Self-locking power supply protection circuit and mainboard

Abstract

The utility model discloses a self-locking type power supply protection circuit and a mainboard. The self-locking type power supply protection circuit is used for supplying power to electric devices. The self-locking power supply protection circuit comprises a power supply output control circuit, a current detection circuit and a self-locking protection control circuit. The output end of the power supply output control circuit is connected with the current input end of the electric device and is used for supplying power to the electric device; the input end of the current detection circuit is connected with the current output end of the electric device, and is used for collecting the output current of the electric device, determining whether the electric device has current abnormity or not based on the output current, and sending a power-off locking signal to the control end of the self-locking protection control circuit when the electric device has the current abnormity; and after receiving the power-off locking signal, the self-locking protection control circuit continuously outputs a power supply termination signal to the power supply output control circuit, so that the power supply output control circuit stops supplying power to the electric device. According to the technical scheme disclosed by the utility model, the power supply safety of the electric device can be obviously enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit control, in particular to a self-locking power supply protection circuit and a mainboard. Background Art

[0002] With the rapid advancement of electronic technology, existing computer devices are increasingly equipped with computing components to perform various computational processing functions. These computing components typically connect to a motherboard (Motherboard). Furthermore, the motherboard provides power to these components, making the power supply security of the motherboard a top priority in current motherboard design.

[0003] Currently, many motherboards lack a self-locking power shutoff feature. For example, when an electrical device experiences an abnormal overcurrent or short circuit, the motherboard's power supply circuitry often does not directly disconnect the device. Instead, it continues to supply power to the abnormal device at the currently set maximum current, causing the device to remain in an overcurrent or short circuit state. Alternatively, the motherboard's power supply circuitry may be immediately restored to the abnormal device after disconnecting it, and this process repeats. This power supply method not only damages the power supply circuitry but also causes more serious damage to the devices. Consequently, existing motherboards offer low power supply security for various devices. Utility Model Content

[0004] In view of this, the present invention provides a self-locking power supply protection circuit and a mainboard, the main purpose of which is to solve the technical problem of low power supply safety of the existing mainboard to various electrical devices.

[0005] To achieve the above-mentioned object, the present invention first provides a self-locking power supply protection circuit for supplying power to electrical devices, wherein the self-locking power supply protection circuit includes a power output control circuit, a current detection circuit, and a self-locking protection control circuit;

[0006] The output end of the power output control circuit is connected to the current input end of the electrical device, so as to supply power to the electrical device;

[0007] The input end of the current detection circuit is connected to the current output end of the electrical device, and is used to collect the output current of the electrical device, determine whether the electrical device is in an abnormal current state based on the output current, and send a power-off locking signal to the control end of the self-locking protection control circuit when the electrical device is in the abnormal current state;

[0008] The output end of the self-locking protection control circuit is connected to the control end of the power output control circuit, and is used to continuously output a power supply termination signal to the power output control circuit after receiving the power-off locking signal, so as to control the power output control circuit to terminate supplying power to the electrical device.

[0009] In one embodiment of the present utility model, the power output control circuit includes a first PMOS transistor and a pull-down resistor; the source of the first PMOS transistor is connected to the external power supply, the drain of the first PMOS transistor is connected to the current input end of the electrical device, and the gate of the first PMOS transistor is connected to the output end of the self-locking protection control circuit for receiving the power supply termination signal; the gate of the first PMOS transistor is also grounded through the pull-down resistor.

[0010] In one embodiment of the present invention, the self-locking power supply protection circuit further includes a first light-emitting diode; the anode terminal of the first light-emitting diode is connected to the drain of the first PMOS transistor, and the cathode terminal of the first light-emitting diode is grounded.

[0011] In one embodiment of the present invention, the self-locking protection control circuit includes a second PMOS transistor, a first NMOS transistor and a second NMOS transistor; the connection end of the gate of the second PMOS transistor, the drain of the first NMOS transistor and the drain of the second NMOS transistor in parallel is connected to the external power supply, the source of the second PMOS transistor is connected to the external power supply, and the connection end of the source of the first NMOS transistor and the source of the second NMOS transistor in parallel is grounded; the gate of the second NMOS transistor is connected to the current detection circuit as the control end of the self-locking protection control circuit, for receiving the power-off locking signal; the connection end of the gate of the first NMOS transistor and the drain of the second PMOS transistor in parallel is connected to the control end of the power output control circuit as the output end of the self-locking protection control circuit, for sending the power supply termination signal.

[0012] In one embodiment of the present invention, the self-locking power supply protection circuit further includes a second light-emitting diode; the anode terminal of the second light-emitting diode is connected to the drain of the second PMOS transistor, and the cathode terminal of the second light-emitting diode is grounded.

[0013] In one embodiment of the present utility model, the current detection circuit includes a voltage comparator, a pull-up resistor, a first current detection resistor, a second current detection resistor, and a third current detection resistor; a first end of the first current detection resistor is connected to the current input terminal of the electrical device, a second end of the first current detection resistor is connected to the inverting input terminal of the voltage comparator and the first end of the second current detection resistor, respectively, and a second end of the second current detection resistor is grounded; a connection end of the first end of the third current detection resistor connected in parallel with the non-inverting input terminal of the voltage comparator is connected to the current output terminal of the electrical device as the input terminal of the current detection circuit, and a second end of the third current detection resistor is grounded; a first end of the pull-up resistor is connected to an external voltage source, and a connection end of the second end of the pull-up resistor connected in parallel with the output terminal of the voltage comparator is connected to the control terminal of the self-locking protection control circuit for sending the power-off lockout signal, wherein when the voltage at the non-inverting input terminal of the voltage comparator is greater than the voltage at the inverting input terminal, the current detection circuit sends the power-off lockout signal to the control terminal of the self-locking protection control circuit.

[0014] In one embodiment of the present invention, the first current detection resistor, the second current detection resistor, and the third current detection resistor are all variable resistors.

[0015] In one embodiment of the present invention, the self-locking protection control circuit also includes a current limiting resistor; the current limiting resistor is connected between the connection end after the gate of the second PMOS transistor, the drain of the first NMOS transistor and the drain of the second NMOS transistor are connected in parallel and the external power supply.

[0016] In one embodiment of the present invention, the self-locking power supply protection circuit further includes a self-locking reset switch; a first end of the self-locking reset switch is connected to the gate of the first NMOS transistor, and a second end of the self-locking reset switch is grounded.

[0017] In addition, to achieve the above-mentioned purpose, the present invention also provides a mainboard including the above-mentioned self-locking power supply protection circuit.

[0018] The present invention provides a self-locking power supply protection circuit and a motherboard, wherein the self-locking power supply protection circuit can supply power to an electrical device through a power output control circuit when the electrical device is in a normal state. Simultaneously, the circuit can detect the output current output by the current loop of the electrical device based on a current detection circuit, and determine whether an abnormal overcurrent or short circuit condition occurs in the electrical circuit of the electrical device by detecting whether the output current increases abnormally. When an abnormal overcurrent or short circuit condition is detected in the electrical circuit of the electrical device, the self-locking protection control circuit continuously locks the current output of the power output control circuit to zero output, preventing the electrical device from obtaining electrical energy from the power output control circuit. This continuously disconnects the mainboard from supplying power to the electrical device, thereby avoiding repeated power supply to abnormal electrical devices and significantly enhancing the safety of the mainboard's power supply to each electrical device.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic structural diagram of a self-locking power supply protection circuit provided by an embodiment of the present utility model is shown;

[0022] Figure 2 A structural schematic diagram of another self-locking power supply protection circuit provided by an embodiment of the present utility model is shown. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0024] To further illustrate the technical means and effects employed by the present invention to achieve its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0025] The following combination Figures 1 to 2 A self-locking power supply protection circuit and a mainboard according to some embodiments of the present invention are described.

[0026] like Figure 1 As shown, one embodiment of the present invention provides a self-locking power supply protection circuit for supplying power to an electrical device 400. The self-locking power supply protection circuit can be installed on a motherboard and serve as a power supply unit for the motherboard to supply power to the electrical devices 400 on the motherboard. Specifically, the self-locking power supply protection circuit includes a power output control circuit 100, a current detection circuit 200, and a self-locking protection control circuit 300.

[0027] The output terminal of the power output control circuit 100 is connected to the current input terminal of the electrical device 400 to supply power to the electrical device 400 so that the electrical device 400 can be in an operating state. Here, the power output control circuit 100 can be connected to an external power source to obtain electrical energy from the external power source and supply power to the electrical device 400. Furthermore, the power output control circuit 100 can be controlled to output an operating current to the electrical device 400 or stop outputting the operating current to the electrical device 400.

[0028] Furthermore, the input terminal of the current detection circuit 200 is connected to the current output terminal of the electrical device 400, and is used to collect the output current of the electrical device 400, determine whether the electrical device 400 is in an abnormal current state based on the output current, and send a power-off lock signal to the control terminal of the self-locking protection control circuit 300 when the electrical device 400 is in an abnormal current state. Specifically, the signal output terminal of the current detection circuit 200 is connected to the control terminal of the self-locking protection control circuit 300 to send the power-off lock signal to the self-locking protection control circuit 300.

[0029] Here, the electrical device 400 receives working current through the current input terminal to obtain power supply, and current flows out from the current output terminal. Here, when the electrical device 400 has an overcurrent or short circuit, the current flowing out of the current output terminal of the electrical device 400 will increase sharply. The current detection circuit 200 can connect the input terminal to the current output terminal of the electrical device 400 to determine whether the output current of the current output terminal of the electrical device 400 has increased and exceeded the normal current range. When the current detection circuit 200 determines that the output current of the current output terminal of the electrical device 400 exceeds the normal current range, it can determine that the electrical device 400 is in an abnormal current state of overcurrent or short circuit, and send a power-off lock signal to the self-locking protection control circuit 300.

[0030] Furthermore, the output end of the self-locking protection control circuit 300 is connected to the control end of the power output control circuit 100, and is configured to continuously output a power supply termination signal to the power output control circuit 100 after receiving the power-off lock signal, so as to control the power output control circuit 100 to terminate the output of the operating current to the electrical device 400, thereby stopping power supply to the electrical device 400. Specifically, after receiving the power-off lock signal, the self-locking protection control circuit 300 enters a self-locking state and continuously outputs a power supply termination signal to the control end of the power output control circuit 100 to control the power output control circuit 100 to stop outputting the operating current to the electrical device 400. This can continuously cut off the power supply from the power output control circuit 100 to the electrical device 400, thereby protecting the power supply end from continuously supplying power to the electrical device 400 at the maximum current.

[0031] The present invention provides a self-locking power supply protection circuit that can supply power to an electrical device through a power output control circuit when the electrical device is in a normal state. Simultaneously, the circuit can detect the loop current output by the current loop of the electrical device based on a current detection circuit, and determine whether an abnormal overcurrent or short circuit condition has occurred in the electrical circuit of the electrical device by detecting whether the loop current has increased abnormally. When an abnormal overcurrent or short circuit condition is detected in the electrical circuit of the electrical device, the self-locking protection control circuit continuously locks the current output of the power output control circuit to zero output, preventing the electrical device from obtaining operating current from the power output control circuit. This continuously disconnects the mainboard from supplying power to the electrical device, thereby significantly enhancing the safety of the mainboard's power supply to each electrical device.

[0032] In an optional embodiment, if Figure 2 As shown, the power output control circuit 100 includes a first PMOS transistor Q1 and a pull-down resistor R1.

[0033] Specifically, the source of the first PMOS transistor Q1 is connected to the external power supply V1 for receiving the operating current through the external power supply V1. The drain of the first PMOS transistor Q1 is connected to the current input terminal of the power-consuming device 400. The gate of the first PMOS transistor Q1 is connected to the output terminal of the self-locking protection control circuit 300 for receiving the power supply termination signal, wherein the power supply termination signal is a high-level signal. Here, the current and voltage output by the external power supply V1 can be controlled and changed.

[0034] Furthermore, the gate of the first PMOS transistor Q1 is also connected to the first end of the pull-down resistor R1, and the second end of the pull-down resistor R1 is grounded. Specifically, when the electrical device 400 is not in an abnormal current state, the gate of the first PMOS transistor Q1 does not receive a high-level power supply termination signal, and the gate voltage of the first PMOS transistor Q1 is pulled down to ground by the pull-down resistor R1, turning on the first PMOS transistor Q1, allowing the external power supply V1 to normally output an operating current to the electrical device 400 through the first PMOS transistor Q1, thereby powering the electrical device 400. Conversely, when the electrical device 400 is in an abnormal current state, the gate of the first PMOS transistor Q1 receives a high-level power supply termination signal, causing the first PMOS transistor Q1 to be turned off, preventing the external power supply V1 from normally outputting an operating current to the electrical device 400 through the first PMOS transistor Q1.

[0035] The embodiment provided in the present application can control whether the power output control circuit outputs the operating current to the electrical device by controlling the conduction and disconnection of the first PMOS transistor. When the self-locking protection control circuit continuously outputs a power supply termination signal to the power output control circuit, the power supply to the electrical device can be continuously disconnected, so that the self-locking power supply protection circuit can continuously disconnect the power supply of the mainboard to the electrical device, thereby significantly enhancing the power supply safety of the mainboard to each electrical device.

[0036] In an optional embodiment, if Figure 2 As shown, the self-locking power supply protection circuit further includes a first light-emitting diode D1; wherein the first light-emitting diode D1 can serve as a normal operating indicator light of the self-locking power supply protection circuit.

[0037] Specifically, the anode terminal of the first light-emitting diode D1 is connected to the drain terminal of the first PMOS transistor Q1, and the cathode terminal of the first light-emitting diode D1 is grounded. When the electrical device 400 is not in an abnormal current state, the first PMOS transistor Q1 is turned on, causing the first light-emitting diode D1 to be powered and emit light. When the electrical device 400 is in an abnormal current state, the first PMOS transistor Q1 is turned off, causing the first light-emitting diode D1 to lose power and not emit light. The embodiments provided in this application can emit a light signal to indicate that the electrical device is operating normally when it is powered on, allowing relevant personnel to intuitively observe the operation of the self-locking power supply protection circuit and the electrical device, thereby improving the functionality of the self-locking power supply protection circuit.

[0038] In an optional embodiment, if Figure 2 As shown, the self-locking protection control circuit 300 includes a second PMOS transistor Q2, a first NMOS transistor Q3 and a second NMOS transistor Q4.

[0039] Specifically, a connection end where the gate of the second PMOS transistor Q2, the drain of the first NMOS transistor Q3, and the drain of the second NMOS transistor Q4 are connected in parallel is connected to the external power supply V1, a source of the second PMOS transistor Q2 is connected to the external power supply V1, and a connection end where the source of the first NMOS transistor Q3 and the source of the second NMOS transistor Q4 are connected in parallel is grounded.

[0040] Furthermore, the gate of the second NMOS transistor Q4 serves as a control terminal of the self-locking protection control circuit 300 and is configured to receive the power-off lockout signal, wherein the power-off lockout signal is a high-level signal. Furthermore, when the current detection circuit 200 determines that the electrical device 400 is not in an abnormal current state such as overcurrent or short circuit, a low-level signal is sent to the gate of the second NMOS transistor Q4.

[0041] Furthermore, the connection end after the gate of the first NMOS transistor Q3 and the drain of the second PMOS transistor Q2 are connected in parallel is connected to the control end of the power output control circuit 100 as the output end of the self-locking protection control circuit 300, and is used to send the power supply termination signal to send the power supply termination signal to the gate of the first PMOS transistor Q1.

[0042] Further, such as Figure 2 As shown, the self-locking protection control circuit 300 also includes a current-limiting resistor R2; the connection end of the gate of the second PMOS transistor Q2, the drain of the first NMOS transistor Q3, and the drain of the first NMOS transistor Q4 in parallel is connected to the first end of the current-limiting resistor R2, and the second end of the current-limiting resistor R2 is connected to the external power supply V1, so that the current-limiting resistor R2 serves to limit the current of the self-locking protection control circuit 300. Furthermore, the self-locking protection control circuit 300 also includes a first current protection resistor R3; the gate of the first NMOS transistor Q3 is connected to the first end of the first current protection resistor R3, and the connection end of the second end of the first current protection resistor R3 and the drain of the second PMOS transistor Q2 in parallel serves as the output end of the self-locking protection control circuit 300.

[0043] During actual operation, when the circuit of the electrical device 400 is normal and there is no overcurrent or short circuit: the gate of the second NMOS transistor Q4 is always in a low level state, and its conduction condition is not met. At this time, the second NMOS transistor Q4 is not turned on, and the gate of the second PMOS transistor Q2 is at a high potential due to the pull-up of the current limiting resistor R2, and the gate of the first NMOS transistor Q3 is pulled down to ground by the pull-down resistor R1, so that the second PMOS transistor Q2 and the first NMOS transistor Q3 are not turned on, and the gate of the first PMOS transistor Q1 is continuously at a low level.

[0044] Conversely, when an overcurrent or short circuit occurs in the circuit of the electrical device 400: the current detection circuit 200 sends a high-level power-off lock signal to the gate of the second NMOS transistor Q4, causing the second NMOS transistor Q4 to turn on and then pull the gate of the second PMOS transistor Q2 to ground, thereby turning on the second PMOS transistor Q2; then, a current provided by the external power supply V1 flows through the second PMOS transistor Q2 to the gate of the first NMOS transistor Q3, turning on the first NMOS transistor Q3. At this time, the gate of the second PMOS transistor Q2 is always pulled down to ground by the first NMOS transistor Q3, while the gate of the first NMOS transistor Q3 is always pulled high due to the conduction of the second PMOS transistor Q2, thus forming a self-locking circuit; further, another current provided by the external power supply V1 flows into the gate of the first PMOS transistor Q1, causing the first PMOS transistor Q1 to no longer meet the conduction condition and shut down the back-end power output, thereby realizing a self-locking protection mechanism.

[0045] The embodiments provided in the present application can, when an overcurrent or short circuit occurs in an electrical device, continuously prevent the power output control circuit from outputting the operating current to the electrical device through the self-locking protection control circuit, thereby cutting off the power supply to the electrical device, so that the self-locking power supply protection circuit can realize the current output self-locking function, thereby ensuring the effectiveness of the self-locking power supply protection circuit.

[0046] In an optional embodiment, if Figure 2 As shown, the self-locking power supply protection circuit 300 further includes a second light emitting diode D2.

[0047] Specifically, the anode terminal of the second light-emitting diode D2 is connected to the drain terminal of the second PMOS transistor Q2, and the cathode terminal of the second light-emitting diode D2 is grounded. Specifically, when an overcurrent or short circuit occurs in the electrical device, the second PMOS transistor Q2 turns on, allowing the external power supply V1 to output current to the anode terminal of the second light-emitting diode D2, causing the second light-emitting diode D2 to turn on and emit light. The embodiments provided herein can emit a light signal to indicate that the electrical device is in an abnormal current state when a short circuit or overcurrent occurs in the electrical device. This allows relevant personnel to intuitively observe the operation of the self-locking power supply protection circuit and the electrical device, thereby improving the functionality of the self-locking power supply protection circuit.

[0048] Furthermore, the self-locking power supply protection circuit may further include a second current protection resistor R4. The cathode terminal of the first light-emitting diode D1 and the cathode terminal of the second light-emitting diode D2 are connected in parallel to the first terminal of the second current protection resistor R4. The second terminal of the second current protection resistor R4 is grounded, so that the second current protection resistor R4 provides current protection for the first light-emitting diode D1 and the second light-emitting diode D2. Here, the second current protection resistor R4, the first light-emitting diode D1, and the second light-emitting diode D2 can form a status indication circuit for indicating the operating status of the self-locking power supply protection circuit.

[0049] In an optional embodiment, the power-off lock signal may be in the form of a high-level signal. Figure 2 As shown, the current detection circuit 200 includes a voltage comparator U1 , a first current detection resistor R5 , a second current detection resistor R6 , a third current detection resistor R7 and a pull-up resistor R8 .

[0050] Specifically, a first end of the first current detection resistor R5 is connected to the current input terminal, a second end of the first current detection resistor R5 is connected to the inverting input terminal of the voltage comparator U1 and the first end of the second current detection resistor R6, respectively, and a second end of the second current detection resistor R6 is grounded. Furthermore, a power input terminal of the voltage comparator U1 is connected to an external voltage source V2, and a ground terminal of the voltage comparator U1 is grounded.

[0051] Furthermore, the connection end after the first end of the third current detection resistor R7 is connected in parallel with the in-phase input end of the voltage comparator U1 is connected to the current output end of the electrical device 400 as the input end of the current detection circuit 200, and the second end of the third current detection resistor R7 is grounded.

[0052] Furthermore, the first end of the pull-up resistor R8 is connected to the external voltage source V2, and the connection end of the second end of the pull-up resistor R8 and the output end of the voltage comparator U1 in parallel is connected to the control end of the self-locking protection control circuit 300, for sending the power-off lock signal, wherein, when the voltage of the non-inverting input end of the voltage comparator U1 is greater than the voltage of the inverting input end, the current detection circuit 200 determines that the electrical device 400 is in an abnormal current state, and the current detection circuit 200 sends a power-off lock signal to the control end of the self-locking protection control circuit 300.

[0053] Furthermore, the current detection circuit 200 also includes a first current limiting resistor R9, the first end of the first current limiting resistor R9 is connected between the second end of the pull-up resistor R8 and the output end of the voltage comparator U1, and the second end of the first current limiting resistor R9 is connected to the control end of the self-locking protection control circuit 300 to play a current limiting role.

[0054] During actual operation, when the circuit of the electrical device 400 is normal and there is no overcurrent or short circuit, the voltage at the inverting input terminal of the voltage comparator U1 is higher than the voltage at the non-inverting input terminal. At this time, the voltage comparator U1 outputs a low level, and the current detection circuit 200 does not output a power-off lock signal to the self-locking protection control circuit 300.

[0055] Conversely, if an overcurrent or short circuit occurs in the circuit of the electrical device 400, the current flowing through the third current detection resistor R7 increases significantly, causing the voltage at the first terminal of the third current detection resistor R7 to increase significantly, while the voltage at the first terminal of the second current detection resistor R6 does not increase, causing the voltage at the non-inverting input terminal of the voltage comparator U1 to be higher than the voltage at the inverting input terminal. Furthermore, because the voltage at the inverting input terminal of the voltage comparator U1 is lower than the voltage at the non-inverting input terminal, the voltage comparator U1 outputs a high level. At this time, due to the pull-up resistor R8 connected to the output terminal of the voltage comparator U1, the output signal of the voltage comparator U1 is pulled up to a high level signal, thereby sending a power-off lock signal to the control terminal of the self-locking protection control circuit 300.

[0056] Furthermore, when designing the current detection circuit 200, a protection current value can be set for the current detection circuit 200 by adjusting the resistance values ​​of the first current detection resistor R5, the second current detection resistor R6, and the third current detection resistor R7. This allows the current detection circuit 200 to send a power-off lock signal to the control terminal of the self-locking protection control circuit 300 when the current detection circuit 200 detects that the current outputted by the current output terminal of the electrical device 400 is higher than the protection current value. Specifically, the specific formula for the protection current value can be shown in Formula 1:

[0057] I = V_IN*Rb / (Ra+Rb) / Rc (1)

[0058] Wherein, I is the protection current value, V_IN is the power voltage value output by the external power supply V1 connected to the power output control circuit 100, Ra is the resistance value of the first current detection resistor R5, Rb is the resistance value of the second current detection resistor R6, and Rc is the resistance value of the third current detection resistor R7.

[0059] Furthermore, based on formula 1 and Figure 2 Explanation: If Ra is 90 kilo-ohms, Rb is 2 kilo-ohms, and Rc is 0.1 ohms, when the circuit of the electrical device 400 is operating normally, the power output control circuit 100 outputs a working current, and the working current flows in two directions. One current flows to the two voltage-dividing resistors, the first current detection resistor R5 and the second current detection resistor R6. The voltage on this voltage-dividing resistor can be identified as the overcurrent protection threshold voltage. If the power supply voltage output by the external power supply V1 is 5V, the overcurrent protection threshold voltage is 0.1V, and the protection current value is 0.1V. / Rc, the other current flows to the rear-end electrical device 400. The working current flows to the electrical device 400 and then passes through the third current detection resistor R7 for current sampling before reaching the ground. Here, the protection current value is 0.1V / Rc=1A. Here, as long as the current output by the electrical device 400 is greater than 1A, the voltage across the third current detection resistor R7 will be greater than the voltage across the second current detection resistor R6, thereby making the voltage at the non-inverting input terminal of the voltage comparator U1 greater than the voltage at the inverting input terminal, thereby sending a power-off lock signal to the self-locking protection control circuit 300.

[0060] The embodiments provided in this application enable the current detection circuit to determine whether the electrical device is in an abnormal current state such as overcurrent or short circuit by monitoring the current output by the electrical device from the current output terminal, thereby improving the efficiency of the self-locking power supply protection circuit in detecting whether the electrical device is in an overcurrent or short circuit state. Furthermore, the protection current value can be set by adjusting the resistance values ​​of the first current detection resistor, the second current detection resistor, and the third current detection resistor. When the current value output by the electrical device from the current output terminal exceeds the protection current value, a power-off lock signal is sent to the self-locking protection control circuit 300, so that the power output control circuit continuously stops outputting the operating current to the electrical device, thereby improving the functionality of the self-locking power supply protection circuit.

[0061] In an optional embodiment, the first current detection resistor, the second current detection resistor, and the third current detection resistor can all be variable resistors. In the embodiments provided herein, the resistance values ​​of the first current detection resistor, the second current detection resistor, and the third current detection resistor can be changed to change the protection current value, thereby improving the operability of the self-locking power supply protection circuit.

[0062] In an optional embodiment, if Figure 2As shown, the self-locking power supply protection circuit further includes a self-locking reset switch K1.

[0063] Specifically, a first end of the self-latching reset switch K1 is connected to the gate of the first NMOS transistor Q3, and a second end of the self-latching reset switch K1 is grounded. The self-latching reset switch K1 can be controlled to be in an on state or an off state. When the self-latching reset switch K1 is in the on state, the gate of the first NMOS transistor Q3 is grounded, and when the self-latching reset switch K1 is in the off state, the gate of the first NMOS transistor Q3 is not grounded. In the initial state of the self-latching power supply protection circuit, the self-latching reset switch K1 is in the off state.

[0064] During actual operation, when an overcurrent or short circuit occurs in the circuit of the electrical device 400 and the self-locking protection control circuit 300 continuously outputs a power supply termination signal to the power output control circuit 100, it is only necessary to press the self-locking reset switch K1 to control the self-locking reset switch K1 to conduct, so that the gate of the first NMOS transistor Q3 is grounded through the self-locking reset switch K1, causing the gate of the first NMOS transistor Q3 to be at a low level, causing the first NMOS transistor Q3 to be non-conductive, thereby connecting the gate of the second PMOS transistor Q2 to the external power supply V1, causing the second PMOS transistor Q2 to also be non-conductive. In this way, the gate of the first PMOS transistor Q1 is again pulled down to ground through the pull-down resistor R1, turning on the first PMOS transistor Q1 and allowing the electrical device 400 to obtain an operating current. The embodiments provided herein can reset the self-locking power supply protection circuit through the self-locking reset switch, re-powering the electrical device, thereby improving the functionality of the self-locking power supply protection circuit.

[0065] On the other hand, an embodiment of the present invention provides a motherboard including the self-locking power supply protection circuit as described above.

[0066] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A self-locking power supply protection circuit for supplying power to electrical devices, characterized in that: The self-locking power supply protection circuit includes a power output control circuit, a current detection circuit and a self-locking protection control circuit; The output end of the power output control circuit is connected to the current input end of the electrical device, so as to supply power to the electrical device; The input end of the current detection circuit is connected to the current output end of the electrical device, and is used to collect the output current of the electrical device, determine whether the electrical device is in an abnormal current state based on the output current, and send a power-off locking signal to the control end of the self-locking protection control circuit when the electrical device is in the abnormal current state; The output end of the self-locking protection control circuit is connected to the control end of the power output control circuit, and is used to continuously output a power supply termination signal to the power output control circuit after receiving the power-off locking signal, so as to control the power output control circuit to terminate supplying power to the electrical device.

2. The self-locking power supply protection circuit according to claim 1, characterized in that: The power output control circuit includes a first PMOS transistor and a pull-down resistor; The source of the first PMOS transistor is connected to an external power supply, the drain of the first PMOS transistor is connected to the current input terminal of the power-consuming device, and the gate of the first PMOS transistor is connected to the output terminal of the self-locking protection control circuit for receiving the power supply termination signal; The gate of the first PMOS transistor is also grounded through the pull-down resistor.

3. The self-locking power supply protection circuit according to claim 2, characterized in that: The self-locking power supply protection circuit further includes a first light emitting diode; An anode terminal of the first light emitting diode is connected to a drain terminal of the first PMOS transistor, and a cathode terminal of the first light emitting diode is grounded.

4. The self-locking power supply protection circuit according to claim 1, characterized in that: The self-locking protection control circuit includes a second PMOS transistor, a first NMOS transistor and a second NMOS transistor; A connection end where the gate of the second PMOS transistor, the drain of the first NMOS transistor, and the drain of the second NMOS transistor are connected in parallel is connected to an external power supply, a source of the second PMOS transistor is connected to the external power supply, and a connection end where the source of the first NMOS transistor and the source of the second NMOS transistor are connected in parallel is grounded; The gate of the second NMOS transistor is connected to the current detection circuit as a control terminal of the self-locking protection control circuit, and is used to receive the power-off locking signal; The connection end after the gate of the first NMOS transistor and the drain of the second PMOS transistor are connected in parallel is connected to the control end of the power output control circuit as the output end of the self-locking protection control circuit, and is used to send the power supply termination signal.

5. The self-locking power supply protection circuit according to claim 4, characterized in that: The self-locking power supply protection circuit further includes a second light emitting diode; An anode terminal of the second light emitting diode is connected to the drain of the second PMOS transistor, and a cathode terminal of the second light emitting diode is grounded.

6. The self-locking power supply protection circuit according to claim 1, characterized in that: The current detection circuit includes a voltage comparator, a pull-up resistor, a first current detection resistor, a second current detection resistor and a third current detection resistor; A first end of the first current detection resistor is connected to the current input terminal of the electrical device, a second end of the first current detection resistor is connected to the inverting input terminal of the voltage comparator and the first end of the second current detection resistor respectively, and a second end of the second current detection resistor is grounded; The connection end of the first end of the third current detection resistor and the non-inverting input end of the voltage comparator connected in parallel is connected to the current output end of the electrical device as the input end of the current detection circuit, and the second end of the third current detection resistor is grounded; The first end of the pull-up resistor is connected to an external voltage source, and the connection end after the second end of the pull-up resistor is connected in parallel to the output end of the voltage comparator is connected to the control end of the self-locking protection control circuit, for sending the power-off locking signal, wherein when the voltage of the non-inverting input end of the voltage comparator is greater than the voltage of the inverting input end, the current detection circuit sends the power-off locking signal to the control end of the self-locking protection control circuit.

7. The self-locking power supply protection circuit according to claim 6, characterized in that: The first current detection resistor, the second current detection resistor, and the third current detection resistor are all variable resistors.

8. The self-locking power supply protection circuit according to claim 4, characterized in that: The self-locking protection control circuit also includes a current limiting resistor; The current limiting resistor is connected between a connection end where the gate of the second PMOS transistor, the drain of the first NMOS transistor, and the drain of the second NMOS transistor are connected in parallel and the external power supply.

9. The self-locking power supply protection circuit according to claim 4, characterized in that: The self-locking power supply protection circuit also includes a self-locking reset switch; A first end of the self-locking reset switch is connected to the gate of the first NMOS transistor, and a second end of the self-locking reset switch is grounded.

10. A motherboard, characterized in that: The invention comprises the self-locking power supply protection circuit according to any one of claims 1 to 9.

Images