Power failure protection and detection circuit

Abstract

The utility model discloses a power-down protection and detection circuit, which belongs to the technical field of master control system protection and comprises a power-down protection circuit used for protecting a master control board during sudden power-down; the detection feedback circuit is used for detecting whether the main control board is in a power-down state at present; the detection feedback circuit is connected with the power failure protection circuit; the utility model provides the protection circuit aiming at the power failure condition of the main control system, automatic protection and detection during sudden power failure can be realized, and a simple circuit is used as a detection circuit, so that the detection delay requirement can be met, and the use cost can be ensured.

Description

Technical Field

[0001] This utility model relates to the field of main control system protection technology, specifically a power failure protection and detection circuit. Background Technology

[0002] In today's environment where highly integrated industrial equipment is becoming mainstream, the stable operation of the main control circuit is a necessary condition for a device to maintain reliability in hazardous application scenarios. Power failure of the main control system will directly lead to equipment malfunction, and in severe cases, cause personal safety accidents.

[0003] Current power failure protection methods do not take into account the design of detection circuits, resulting in a certain delay, which may lead to a lag in receiving fault information and cause danger. Summary of the Invention

[0004] To address the problems of existing technologies, this utility model provides a power-off protection and detection circuit, comprising:

[0005] Power failure protection circuit, used to protect the main control board in the event of a sudden power failure;

[0006] The detection feedback circuit is used to detect whether the main control board is currently in a power-off state;

[0007] The detection feedback circuit is connected to the power-off protection circuit;

[0008] The detection feedback circuit includes: an operational amplifier and an NPN transistor;

[0009] The non-inverting input terminal of the operational amplifier is connected to the power supply port of the main control board, the inverting input terminal of the operational amplifier is connected to the power supply input port, and the output terminal of the operational amplifier is connected to the base of the NPN transistor.

[0010] The collector of the NPN transistor is connected to a 5V voltage, and the emitter of the NPN transistor is grounded.

[0011] Furthermore, the power-down protection circuit includes: a power supply input port, a main control board power supply port, a filter inductor, a power-down protection reverse diode, a voltage regulator capacitor, a supercapacitor, and a first resistor;

[0012] The filter inductor, the power-down protection reverse diode, the first resistor, the supercapacitor, and the power supply input port are connected in series to form a circuit, and the circuit is grounded.

[0013] A common diode is connected in parallel across the first resistor, and a Zener diode is connected in parallel across the supercapacitor.

[0014] The power supply port of the hollow board is electrically connected to the power failure protection anti-reverse diode and the first resistor.

[0015] The voltage-stabilizing capacitor is connected in parallel in the circuit.

[0016] Furthermore, the supercapacitor includes: a fourth supercapacitor, a fifth supercapacitor, and a sixth supercapacitor;

[0017] The fourth supercapacitor, the fifth supercapacitor, and the sixth supercapacitor are connected in series in this circuit.

[0018] The fourth, fifth, and sixth supercapacitors are connected in parallel with a first Zener diode, a second Zener diode, and a third Zener diode, respectively.

[0019] Furthermore, the voltage-stabilizing capacitor includes: a first voltage-stabilizing capacitor, a second voltage-stabilizing capacitor, and a third voltage-stabilizing capacitor;

[0020] The first voltage-stabilizing capacitor, the filter inductor, the power-down protection reverse diode, the first resistor, the fourth supercapacitor, the fifth supercapacitor, and the sixth supercapacitor are connected in series to form a circuit;

[0021] The two ends of the first voltage-stabilizing capacitor are connected in parallel with the power supply input port;

[0022] The second voltage-stabilizing capacitor is connected in parallel across the first voltage-stabilizing capacitor;

[0023] The third voltage-stabilizing capacitor is connected in parallel across the second voltage-stabilizing capacitor;

[0024] The filter inductor is located on the line between the first voltage-stabilizing capacitor and the second voltage-stabilizing capacitor;

[0025] The power-down protection anti-reverse diode is located on the line between the second voltage-stabilizing capacitor and the third voltage-stabilizing capacitor;

[0026] The main control board power supply port is located on the line between the power-down protection anti-reverse diode and the third voltage regulator capacitor.

[0027] Furthermore, a third resistor is provided between the non-inverting input terminal of the operational amplifier and the power supply port of the main control board, a second resistor is provided between the inverting input terminal of the operational amplifier and the power supply input port, a fourth resistor is connected in parallel between the second resistor and the output terminal of the operational amplifier, a branch is led out from the line between the second resistor and the non-inverting input terminal of the operational amplifier, a fifth resistor is connected on the branch, and the fifth resistor is grounded;

[0028] A sixth resistor is provided between the output terminal of the operational amplifier and the base of the NPN transistor. A seventh resistor is connected in parallel between the sixth resistor, the base of the NPN transistor, and the emitter of the NPN transistor. The collector of the NPN transistor is connected to the voltage 5V through an eighth resistor.

[0029] The beneficial effects of this utility model are:

[0030] This application provides a protection circuit for the main control system in the event of a power failure. It can realize automatic protection and detection in the event of a sudden power failure. The detection circuit uses a simple circuit, which can meet the detection delay requirements and ensure the cost of use.

[0031] Power is supplied by energy storage capacitors, serving as backup power in case of power failure, maintaining protection capability at the second level. Power is supplied by protection capacitors as the power source for the detection circuit, ensuring normal operation of the detection circuit even in the event of a complete power failure. The introduction of anti-reverse diodes ensures that it can only be used in the event of power failure, reducing circuit losses. The introduction of Zener diodes balances the voltage, extending the service life of the protection capacitors. The introduction of cement resistors slows down the capacitor charging time, reduces stress risk, and ensures normal operation. Attached Figure Description

[0032] Figure 1 A schematic diagram of the power-off protection circuit provided by this utility model;

[0033] Figure 2 A schematic diagram of the detection feedback circuit provided by this utility model.

[0034] Figure label:

[0035] In the diagram: 1 is the power input port, 2 is the main control board power supply port, 3 is the filter inductor, 4 is the reverse protection diode for power loss, 5 is the first resistor, 6 is a general diode, 7 is the fourth supercapacitor, 8 is the fifth supercapacitor, 9 is the sixth supercapacitor, 10 is the first Zener diode, 11 is the second Zener diode, 12 is the third Zener diode, 13 is the first Zener capacitor, 14 is the second Zener capacitor, 15 is the third Zener capacitor, 16 is the operational amplifier, 17 is the NPN transistor, 18 is the second resistor, 19 is the third resistor, 20 is the fourth resistor, 21 is the fifth resistor, 22 is the sixth resistor, 23 is the seventh resistor, and 24 is the eighth resistor. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] Please see Figure 1-2 This utility model provides a power failure protection and detection circuit, including:

[0038] Power failure protection circuit, used to protect the main control board in the event of a sudden power failure;

[0039] The detection feedback circuit is used to detect whether the main control board is currently in a power-off state;

[0040] The detection feedback circuit is connected to the power failure protection circuit.

[0041] The power-down protection circuit includes: power input port 1, main control board power supply port 2, filter inductor 3, power-down protection anti-reverse diode 4, voltage regulator capacitor, supercapacitor and first resistor 5;

[0042] The filter inductor 3, the power-down protection anti-reverse diode 4, the first resistor 5, the voltage stabilizing capacitor and the supercapacitor are connected in series to form a circuit, which is connected to the power supply input port 1 and grounded.

[0043] A common diode 6 is connected in parallel across the first resistor 5, and a Zener diode is connected in parallel across the supercapacitor.

[0044] The power supply port of the hollow board is electrically connected to the power failure protection diode 4 and the first resistor 5.

[0045] The supercapacitors include: a fourth supercapacitor 7, a fifth supercapacitor 8, and a sixth supercapacitor 9;

[0046] The fourth supercapacitor 7, the fifth supercapacitor 8, and the sixth supercapacitor 9 are connected in series in this circuit;

[0047] The first Zener diode 10, the second Zener diode 11, and the third Zener diode 12 are connected in parallel across the two ends of the fourth supercapacitor 7, the fifth supercapacitor 8, and the sixth supercapacitor 9, respectively.

[0048] The voltage stabilizing capacitor includes: a first voltage stabilizing capacitor 13, a second voltage stabilizing capacitor 14 and a third voltage stabilizing capacitor 15;

[0049] The first voltage regulator capacitor 13, the filter inductor 3, the power-down protection reverse diode 4, the first resistor 5, the fourth supercapacitor 7, the fifth supercapacitor 8 and the sixth supercapacitor 9 are connected in series to form a circuit;

[0050] The two ends of the first voltage-stabilizing capacitor 13 are connected in parallel with the power supply input port 1;

[0051] The second voltage regulator capacitor 14 is connected in parallel across the first voltage regulator capacitor 13;

[0052] The third voltage-stabilizing capacitor 15 is connected in parallel across the second voltage-stabilizing capacitor 14;

[0053] The filter inductor 3 is located on the line between the first voltage-stabilizing capacitor 13 and the second voltage-stabilizing capacitor 14;

[0054] The power-down protection anti-reverse diode 4 is located on the line between the second voltage-stabilizing capacitor 14 and the third voltage-stabilizing capacitor 15.

[0055] The main control board power supply port 2 is located on the line between the power-down protection anti-reverse diode 4 and the third voltage regulator capacitor 15.

[0056] The power failure protection circuit works as follows: The main control system typically operates at a power supply voltage of 24V and has an internal level conversion circuit. For a white-box system, the developer can roughly estimate the overall operating power consumption and the minimum voltage required to maintain the function. The capacitance value of the supercapacitor that can maintain operation for seconds in the event of a sudden power failure can be obtained through the capacitor discharge formula.

[0057] When the system boots up normally, the main control board is powered by the power input port. At this time, the power supply voltage is transmitted to the main control board's power supply port through the reverse protection diode for power-down protection, powering the main control board. Simultaneously, it charges the fourth, fifth, and sixth supercapacitors through the first resistor (a cement resistor). The current flow is: power input port - filter inductor - reverse protection diode for power-down protection - first resistor - fourth supercapacitor - fifth supercapacitor - sixth supercapacitor. During this process, the main control board's power supply port gradually stabilizes from a low level to the operating voltage. After charging is complete, the supercapacitors will stop charging, and the voltage distribution of each series-connected supercapacitor will be maintained uniformly due to the voltage equalization effect of the first, second, and third Zener diodes, preventing severe bias that could shorten the capacitor's lifespan.

[0058] In the event of a sudden power outage, the input voltage at the power supply input port suddenly drops to 0. At this time, the energy stored in the supercapacitor will be gradually released. Due to the presence of the reverse protection diode for power outage protection, the energy output by the capacitor will only supply the power supply port of the main control board as the energy for the operation of the main control system. At this time, the current direction is from the sixth supercapacitor to the fifth supercapacitor, then to the fourth supercapacitor, and finally to the ordinary diode. It will not pass through the first resistor, thereby reducing losses and extending the protection time.

[0059] The detection feedback circuit includes: an operational amplifier 16 and an NPN transistor 17;

[0060] The non-inverting input terminal of the operational amplifier 16 is connected to the power supply port 2 of the main control board, the inverting input terminal of the operational amplifier 16 is connected to the power supply input port 1, and the output terminal of the operational amplifier 16 is connected to the base of the NPN transistor 17.

[0061] The collector of the NPN transistor 17 is connected to a 5V voltage, and the emitter of the NPN transistor 17 is grounded.

[0062] A third resistor 19 is provided between the non-inverting input terminal of the operational amplifier 16 and the power supply port 2 of the main control board. A second resistor 18 is provided between the inverting input terminal of the operational amplifier 16 and the power supply input port 1. A fourth resistor 20 is connected in parallel between the second resistor 18 and the output terminal of the operational amplifier 16. A branch is led out from the line between the second resistor 18 and the non-inverting input terminal of the operational amplifier 16, and a fifth resistor 21 is connected on the branch. The fifth resistor 21 is grounded.

[0063] A sixth resistor 22 is provided between the output terminal of the operational amplifier 16 and the base of the NPN transistor 17. A seventh resistor 23 is connected in parallel between the sixth resistor 22, the base of the NPN transistor 17, and the emitter of the NPN transistor 17. The collector of the NPN transistor 17 is connected to the voltage 5V through an eighth resistor 24.

[0064] To ensure that the operational amplifier circuit can function normally during power loss, Figure 2 The operational amplifier and 5V power supply are both obtained by level conversion from the power supply port of the main control board.

[0065] The operating principle of the detection circuit is as follows:

[0066] When the device is powered on, the input voltage at the power supply input port is greater than the output voltage at the main control board power supply port, and the operational amplifier's power supply voltage cannot meet the normal operation of the operational amplifier at this time. During the charging process, the power supply input port gradually rises to the operating voltage. At this time, the operational amplifier's output voltage is (main control board power supply port - power supply input port * fourth resistor / second resistor) < transistor conduction voltage. The feedback signal outputs a 5V high level, indicating that the power failure has not occurred.

[0067] When a fault occurs, the system suddenly loses power, that is, the power supply input port drops to 0V. The operational amplifier output voltage can turn on the NPN transistor. At this time, the feedback signal is pulled low to a low level. The system detects the change in the feedback signal and sends a blocking command to complete the power failure protection and reduce the risk of damage.

[0068] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A power-off protection and detection circuit, characterized in that, include: Power failure protection circuit, used to protect the main control board in the event of a sudden power failure; The detection feedback circuit is used to detect whether the main control board is currently in a power-off state; The detection feedback circuit is connected to the power-off protection circuit; The detection feedback circuit includes: an operational amplifier and an NPN transistor; The non-inverting input terminal of the operational amplifier is connected to the power supply port of the main control board, the inverting input terminal of the operational amplifier is connected to the power supply input port, and the output terminal of the operational amplifier is connected to the base of the NPN transistor. The collector of the NPN transistor is connected to a 5V voltage, and the emitter of the NPN transistor is grounded.

2. The power failure protection and detection circuit according to claim 1, characterized in that, The power-down protection circuit includes: a power supply input port, a main control board power supply port, a filter inductor, a power-down protection reverse diode, a voltage regulator capacitor, a supercapacitor, and a first resistor; The filter inductor, the power-down protection reverse diode, the first resistor, the supercapacitor, and the power supply input port are connected in series to form a circuit, and the circuit is grounded. A common diode is connected in parallel across the first resistor, and a Zener diode is connected in parallel across the supercapacitor. The main control board power supply port is electrically connected to the power-down protection anti-reverse diode and the first resistor. The voltage-stabilizing capacitor is connected in parallel in the circuit.

3. The power failure protection and detection circuit according to claim 2, characterized in that, The supercapacitors include: a fourth supercapacitor, a fifth supercapacitor, and a sixth supercapacitor; The fourth supercapacitor, the fifth supercapacitor, and the sixth supercapacitor are connected in series in this circuit. The fourth, fifth, and sixth supercapacitors are connected in parallel with a first Zener diode, a second Zener diode, and a third Zener diode, respectively.

4. The power failure protection and detection circuit according to claim 3, characterized in that, The voltage-regulating capacitor includes: a first voltage-regulating capacitor, a second voltage-regulating capacitor, and a third voltage-regulating capacitor; The first voltage-stabilizing capacitor, the filter inductor, the power-down protection reverse diode, the first resistor, the fourth supercapacitor, the fifth supercapacitor, and the sixth supercapacitor are connected in series to form a circuit; The two ends of the first voltage-stabilizing capacitor are connected in parallel with the power supply input port; The second voltage-stabilizing capacitor is connected in parallel across the first voltage-stabilizing capacitor; The third voltage-stabilizing capacitor is connected in parallel across the second voltage-stabilizing capacitor; The filter inductor is located on the line between the first voltage-stabilizing capacitor and the second voltage-stabilizing capacitor; The power-down protection anti-reverse diode is located on the line between the second voltage-stabilizing capacitor and the third voltage-stabilizing capacitor; The main control board power supply port is located on the line between the power-down protection anti-reverse diode and the third voltage regulator capacitor.

5. The power failure protection and detection circuit according to claim 2, characterized in that, A third resistor is provided between the non-inverting input terminal of the operational amplifier and the power supply port of the main control board. A second resistor is provided between the inverting input terminal of the operational amplifier and the power supply input port. A fourth resistor is connected in parallel between the second resistor and the output terminal of the operational amplifier. A branch is led out from the line between the second resistor and the non-inverting input terminal of the operational amplifier. A fifth resistor is connected to the branch and the fifth resistor is grounded. A sixth resistor is provided between the output terminal of the operational amplifier and the base of the NPN transistor. A seventh resistor is connected in parallel between the sixth resistor, the base of the NPN transistor, and the emitter of the NPN transistor. The collector of the NPN transistor is connected to the voltage 5V through an eighth resistor.

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