the battery's quiescent current (IQ) is also called the operating quiescent current, standby current, or current in sleep mode. Excessive quiescent current can cause high standby power consumption during circuit operation, shortening the battery's single-use life. Furthermore, even when the battery is low and shut down, a high quiescent current can still exist, posing risks such as over-discharge, leading to damage or shortened battery life. Reducing the quiescent current output after the battery is shut down is a key concern in circuit design. Summary of the Invention

[0003] In order to solve the above problems, an embodiment of the present invention provides a switching circuit and an electronic device, which can effectively disconnect the circuit connection between the battery and the load and the power supply end of the internal circuit through the coordinated operation of various internal circuits, reduce the static current, and thus extend the single use time and service life of the battery.

[0004] According to a first aspect of an embodiment of the present invention, there is provided a switch circuit connected between a battery and a load, the switch circuit comprising a start-up unit, a control unit, and a protection unit; The protection unit is connected between the battery and the load, and is used to control the conduction and shutdown of the battery and the load; the input end of the starting unit is connected to the battery, and the output end of the starting unit is connected to the control end of the protection unit; the starting unit is used to control the protection unit to be in the conduction state within a preset time period, so that the battery supplies power to the load and the control unit through the protection unit; the input end of the control unit is connected between the protection unit and the load, and the output end of the control unit is connected to the control end of the protection unit; the control unit is used to control the protection unit to maintain the conduction state when the output voltage of the battery is greater than the protection voltage, and to control the protection unit to switch to the disconnection state when the output voltage of the battery is less than or equal to the protection voltage.

[0005] According to the first aspect, in one possible implementation, a first switch is provided between the battery and the starting unit, a first end of the first switch is connected to the battery, and a second end of the first switch is connected to the starting unit, and the first switch is used to open and close the path between the battery and the starting unit; the starting unit includes a first capacitor, a first resistor, a second resistor, and a first switching tube; the first capacitor, the first resistor, and the second resistor are connected in series in sequence, the control end of the first switching tube is connected between the first resistor and the second resistor, the input end of the first switching tube is connected to the control end of the protection unit, and the output end of the first switching tube is grounded.

[0006] According to the first aspect, in a possible implementation, the startup unit further includes a first diode and a third resistor, the cathode of the first diode is connected between the first capacitor and the first resistor, the anode of the first diode is grounded, one end of the third resistor is connected to the first end of the first capacitor, and the other end of the third resistor is grounded.

[0007] According to the first aspect, in one possible implementation, the detection end of the control unit is connected to the battery, and the control unit includes a control chip and a second switching tube; the power supply end of the control chip is connected between the protection unit and the load; the control end of the control chip is connected to the control end of the second switching tube, the detection end of the control chip is connected to the battery, and the output end of the second switching tube is grounded.

[0008] According to the first aspect, in a possible implementation, the protection unit includes a relay and a fifth resistor, wherein the relay includes a relay inductor and a relay switch; the fifth resistor is connected between the first end of the relay inductor and the input end of the second switch tube, the second end of the first switch is respectively connected to the second end of the relay inductor and one end of the relay switch, and the other end of the relay switch is connected to the load.

[0009] According to the first aspect, in a possible implementation, the protection unit further includes a second diode, an anode of the second diode is connected to the first end of the relay inductor, and a cathode of the second diode is connected to the second end of the relay inductor.

[0010] According to the first aspect, in a possible implementation, the startup unit further includes a second capacitor, and the control unit further includes a third capacitor; one end of the second capacitor is connected to the control end of the first switch tube, and the other end of the second capacitor is grounded; one end of the third capacitor is connected to the control end of the second switch tube, and the other end of the third capacitor is grounded.

[0011] According to the first aspect, in a possible implementation, the switching circuit further includes a detection unit connected between the control unit and the battery; the detection unit is used to detect the voltage of the battery based on a working signal output by the control unit.

[0012] According to the first aspect, in a possible implementation, a third diode is provided between the second end of the first switch and the first capacitor, the anode of the third diode is connected to the second end of the first switch, and the cathode of the third diode is connected to the first end of the first capacitor.

[0013] According to a second aspect of an embodiment of the present invention, an electronic device is provided, comprising a load, a battery, and the switching circuit according to any implementation of the first aspect, wherein the switching circuit is connected between the load and the battery.

[0014] Beneficial effects of the present invention: The switching circuit provided in the embodiment of the present application includes a starting unit, a control unit and a protection unit. The starting unit can trigger the protection unit to turn on, so that the battery supplies power to the control unit and the load. The control unit can disconnect the battery from the rear-end load and the internal circuit power supply end in time through the protection unit when it detects that the battery is undervoltage or the control unit receives a disconnection signal (for example, the operator sends a disconnection signal through remote control or the control unit automatically detects a battery abnormality), thereby reducing the static current in the switching circuit, extending the single use time of the battery, and protecting the battery from the risk of battery damage caused by excessive discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the connection between a switch circuit, a load, and a battery provided in an embodiment of the present application; Figure 2 This is a schematic diagram of another connection between a switch circuit, a load, and a battery provided in an embodiment of the present application; Figure 3 This is a schematic structural diagram of a starting unit provided in an embodiment of the present application; Figure 4 This is a schematic structural diagram of another starting unit provided in an embodiment of the present application; Figure 5 This is a schematic structural diagram of a control unit provided in an embodiment of the present application; Figure 6 This is a schematic structural diagram of a protection unit provided in an embodiment of the present application; Figure 7This is a schematic structural diagram of another protection unit provided in an embodiment of the present application; Figure 8 This is a topological diagram of a switching circuit provided in an embodiment of the present application; Figure 9 This is another schematic diagram of the connection between a switch circuit, a load and a battery provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] To enable those skilled in the art to better understand the technical solution of the present application, the present application is described in detail below in conjunction with the accompanying drawings and specific embodiments. Although the drawings and specific embodiments describe exemplary embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein.

[0017] The words "first", "second" and similar terms used in this application do not indicate any order, quantity or importance, but are only used to distinguish. The words "including" and similar terms used in this application mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of also including other elements. The technical solution of this application is not limited to the execution order described in the embodiments. The various steps in the execution order can be combined, decomposed, or swapped, as long as the logical relationship of the execution content is not affected.

[0018] All terms used in this application (including technical or scientific terms) have the same meaning as understood by a person of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in common dictionaries, for example, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein. Techniques and devices known to a person of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques and devices should be considered part of the specification.

[0019] First, the relevant terms involved in the application examples are explained.

[0020] Quiescent current (IQ), also known as operating quiescent current, standby current, or current in sleep mode, refers to the minimum current consumption of an electronic device or circuit when it is battery-powered and has no signal input, is in standby, or is idle. It is a key parameter for evaluating circuit standby power consumption.

[0021] In battery-powered applications, quiescent current primarily consists of static circuit components (such as bias resistors and transistor leakage), sensor standby power consumption, and the current drawn by chips (such as microcontrollers and voltage regulators) in sleep mode. It's typically measured in microamperes (μA) or milliamperes (mA). For example, the IQ of a low-power microcontroller can be as low as a few microamperes, while that of a standard chip might be in the tens of milliamperes.

[0022] Excessive quiescent current, on the one hand, causes high standby power consumption during circuit standby, shortening the battery's single-use life. On the other hand, even when the battery is low and the output is shut down, a high quiescent current still exists, which can lead to risks such as over-discharge, resulting in damage or a shortened battery life. Therefore, the amount of quiescent current directly affects key battery performance indicators such as single-use life and service life. Reducing the quiescent current output after the battery is shut down is a key concern in circuit design.

[0023] In order to solve the above problems, the embodiment of the present application provides a switch circuit that can effectively disconnect the circuit connection between the battery and the load and the internal circuit power supply end through the cooperation of various internal circuits, reduce the static current, and thus extend the single use time and service life of the battery. Figure 1 As shown, Figure 1 The diagram is a schematic diagram of a connection between a switch circuit, a load, and a battery provided in an embodiment of the present application. The switch circuit is connected between the battery and the load and includes a start-up unit, a control unit, and a protection unit.

[0024] The protection unit is connected between the battery and the load, and is used to control the on and off of the battery and the load.

[0025] The input end of the starting unit is connected to the battery, and the output end of the starting unit is connected to the control end of the protection unit; the starting unit is used to control the protection unit to be in a conductive state within a preset time period, so that the battery supplies power to the load and the control unit through the protection unit.

[0026] The input terminal of the control unit is connected between the protection unit and the load, and the output terminal of the control unit is connected to the control terminal of the protection unit. The control unit is configured to control the protection unit to maintain an on state when the output voltage of the battery is greater than a protection voltage, and to control the protection unit to switch to an off state when the output voltage of the battery is less than or equal to the protection voltage.

[0027] The switching circuit provided in the embodiment of the present application enables the battery to supply power to the control unit and the load after the starting unit triggers the protection unit to turn on. The control unit can promptly disconnect the battery from the rear-end load and the internal circuit power supply end through the protection unit when it detects battery undervoltage (i.e., the voltage is less than a preset value) or the control unit receives a disconnect signal (for example, the operator sends a disconnect signal through remote control or the control unit automatically detects a battery abnormality), thereby reducing the static current in the switching circuit, extending the single use time of the battery, and protecting the battery from the risk of battery damage caused by excessive discharge.

[0028] In some embodiments, a battery is a device that converts chemical energy into electrical energy through a chemical reaction. It consists of one or more electrochemical units (cells), each containing positive and negative electrodes, an electrolyte, and a separator. It can continuously supply current in a closed circuit. Its core function is to store and release electrical energy.

[0029] The battery in this embodiment can be a lead-acid battery, a lithium-ion battery, a nickel-cadmium battery, an alkaline battery, or the like, which is used to provide stable direct current.

[0030] Specifically, the preset value may be a voltage value when the battery is exhausted and in an undervoltage state.

[0031] like Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of another connection between a switch circuit, a load, and a battery provided in an embodiment of the present application. Figure 3 This is a structural diagram of a starting unit provided in an embodiment of the present application.

[0032] In some embodiments, a first switch SW2 is provided between the battery and the starting unit, wherein a first end of the first switch SW2 is connected to the battery, and a second end of the first switch SW2 is connected to the starting unit, and the first switch SW2 is used to open and close the path between the battery and the starting unit.

[0033] The startup unit includes a first capacitor C36, a first resistor R118, a second resistor R119, and a first switch Q13. The first capacitor C36, the first resistor R118, and the second resistor R119 are connected in series. The control terminal of the first switch Q13 is connected between the first resistor R118 and the second resistor R119. The input terminal of the first switch Q13 is connected to the control terminal of the protection unit, and the output terminal of the first switch Q13 is grounded.

[0034] It should be noted that the grounding in the embodiment of the present application can be connected to the negative electrode of the battery to achieve grounding. In other embodiments, the grounding can also be connected to the ground wire of the switching circuit instead of the negative electrode of the battery.

[0035] In some embodiments, the first switch transistor Q13 may be a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET).

[0036] For example, the first switch transistor Q13 can be an N-channel enhancement-mode MOSFET (hereinafter referred to as MOS transistor). The first switch transistor Q13 can also be other types of MOSFETs (such as P-channel enhancement-mode MOSFETs or N-channel depletion-mode MOSFETs), or other types of semiconductor switching devices, such as GTRs, IGBTs, GTOs, SCRs, or other suitable devices.

[0037] MOS tubes are voltage-controlled devices that react sensitively to voltage changes. The on and off of MOS tubes can be well controlled by voltage changes.

[0038] In this embodiment, the first control terminal, the first input terminal, and the first output terminal of the first switch tube Q13 may correspond to the gate, the source, and the drain of the MOS tube, respectively.

[0039] The first capacitor C36 is in an uncharged state before the first switch SW2 is closed. For example, in this embodiment, the first capacitor C36, the first resistor R118, and the second resistor R119 can be connected in series. When the first switch SW2 is turned on, since the first capacitor C36 is in an uncharged state, a brief charging current is generated, and the voltage across the first capacitor C36 gradually increases from 0 volts. Therefore, before the first capacitor C36 is fully charged, the direct current in the startup unit can pass through the first capacitor C36. After the current flows out of the positive electrode of the battery, it flows through the first capacitor C36, the first resistor R118, and the second resistor R119 in sequence, and then flows into the negative electrode of the battery.

[0040] Through the above current loop, when the battery charges the first capacitor C36, the gate of the first switch tube Q13 receives a turn-on voltage, causing the source and drain of the first switch tube Q13 to conduct. This turns the startup unit on. When the battery fully charges the first capacitor C36, the voltage across the first capacitor C36 equals the battery voltage, the charging current drops to 0 amps, and the first capacitor C36 becomes an "open circuit," preventing direct current from passing through. At this point, the gate voltage of the first switch tube Q13 drops to 0 volts, and the source and drain of the first switch tube Q13 are disconnected. This turns the startup unit off.

[0041] By configuring the startup unit described above and utilizing the DC-passing and AC-blocking properties of the first capacitor C36, the startup unit can be turned on within a certain period of time to start the subsequent circuits. The control unit will then take over the control of the subsequent protection unit, thereby disconnecting the battery from the back-end load and the internal circuit power supply in the event of a battery undervoltage or the control unit receiving a disconnect signal. Furthermore, the startup unit can also activate the protection unit when the protection unit and control unit are disconnected, reducing the quiescent current loss of the switch circuit during standby mode and extending the battery's single-use duration.

[0042] In some embodiments, the capacity of the first capacitor C36 can be 4.7 μF, the resistance of the first resistor R118 can be set to 10 KΩ, the resistance of the second resistor R119 can be set to 10 KΩ, and the time constant is: τ=RC=(10K+10K)*4.7μF=94ms; It takes approximately 5 τ to fully charge the first capacitor C36, so the time it takes to fully charge the first capacitor C36 is 94ms*5=470ms.

[0043] It should be noted that the first capacitor C36 , the first resistor R118 , and the second resistor R119 may also be connected in series after their order is arbitrarily reversed, and this embodiment does not specifically limit this.

[0044] like Figure 4 As shown, Figure 4 This is a structural diagram of another starting unit provided in an embodiment of the present application.

[0045] In some embodiments, the startup unit may further include a first diode D28 and a third resistor R207, wherein the cathode end of the first diode D28 is connected to the second end of the first capacitor C36, the anode end of the first diode D28 is grounded, one end of the third resistor R207 is connected to the first end of the first capacitor C36, and the other end of the third resistor R207 is grounded.

[0046] In this embodiment, when the first capacitor C36 is fully charged, after the first switch SW2 is disconnected, the first capacitor C36 can discharge through the closed loop formed by the third resistor R207 and the first diode D28. Since the startup unit fully charges the first capacitor C36 during startup, after the first switch SW2 is disconnected, the first capacitor C36 needs to discharge the energy stored in it through the discharge loop so that the startup unit can operate normally when the first switch SW2 is reclosed. Specifically, the current can flow from the first end of the first capacitor C36 through the third resistor R207, the anode of the first diode D28, the cathode of the first diode D28, and back to the second end of the first capacitor C36.

[0047] It should be noted that the resistance of the third resistor R207 can be set to 1MΩ, so that when the first switch SW2 is closed, the current of the positive electrode current of the power supply flowing back to the negative electrode of the battery through the third resistor R207 is very small, the loss caused is very small, and the purpose of energy saving is achieved.

[0048] Through the above configuration, the startup unit can be repeatedly started up through the discharge circuit provided by the first diode D28 and the third resistor R207, thereby preventing the startup unit from being unable to work normally and starting the protection unit when the first switch SW2 is closed again because the first capacitor C36 is already fully charged.

[0049] like Figure 5 As shown, Figure 5 This is a structural diagram of a control unit provided in an embodiment of the present application.

[0050] In some embodiments, a detection terminal of the control unit is connected to the battery. The control unit includes a control chip U20 and a second switch Q14. A power supply terminal Vcc1 of the control chip is connected between the protection unit and the load. A control terminal b1 of the control chip is connected to the control terminal of the second switch. A detection terminal BATVCC_CTRL of the control chip is connected to the battery. The output terminal of the second switch Q14 is grounded.

[0051] It should be noted that the control chip U20 of the embodiment of the present application can be a microcontroller unit (MCU), a microprocessor (MPU), a system on chip (SOC), a digital signal processor (DSP), a graphics processing unit (GPU), etc., which are integrated circuits used to execute program instructions, process data and control system operation.

[0052] In this embodiment, the second switch tube Q14 may be an NPN transistor, the second control terminal of the second switch tube Q14 is the base of the transistor, and the second input terminal and the second output terminal are the collector and emitter of the transistor respectively.

[0053] The transistor is a current-controlled device that responds sensitively to current changes. The conduction and shutdown of the transistor can be well controlled by current changes.

[0054] In some embodiments, as Figure 5As shown, a fourth resistor R120 can be set between the control terminal b1 and the second control terminal of the control chip U20. The fourth resistor R120 in the control unit plays a current limiting role to prevent excessive current flowing into the base of the second switch tube Q14 from damaging the second switch tube Q14.

[0055] In some embodiments, after the power supply terminal Vcc1 of the control chip U20 receives power from the main circuit (i.e., the main circuit consisting of the battery, protection unit, and load), the control chip U20 starts operating. The control chip U20 sends a turn-on signal through the control terminal, causing the voltage at the control terminal to change from a low voltage to a high voltage. This causes current to flow from the control terminal through the fourth resistor R120 and into the base of the second switch Q14. This triggers the second switch Q14 to turn on, causing the collector and emitter of the second switch Q14 to conduct.

[0056] In some embodiments, as Figure 5 As shown, a fifth resistor can be provided between the control terminal and the second input terminal of the protection unit. The fifth resistor also serves as a current limiter. Because the input terminal of the first switching transistor Q13 is connected to the input terminal of the second switching transistor Q14, the fifth resistor can also prevent excessive current from flowing into the first switching transistor Q13 or the second switching transistor Q14, thereby preventing the first switching transistor Q13 or the second switching transistor Q14 from being damaged due to overheating.

[0057] It should be noted that the fifth resistor can be Figure 5 The two resistors (R115 and R116) shown are connected in parallel. It can also be one resistor, or more than two resistors can be connected in parallel or in series. This embodiment is not limited here.

[0058] In some embodiments, the time it takes for the control chip U20 to receive a power start and issue an action signal is 60ms. Through the configuration of the control unit described above, when the startup unit starts the protection unit, the control chip U20 receives the power start and controls the conduction of the second switch Q14, thereby controlling the protection unit to remain in the on state and maintain the protection unit's operation. Even after the startup unit's first capacitor C36 is fully charged and the startup unit is disconnected, the control unit can still effectively maintain the protection unit's continued operation.

[0059] It should be noted that, in some other embodiments, the second switch tube Q14 may also be a PNP transistor.

[0060] like Figure 6 As shown, Figure 6 This is a structural diagram of a protection unit provided in an embodiment of the present application.

[0061] In some embodiments, the protection unit may include a relay and a fifth resistor, wherein the relay includes a relay inductor RLY1 -A and a relay switch RLY1 -B.

[0062] The fifth resistor is connected between the first end of the relay inductor RLY1-A and the input end of the second switch tube Q14. The second end of the first switch SW2 is connected to the second end of the relay inductor RLY1-A and one end of the relay switch RLY1-B respectively. The other end of the relay switch RLY1-B is connected to the load.

[0063] In some embodiments, the relay may be an electromagnetic relay, capable of controlling the on / off switching of a high-current circuit using a low-current signal. When current flows through relay inductor RLY1-A, it generates a magnetic field, attracting relay switch RLY1-B to close, thereby turning on the protection unit. When current is removed from relay inductor RLY1-A, the magnetic field disappears, and relay switch RLY1-B returns to its original position due to the action of a return spring. Relay switch RLY1-B then opens, disconnecting the protection unit.

[0064] Specifically, when the first switch SW2 is closed, the first switch Q13 in the startup unit is turned on. Current flows from the positive electrode of the battery, sequentially through the relay inductor RLY1-A, the fifth resistor, and the first switch Q13, before returning to the negative electrode of the battery. At this point, the relay actuates, closing the relay switch RLY1-B, allowing the battery to power the load and the power supply. When the power supply provides power to the control unit, the control chip U20 in the control unit activates and triggers the second switch Q14, closing the collector and emitter of the second switch Q14. At this point, the positive current from the battery can flow sequentially through the relay inductor RLY1-A, the fifth resistor, and the second switch Q14, before returning to the negative electrode of the battery. When the first capacitor C36 in the startup unit is fully charged, disconnecting the first switch Q13, the second switch Q14 in the control unit remains on, maintaining current flow through the relay inductor RLY1-A in the protection unit. This maintains the closed state of the relay switch RLY1-B, allowing the battery to continue to power the load and the power supply.

[0065] In some embodiments, the startup unit operating time can be 5 τ, i.e., the time it takes for the first capacitor C36 to fully charge is 94ms * 5 = 470ms, while the time it takes for the control chip U20 in the control unit to receive power and send a turn-on signal to the second switch Q14 is 60ms. Therefore, during the time it takes for the startup unit to start the protection unit and maintain the protection unit on, the control unit has sufficient time to start and cause the second switch Q14 to initiate a turn-on action, maintaining the protection unit's continued operation. This configuration avoids the situation where the control unit fails to operate after the startup unit disconnects, resulting in a highly reliable and stable switching circuit.

[0066] In this embodiment, the presence of a relay in the protection unit effectively isolates the high-current wiring connecting the load from the low-current wiring of the starting unit and control unit, preventing interference between the circuits. Furthermore, by controlling the relay, a low current can control a high current, saving battery power, extending the battery's single-use life, and improving energy efficiency.

[0067] like Figure 7 As shown, Figure 7 This is a structural diagram of another protection unit provided in an embodiment of the present application.

[0068] In some embodiments, the protection unit further includes a second diode D29 , an anode terminal of the second diode D29 is connected to the first end of the relay inductor RLY1 -A, and a cathode terminal of the second diode D29 is connected to the second end of the relay inductor RLY1 -A.

[0069] It's important to note that relay inductor RLY1-A itself is an inductive element. The magnetic field within its coil fluctuates during power-on and power-off cycles. When power is removed from relay inductor RLY1-A, the magnetic field energy is converted into electrical energy, generating a high induced electromotive force (spike voltage) and induced current across relay inductor RLY1-A. Excessively high spike voltages can damage other electronic components connected to the relay, such as switches, capacitors, and resistors. Furthermore, spike voltages generate high-frequency electromagnetic waves, which can interfere with the operation of surrounding electronic devices. For example, these spikes can cause noise on nearby radios or streaks on TV screens.

[0070] In some embodiments, while the control unit maintains the protection unit on, when the control chip U20 receives a circuit shutdown signal, the control terminal b1 of the control chip U20 changes from a high potential to a low potential, turning off the second switch Q14. At this point, both the first switch Q13 and the second switch Q14 are off, and no current flows through the relay inductor RLY1-A. This causes the reset spring to open the relay switch RLY1-B, disconnecting the protection unit.

[0071] Because relay inductor RLY1-A generates a high induced electromotive force and induced current when the second switch Q14 is disconnected, the provision of second diode D29 allows the energy in relay inductor RLY1-A to be effectively released through second diode D29, preventing damage to other important circuit components (such as first switch Q13 and second switch Q14). Specifically, when the protection unit is operating, the current in relay inductor RLY1-A flows into the first terminal of relay inductor RLY1-A and out of the second terminal of relay inductor RLY1-A. When the second switch Q14 is disconnected, relay inductor RLY1-A continues to maintain a continuous current flow. Therefore, the induced current generated by relay inductor RLY1-A flows out of the first terminal of relay inductor RLY1-A, passes through the anode of second diode D29, and then flows back to the second terminal of the relay.

[0072] In some embodiments, the second diode D29 may be a single diode or two diodes connected in parallel, which is not specifically limited in the embodiment of the present application.

[0073] like Figure 8 As shown, Figure 8 This is a topological diagram of a switching circuit provided in an embodiment of the present application. In the figure, the VIN interface is connected to the positive electrode of the battery, the GND is connected to the negative electrode of the battery, OUT1 is the power supply end, OUT2 is connected to the load, and BAT_RL_ON is connected to the control terminal b1 of the control chip.

[0074] In some embodiments, a snubber circuit may be connected in parallel across relay switch RLY1-B. The snubber circuit may be a series resistor and capacitor. In other embodiments, the snubber circuit may be two resistors connected in parallel and then a capacitor connected in series (e.g., R50, R55, and C22 in the figure), a single resistor connected in series with a capacitor, or multiple resistors connected in parallel and then a capacitor connected in series. This is not specifically limited in this embodiment of the present application.

[0075] When the relay contacts open, the air between relay switch RLY1-B breaks down, forming an arc. The arc's presence causes current to continue flowing for a period of time, generating a voltage spike. Furthermore, factors such as changes in relay switch RLY1-B's contact resistance and mechanical vibration can also contribute to voltage spikes. If the voltage spike exceeds the withstand voltage rating of relay switch RLY1-B, it can cause damage such as electrolytic corrosion and welding, shortening the relay's service life.

[0076] By configuring the absorption circuit, the capacitor absorbs the energy of the spike voltage, while the resistor limits the capacitor's discharge current, preventing excessive surge current when the relay closes again. This significantly improves the relay's service life and the safety performance of the switch circuit in this embodiment.

[0077] like Figure 8 As shown, in some embodiments, the startup unit further includes a second capacitor C60, and the control unit further includes a third capacitor C61. One end of the second capacitor C60 is connected to the first control terminal, and the other end of the second capacitor C60 is grounded. One end of the third capacitor C61 is connected to the second control terminal, and the other end of the third capacitor C61 is grounded.

[0078] In this embodiment, the second capacitor C60 and the third capacitor C61 stabilize the control voltage and suppress high-frequency interference. Capacitors act as "high-frequency noise discharge channels." By utilizing their capacitive reactance, which decreases with increasing frequency, and by appropriately sizing the capacitors, they can preferentially bypass high-frequency interference (such as power supply ripple and spikes generated by electromagnetic radiation) superimposed on the control signal at the control end of the switch transistor to ground. For example, when the control end input signal is contaminated with high-frequency noise, the capacitive reactance of the parallel capacitors to this noise is very small, far lower than the impedance of the downstream circuit. The noise current is discharged through the capacitors, while the low-frequency control signal (such as the signal from the control chip U20 that turns on the second switch transistor Q14) is transmitted normally due to the large capacitive reactance of the capacitors. This prevents false triggering of the switch transistor caused by interference (such as abnormal collector current caused by transistor base voltage fluctuations), ensuring that the control voltage remains stable within the target range.

[0079] In some embodiments, a pull-down resistor R121 may be connected in parallel to the control stage of the second switch Q14 to provide a specific voltage level to the second switch Q14 to prevent the second switch Q14 from being accidentally turned on. For example, static electricity can easily accumulate when the control terminal is left floating. The parallel resistor can pull the floating terminal to a fixed potential to prevent the static voltage from causing abnormal transistor conduction.

[0080] like Figure 9 As shown, Figure 9 This is another schematic diagram of the connection between a switch circuit, a load and a battery provided in an embodiment of the present application.

[0081] In some embodiments, the switching circuit further includes a detection unit connected between the control unit and the battery; the detection unit is configured to detect the voltage of the battery based on a working signal output by the control unit.

[0082] Specifically, a detection terminal BATVCC_CTRL can be provided between the input terminal of the second switch Q14 and the input terminal of the first switch Q13, connected to the detection unit. When the first switch Q13 and / or the second switch Q14 are on, the potential of the detection terminal BATVCC_CTRL is pulled low, causing the detection unit to begin detecting the battery voltage upon receiving a low-level signal. When the first switch Q13 and the second switch Q14 are off, the potential of the detection terminal BATVCC_CTRL is restored, causing the detection unit to cease detecting the battery voltage upon receiving a high-level signal.

[0083] In some embodiments, the detection unit may also be connected to the control chip U20. When the detection unit detects that the battery is in an undervoltage or abnormal state, it sends a signal to the control chip U20 to disconnect the protection unit. The control chip U20 then disconnects the second switch Q14, disconnecting the relay switch RLY1-B in the protection unit, thereby preventing the battery from being shortened or damaged due to over-discharge or abnormal operation.

[0084] like Figure 8 As shown, in some embodiments, a fourth diode D45 is provided between the detection terminal BATVCC_CTRL and the fifth resistor. The anode of the fourth diode D45 is connected to the fifth resistor, and the cathode of the fourth diode D45 is connected to the detection terminal BATVCC_CTRL. When the potential of the detection terminal BATVCC_CTRL is not pulled low, the presence of the fourth diode D45 prevents current from flowing from the detection terminal BATVCC_CTRL through the loop formed by the fourth diode D45, the fifth resistor, the second diode D29, and the third resistor R207 to the negative electrode of the battery, resulting in leakage current. This improves the stability of the control unit.

[0085] like Figure 8 As shown, in some embodiments, a third diode D14 is provided between the second end of the first switch SW2 and the first end of the delay circuit, the anode of the third diode D14 is connected to the second end of the first switch SW2, and the cathode of the third diode D14 is connected to the first end of the delay circuit.

[0086] The unidirectional conduction characteristics of the third diode D14 provide critical protection against reverse battery connection. When the battery polarity is reversed, the third diode D14 immediately reverses to cutoff, blocking the abnormal current path and preventing reverse voltage from directly acting on sensitive components in the switching circuit, such as transistors and MOS transistors, and damaging them due to overvoltage breakdown or backflow. This design eliminates the need for additional complex circuitry and achieves reliable protection with a minimalist structure. This reduces circuit complexity and the risk of failure, improves system safety and stability, and ensures that the device remains intact even in the event of battery installation errors, effectively extending the life of the switching circuit.

[0087] like Figure 8 As shown, in some embodiments, a jumper resistor R117 can be provided in the switch circuit of the embodiment of the present application. The jumper resistor R117 can be provided as one or more. The resistance of the jumper resistor R117 is 0. The jumper resistor can be used as a debug jumper in the circuit to switch the signal path, compatible with different design solutions to reduce production costs, optimize electromagnetic compatibility performance and reduce interference. Connecting multiple layers of ground planes improves grounding, and is suitable for mass production of patch processes, facilitating wiring, and can replace low-current fuses when necessary.

[0088] An embodiment of the present application further provides an electronic device, comprising a load, a battery, and the switching circuit described in any one of the above embodiments and methods, wherein the switching circuit is connected between the load and the battery.

[0089] The switching circuit of an electronic device may include a starting unit, a control unit, and a protection unit. The starting unit can trigger the protection unit to turn on, allowing the battery to power the control unit and the load. The control unit can promptly disconnect the battery from the rear-end load and the internal circuit power supply end through the protection unit when it detects battery undervoltage or receives a disconnect signal (for example, the operator sends a disconnect signal through remote control or the control unit automatically detects a battery abnormality), thereby reducing the static current in the switching circuit, extending the battery's single-use time, and protecting the battery from the risk of battery damage caused by excessive discharge.

[0090] The electronic device in this embodiment may be, for example, a portable electronic device, a medical electronic device, an emergency electronic device, an energy storage network device, a sensor network device, or other electronic device.

[0091] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the present invention may be practiced without these specific details. Similarly, in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. The claims that follow the detailed description are hereby expressly incorporated into that detailed description, with each claim itself serving as a separate embodiment of the present invention.

[0092] Those skilled in the art will appreciate that the modules in the devices of the embodiments can be adaptively modified and installed in one or more devices different from the embodiments. The modules, units, or components in the embodiments can be combined into one module, unit, or component, and furthermore, they can be divided into multiple submodules, subunits, or subcomponents. This is in addition to at least some of the features and / or processes or units being mutually exclusive.

[0093] It should be noted that the above embodiments illustrate rather than limit the invention and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware.

Claims

1. A switching circuit, characterized in that: Connected between the battery and the load, the switch circuit includes a starting unit, a control unit and a protection unit; The protection unit is connected between the battery and the load, and is used to control the conduction and disconnection of the battery and the load; The input end of the starting unit is connected to the battery, and the output end of the starting unit is connected to the control end of the protection unit; the starting unit is used to control the protection unit to be in a conductive state within a preset time period, so that the battery supplies power to the load and the control unit through the protection unit; The input end of the control unit is connected between the protection unit and the load, and the output end of the control unit is connected to the control end of the protection unit; the control unit is used to control the protection unit to maintain the on state when the output voltage of the battery is greater than the protection voltage, and to control the protection unit to switch to the off state when the output voltage of the battery is less than or equal to the protection voltage.

2. The switching circuit according to claim 1, wherein: A first switch is provided between the battery and the starting unit, wherein a first end of the first switch is connected to the battery, and a second end of the first switch is connected to the starting unit, and the first switch is used to open and close the path between the battery and the starting unit; The startup unit includes a first capacitor, a first resistor, a second resistor and a first switch tube; The first capacitor, the first resistor and the second resistor are connected in series in sequence, the control end of the first switch tube is connected between the first resistor and the second resistor, the input end of the first switch tube is connected to the control end of the protection unit, and the output end of the first switch tube is grounded.

3. The switching circuit according to claim 2, wherein: The startup unit also includes a first diode and a third resistor, the cathode of the first diode is connected between the first capacitor and the first resistor, the anode of the first diode is grounded, one end of the third resistor is connected to the first end of the first capacitor, and the other end of the third resistor is grounded.

4. The switching circuit according to claim 3, wherein: The control unit includes a control chip and a second switch tube; The power supply end of the control chip is connected between the protection unit and the load; The control end of the control chip is connected to the control end of the second switch tube, the detection end of the control chip is connected to the battery, and the output end of the second switch tube is grounded.

5. The switching circuit according to claim 4, wherein: The protection unit includes a relay and a fifth resistor, wherein the relay includes a relay inductor and a relay switch; The fifth resistor is connected between the first end of the relay inductor and the input end of the second switch tube, the second end of the first switch is respectively connected to the second end of the relay inductor and one end of the relay switch, and the other end of the relay switch is connected to the load.

6. The switching circuit according to claim 5, characterized in that: The protection unit further includes a second diode, an anode of the second diode is connected to the first end of the relay inductor, and a cathode of the second diode is connected to the second end of the relay inductor.

7. The switching circuit according to claim 4, wherein: The startup unit further includes a second capacitor, and the control unit further includes a third capacitor; One end of the second capacitor is connected to the control end of the first switch tube, and the other end of the second capacitor is grounded. One end of the third capacitor is connected to the control end of the second switch tube, and the other end of the third capacitor is grounded.

8. The switching circuit according to any one of claims 1 to 7, characterized in that: The switch circuit further includes a detection unit connected between the control unit and the battery; the detection unit is used to detect the voltage of the battery according to the working signal output by the control unit.

9. The switching circuit according to claim 2 or 3, characterized in that: A third diode is provided between the second end of the first switch and the first capacitor, an anode of the third diode is connected to the second end of the first switch, and a cathode of the third diode is connected to the first end of the first capacitor.

10. An electronic device, characterized in that: The electronic device includes a load, a battery, and a switch circuit according to any one of claims 1 to 9, wherein the switch circuit is connected between the load and the battery.

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