Delay protection circuit, switching power supply and motor control device

Abstract

The invention relates to a delay protection circuit, a switching power supply and a motor control device. In the circuit, a signal input circuit is connected with a control chip and an input power supply; the signal input circuit obtains a control signal transmitted by the control chip and controls the input power supply to transmit an input signal according to the control signal; the signal conversion circuit is connected with the signal input circuit, and the signal conversion circuit obtains an input signal and performs conversion processing on the input signal to obtain a first conversion signal; the integral trigger circuit is connected with the signal conversion circuit, the integral trigger circuit is connected with the load module, the integral trigger circuit acquires a first conversion signal, performs integral accumulation processing on the first conversion signal to obtain an accumulation signal, and triggers the load module to perform overload protection when the accumulation signal meets a preset condition; the delay overload protection is triggered in an integral energy accumulation mode, a high-capacity capacitor does not need to be adopted, the circuit cost is reduced, the circuit size is reduced, and the circuit reliability is enhanced.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a time-delay protection circuit, a switching power supply and a motor control device. Background Art

[0002] Delay circuits can effectively protect electrical equipment from damage caused by sudden power on or off. For example, in motor control, delay circuits can ensure that the motor has enough time to reach a stable state when starting, thereby reducing mechanical wear and failure.

[0003] At present, RC circuits are usually used as delay circuits. However, in existing RC circuits, when a longer delay time is required, a larger capacitor device needs to be used, resulting in a larger delay circuit. The capacitor discharge requires a longer time to reset or an additional discharge control circuit is added to discharge the capacitor, resulting in increased costs and easy damage to internal components of the circuit, affecting the reliability of the delay circuit. Summary of the invention

[0004] Based on this, it is necessary to provide a delay protection circuit, a switching power supply and a motor control device that can reduce costs, reduce circuit volume and enhance circuit reliability in order to address the problems existing in the above-mentioned existing delay circuits.

[0005] In a first aspect, the present application provides a delay protection circuit, comprising:

[0006] A signal input circuit, the signal input circuit is used to connect the control chip and the input power supply; the signal input circuit is configured to obtain the control signal transmitted by the control chip, and control the input power supply to transmit the input signal according to the control signal;

[0007] A signal conversion circuit, the signal conversion circuit is connected to the signal input circuit, and the signal conversion circuit is configured to obtain an input signal and perform conversion processing on the input signal to obtain a first conversion signal;

[0008] The integral trigger circuit is connected to the signal conversion circuit. The integral trigger circuit is used to connect the load module. The integral trigger circuit is configured to obtain a first conversion signal, perform integral accumulation processing on the first conversion signal to obtain an accumulated signal, and when the accumulated signal meets a preset condition, trigger the load module to perform overload protection.

[0009] In one of the embodiments, the integral trigger circuit is further configured to, when the voltage amplitude of the first conversion signal is greater than the first voltage threshold, perform an integral comparison operation on the voltage amplitude of the first conversion signal and the first voltage threshold to obtain a cumulative signal; when the voltage amplitude of the cumulative signal is less than the second voltage threshold, trigger the load module to perform overload protection.

[0010] In one embodiment, the integration trigger circuit includes an integration accumulation circuit and a trigger circuit;

[0011] The integral accumulation circuit is connected between the trigger circuit and the signal conversion circuit, and the trigger circuit is connected to the load module.

[0012] In one embodiment, the integral accumulation circuit includes a first resistor, a second resistor, a first capacitor, a second capacitor, a first diode and a first operational amplifier;

[0013] A first end of the first resistor is connected to the signal conversion circuit, a second end of the first resistor is connected to the negative input end of the first operational amplifier, and a positive input end of the first operational amplifier is used to access a voltage signal corresponding to a first voltage threshold;

[0014] The first end of the first capacitor is connected to the second end of the first resistor, and the second end of the first capacitor is connected to the output end of the first operational amplifier; the cathode of the first diode is connected to the output end of the first operational amplifier, the anode of the first diode is connected to the first end of the second resistor, the first end of the second resistor is connected to the trigger circuit, the second end of the second resistor is connected to the power supply, the first end of the second capacitor is connected to the power supply, and the second end of the second capacitor is connected to the ground wire; the power supply end of the first operational amplifier is connected to the power supply, and the ground end of the first operational amplifier is connected to the ground wire.

[0015] In one embodiment, the trigger circuit includes a third resistor, a first switch tube and a first comparator;

[0016] The negative input terminal of the first comparator is connected to the integral accumulation circuit, the positive input terminal of the first comparator is used to access the voltage signal corresponding to the second voltage threshold, and the output terminal of the first comparator is connected to the first end of the third resistor; the second end of the third resistor is connected to the gate of the first switching tube, the source of the first switching tube is connected to the ground wire, and the drain of the first switching tube is connected to the negative module.

[0017] In one embodiment, the signal input circuit includes a transformer, a second switch tube and a primary winding of a current transformer;

[0018] The primary end of the transformer is used to connect to the input power supply, the secondary end of the transformer is connected to the first end of the primary winding of the current transformer, the second end of the primary winding of the current transformer is connected to the drain of the second switch tube, the source of the second switch tube is connected to the ground wire, and the gate of the second switch tube is used to connect to the control chip.

[0019] In one embodiment, the signal input circuit includes a fourth resistor and a fifth resistor;

[0020] A first end of the fourth resistor is connected to the source of the second switch tube, a second end of the fourth resistor is connected to the gate of the second switch tube, a first end of the fifth resistor is connected to the gate of the second switch tube, and a second end of the fifth resistor is connected to the control chip.

[0021] In one of the embodiments, the signal conversion circuit includes a rectifier module and a secondary winding of a current transformer;

[0022] The rectifier module is connected between the integral trigger circuit and the secondary winding of the current transformer, and the secondary winding of the current transformer is matched with the primary winding of the current transformer.

[0023] In one embodiment, the rectifier module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a fourth capacitor, a second diode and a third diode;

[0024] The first end of the sixth resistor is connected to the first end of the secondary winding of the current transformer, the second end of the sixth resistor is connected to the second end of the secondary winding of the current transformer, and the second end of the secondary winding of the current transformer is connected to the ground wire; the anode of the second diode is connected to the first end of the sixth resistor, the cathode of the second diode is connected to the first end of the seventh resistor, and the second end of the seventh resistor is connected to the second end of the sixth resistor;

[0025] The first end of the eighth resistor is connected to the cathode of the second diode, the second end of the eighth resistor is connected to the anode of the third diode, the first end of the third capacitor is connected to the second end of the eighth resistor, and the second end of the third capacitor is connected to the second end of the sixth resistor; the cathode of the third diode is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the second end of the sixth resistor, the first end of the ninth resistor is respectively connected to the first end of the fourth capacitor and the integration trigger circuit, and the second end of the ninth resistor is connected to the second end of the sixth resistor.

[0026] In a second aspect, the present application provides a switching power supply, comprising a delay protection circuit as described in any one of the above items.

[0027] In a third aspect, the present application provides a motor control device, comprising a switching power supply as described above.

[0028] One of the above technical solutions has the following advantages and beneficial effects:

[0029] The above-mentioned delay protection circuit includes a signal input circuit, a signal conversion circuit and an integral trigger circuit. The signal input circuit is used to connect the control chip and the input power supply; the signal input circuit is configured to obtain the control signal transmitted by the control chip, and control the input power supply to transmit the input signal according to the control signal; the signal conversion circuit is connected to the signal input circuit, and the signal conversion circuit is configured to obtain the input signal, and convert the input signal to obtain a first conversion signal; the integral trigger circuit is connected to the signal conversion circuit, and the integral trigger circuit is used to connect the load module, and the integral trigger circuit is configured to obtain the first conversion signal, integrate and accumulate the first conversion signal to obtain the accumulated signal, and when the accumulated signal meets the preset conditions, the load module is triggered to perform overload protection, thereby realizing reliable and safe triggering delay protection for the load module. The present application integrates and accumulates the input electrical signal. When the input load is heavier, the trigger delay protection time is shorter, thereby better protecting the power devices inside the power supply. When the output load is lighter, the delay trigger time is longer, allowing a longer overload period. The application realizes triggering delayed overload protection by integrating and accumulating energy, and there is no need to use large-capacity capacitors, thereby reducing circuit cost, reducing circuit size, and enhancing circuit reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A first structural schematic diagram of a delay protection circuit in one embodiment;

[0031] Figure 2 A second structural schematic diagram of a delay protection circuit in one embodiment;

[0032] Figure 3 FIG. 3 is a third structural diagram of a delay protection circuit in an embodiment.

[0033] Reference numerals:

[0034] 10. Signal input circuit; 20. Signal conversion circuit; 210. Rectification module; 30. Integral trigger circuit; 310. Integral accumulation circuit; 320. Trigger circuit; 40. Control chip; 50. Input power supply; 60. Load module;

[0035] R1, the first resistor; R2, the second resistor; R3, the third resistor; R4, the fourth resistor; R5, the fifth resistor; R6, the sixth resistor; R7, the seventh resistor; R8, the eighth resistor; R9, the ninth resistor; C1, the first capacitor; C2, the second capacitor; C3, the third capacitor; C4, the fourth capacitor; D1, the first diode; D2, the second diode; D3, the third diode; Q1, the first switch tube; Q2, the second switch tube; U1, the first operational amplifier; U2, the first comparator; T1, the transformer; L1, the current transformer. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] In addition, the term "plurality" shall mean two or more.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] In one embodiment, Figure 1 As shown, a delay protection circuit is provided, which includes a signal input circuit 10, a signal conversion circuit 20 and an integral trigger circuit 30. The signal input circuit 10 is used to connect the control chip 40 and the input power supply 50; the signal input circuit 10 is configured to obtain the control signal transmitted by the control chip 40, and control the input power supply 50 to transmit the input signal according to the control signal; the signal conversion circuit 20 is connected to the signal input circuit 10, and the signal conversion circuit 20 is configured to obtain the input signal, and convert the input signal to obtain a first conversion signal; the integral trigger circuit 30 is connected to the signal conversion circuit 20, and the integral trigger circuit 30 is used to connect the load module 60, and the integral trigger circuit 30 is configured to obtain the first conversion signal, integrate and accumulate the first conversion signal to obtain the accumulated signal, and when the accumulated signal meets the preset conditions, trigger the load module 60 to perform overload protection.

[0041] The control chip 40 may be a switching power supply chip, and the control chip 40 may be used to increase the PWM signal to the signal input circuit 10 to perform high-frequency switching control on the signal input circuit 10. The input power supply 50 refers to a power supply that increases the load current to the load module 60. The load module 60 may be a motor, for example, the load may be a motor applied to an electric door, the input power supply 50 provides the load current to the motor, and the motor provides the steering torque to the door.

[0042] Based on the control chip 40 connected to the signal input circuit 10, the control chip 40 can transmit a control signal to the signal input circuit 10, and the signal input circuit 10 obtains the corresponding control signal; based on the input power supply 50 connected to the signal input circuit 10, the signal input circuit 10 can control the input power supply 50 to transmit the input signal to the signal conversion module according to the control signal. Exemplarily, the input signal can be a triangular wave switching current signal.

[0043] The signal conversion circuit 20 can be used to convert the input signal transmitted by the signal input circuit 10, and then obtain a first conversion signal. The first conversion signal can be a DC signal. For example, based on the signal conversion circuit 20 connecting the integration trigger circuit 30, the signal conversion circuit 20 performs rectification and conversion processing on the received input signal, and then obtains a first conversion signal corresponding to the DC. It should be noted that the signal conversion circuit 20 can also filter the input signal to obtain a reliable and accurate first conversion signal, so that the integration trigger circuit 30 can process the first conversion signal.

[0044] The integral trigger circuit 30 is used to integrate and accumulate the first conversion signal transmitted by the signal conversion circuit 20, and compare the accumulated signal with the preset condition. When the accumulated signal meets the preset condition, a trigger signal is output, and then the load module 60 performs overload protection according to the trigger signal. For example, the trigger signal can be a high-level signal.

[0045] Based on the integration trigger circuit 30 connected between the signal conversion circuit 20 and the load module 60, the first conversion signal is integrated and accumulated, and it is determined whether to trigger the protection of the load module 60 according to whether the accumulated signal meets the preset conditions, so as to achieve that when the load current reaches the set protection threshold, the protection cannot be triggered immediately, but the delay protection time is different according to the load exceeding the set value. For example, the more the load current exceeds the set protection threshold, the shorter the delay protection time; the less the load current exceeds the set protection threshold, the longer the delay protection time, and then when the overload is not much, the power supply will not be protected quickly, and the overload can be allowed for a period of time; but when the overload is too much, the protection can be triggered quickly, thereby improving the reliability and safety of the circuit.

[0046] In the above-mentioned embodiment, the control chip 40 and the input power supply 50 are connected based on the signal input circuit 10; the signal input circuit 10 is configured to obtain the control signal transmitted by the control chip 40, and according to the control signal, control the input power supply 50 to transmit the input signal; the signal conversion circuit 20 is connected to the signal input circuit 10, and the signal conversion circuit 20 is configured to obtain the input signal, and convert the input signal to obtain a first conversion signal; the integral trigger circuit 30 is connected to the signal conversion circuit 20, and the integral trigger circuit 30 is used to connect the load module 60, and the integral trigger circuit 30 is configured to obtain the first conversion signal, integrate and accumulate the first conversion signal to obtain the accumulated signal, and when the accumulated signal meets the preset conditions, trigger the load module 60 to perform overload protection, thereby realizing reliable and safe triggering delay protection of the load module 60. The present application integrates and accumulates the input electrical signal. When the input load is heavier, the trigger delay protection time is shorter, thereby better protecting the power devices inside the power supply. When the output load is lighter, the delay trigger time is longer, allowing a longer overload period. The application realizes triggering delayed overload protection by integrating and accumulating energy, and there is no need to use large-capacity capacitors, thereby reducing circuit cost, reducing circuit size, and enhancing circuit reliability.

[0047] In one embodiment, the integral trigger circuit 30 is also configured to perform an integral comparison operation on the voltage amplitude of the first conversion signal and the first voltage threshold to obtain a cumulative signal when the voltage amplitude of the first conversion signal is greater than the first voltage threshold; and to trigger the load module 60 to perform overload protection when the voltage amplitude of the cumulative signal is less than the second voltage threshold.

[0048] Among them, the first voltage threshold can be obtained according to system preset; the second voltage threshold can be obtained according to system preset.

[0049] For example, the integral trigger circuit 30 can perform an integral comparison operation on the first conversion signal transmitted by the signal conversion circuit 20 and the voltage signal corresponding to the first voltage threshold. When the voltage amplitude of the first conversion signal is greater than the first voltage threshold, the voltage amplitude of the output cumulative signal begins to be gradually lowered. The greater the voltage difference between the voltage amplitude of the first conversion signal and the first voltage threshold, the faster the voltage amplitude of the cumulative signal decreases; the smaller the voltage difference between the voltage amplitude of the first conversion signal and the first voltage threshold, the slower the voltage amplitude of the cumulative signal decreases.

[0050] The integral trigger circuit 30 also compares the voltage amplitude of the accumulated signal with the second voltage threshold, and when the voltage amplitude of the accumulated signal is less than the second voltage threshold, outputs a high level signal to the load module 60, thereby triggering the load module 60 to perform overload protection.

[0051] It should be noted that if the voltage difference between the voltage amplitude of the first conversion signal and the first voltage threshold is larger, the voltage amplitude of the accumulated signal decreases faster, and the voltage amplitude of the accumulated signal is smaller than the second voltage threshold faster, which makes the output load module 60 of the integral trigger circuit 30 generate a high level for triggering protection earlier. If the voltage difference between the voltage amplitude of the first conversion signal and the first voltage threshold is smaller, the voltage amplitude of the accumulated signal decreases slower, and the voltage amplitude of the accumulated signal is smaller than the second voltage threshold slower, which makes the output load module 60 of the integral trigger circuit 30 generate a high level for triggering protection later, so that when the current (i.e., load current) entering the signal input circuit 10 is larger, the load module 60 is triggered for protection sooner, and when the current (i.e., load current) entering the signal input circuit 10 is smaller, the load module 60 is triggered for protection later, thereby enhancing the reliability and safety of the circuit.

[0052] Exemplarily, the load module 60 is an electric motor. When the motor is used on an electric door, delayed overload protection is performed through the integral accumulation method of the above embodiment, so that when the input power supply 50 is used to drive the motor, the motor will not be unable to start due to the large current required at the moment of starting, because the accumulated energy of the motor pulling the load will not reach the amount to trigger the protection; in addition, when the motor is stalled, protection can also be performed quickly, thereby removing the steering force of the motor itself and preventing the electric door from pinching people or animals.

[0053] In one embodiment, Figure 2 As shown, the integral trigger circuit 30 includes an integral accumulation circuit 310 and a trigger circuit 320 ; the integral accumulation circuit 310 is connected between the trigger circuit 320 and the signal conversion circuit 20 , and the trigger circuit 320 is connected to the load module 60 .

[0054] Among them, the integral accumulation circuit 310 is used to receive the first conversion signal transmitted by the signal conversion circuit 20, and the integral accumulation circuit 310 is also used to receive the voltage signal corresponding to the first voltage threshold. The integral accumulation circuit 310 can perform integral comparison operation processing on the first conversion signal and the voltage signal corresponding to the first voltage threshold, and then accumulate the signal. The trigger circuit 320 is used to receive the accumulated signal, and the trigger circuit 320 is also used to receive the voltage signal corresponding to the second voltage threshold. The trigger circuit 320 compares the accumulated signal with the voltage signal corresponding to the second voltage threshold, and determines whether to trigger the load module 60 for overload protection based on the processing result, thereby realizing reliable and safe delay protection.

[0055] In one example, if Figure 3As shown, the integral accumulation circuit 310 includes a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2, a first diode D1 and a first operational amplifier U1; the first end of the first resistor R1 is connected to the signal conversion circuit 20, the second end of the first resistor R1 is connected to the negative input end of the first operational amplifier U1, and the positive input end of the first operational amplifier U1 is used to access the voltage signal corresponding to the first voltage threshold; the first end of the first capacitor C1 is connected to the second end of the first resistor R1, and the second end of the first capacitor C1 is connected to the output end of the first operational amplifier U1; the cathode of the first diode D1 is connected to the output end of the first operational amplifier U1, the anode of the first diode D1 is connected to the first end of the second resistor R2, the first end of the second resistor R2 is connected to the trigger circuit 320, the second end of the second resistor R2 is connected to the power supply, the first end of the second capacitor C2 is connected to the power supply, and the second end of the second capacitor C2 is connected to the ground line; the power supply end of the first operational amplifier U1 is connected to the power supply, and the ground end of the first operational amplifier U1 is connected to the ground line.

[0056] The first capacitor C1 and the second capacitor C2 may be chip capacitors.

[0057] An integration and accumulation circuit 310 is composed of a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2, a first diode D1 and a first operational amplifier U1. The first conversion signal output by the signal conversion circuit 20 enters the negative input terminal of the first operational amplifier U1 after passing through the first resistor R1, and the voltage signal corresponding to the first voltage threshold is connected to the positive input terminal of the first operational amplifier U1. By performing integration and comparison operations on the first conversion signal and the voltage signal corresponding to the first voltage threshold, when the voltage amplitude of the first conversion signal is greater than the first voltage threshold, the voltage amplitude of the output voltage signal (i.e., the accumulation signal) at the anode end of the first diode D1 begins to be gradually lowered. It should be noted that the greater the difference between the voltage amplitude of the first conversion signal and the first voltage threshold, the faster the voltage amplitude of the output voltage signal decreases; the smaller the difference between the voltage amplitude of the first conversion signal and the first voltage threshold, the slower the voltage amplitude of the output voltage signal decreases, thereby being able to trigger delayed overload protection by integrating accumulated energy, without the need to use large-capacity capacitors or additionally setting up a discharge reset module to discharge and reset the corresponding capacitors, thereby reducing circuit costs, reducing circuit volume, and enhancing circuit reliability.

[0058] In one example, if Figure 3As shown, the trigger circuit 320 includes a third resistor R3, a first switch tube Q1 and a first comparator U2; the negative input terminal of the first comparator U2 is connected to the integral accumulation circuit 310, the positive input terminal of the first comparator U2 is used to access the voltage signal corresponding to the second voltage threshold, and the output terminal of the first comparator U2 is connected to the first end of the third resistor R3; the second end of the third resistor R3 is connected to the gate of the first switch tube Q1, the source of the first switch tube Q1 is connected to the ground wire, and the drain of the first switch tube Q1 is connected to the negative module.

[0059] The accumulated signal output by the integral accumulation circuit 310 enters the negative input terminal of the first comparator U2, and the voltage signal corresponding to the second voltage threshold is connected to the positive input terminal of the first comparator U2. By comparing and processing the accumulated signal and the voltage signal corresponding to the second voltage threshold, when the voltage amplitude of the accumulated signal output by the integral accumulation circuit 310 is pulled down to be less than the second voltage amplitude, the first comparator U2 outputs a high level, thereby driving the first switch tube Q1 to trigger the load module 60 to generate overload protection.

[0060] If the difference between the voltage amplitude of the first conversion signal and the first voltage threshold is larger, the voltage amplitude of the accumulated signal decreases faster, and the voltage amplitude of the accumulated signal is smaller than the second voltage amplitude sooner, which makes the first comparator U2 output a high level earlier, thereby driving the first switch tube Q1 to trigger the load module 60 to generate overload protection earlier; if the difference between the voltage amplitude of the first conversion signal and the first voltage threshold is smaller, the voltage amplitude of the accumulated signal decreases slower, and the voltage amplitude of the accumulated signal is smaller than the second voltage amplitude later, which makes the first comparator U2 output a high level later, thereby driving the first switch tube Q1 to trigger the load module 60 to generate overload protection later, thereby achieving better protection of the power devices inside the power supply and enhancing the circuit reliability.

[0061] In one embodiment, Figure 3 As shown, the signal input circuit 10 includes a transformer T1, a second switch tube Q2 and a primary winding of a current transformer L1; the primary end of the transformer T1 is used to connect to the input power supply 50, the secondary end of the transformer T1 is connected to the first end of the primary winding of the current transformer L1, the second end of the primary winding of the current transformer L1 is connected to the drain of the second switch tube Q2, the source of the second switch tube Q2 is connected to the ground wire, and the gate of the second switch tube Q2 is used to connect to the control chip 40.

[0062] The current transformer L1 has a primary winding and a secondary winding. The control chip 40 provides a PWM signal to the gate of the second switch tube Q2 to drive the second switch tube Q2 to perform high-frequency switching, thereby transmitting the input signal of the input power supply 50 through the transformer T1 and the primary winding of the current transformer L1, thereby obtaining a triangular wave switching current signal, so as to transmit the triangular wave switching current signal to the signal conversion circuit 20.

[0063] In one embodiment, Figure 3 As shown, the signal input circuit 10 includes a fourth resistor R4 and a fifth resistor R5; the first end of the fourth resistor R4 is connected to the source of the second switch tube Q2, the second end of the fourth resistor R4 is connected to the gate of the second switch tube Q2, the first end of the fifth resistor R5 is connected to the gate of the second switch tube Q2, and the second end of the fifth resistor R5 is connected to the control chip 40.

[0064] Among them, by connecting the fifth resistor R5 to the gate of the second switch tube Q2, the driving current can be limited to prevent the instantaneous driving current from being too large, resulting in insufficient driving ability or damage to the device. By connecting the fourth resistor R4 between the gate and the source of the second switch tube Q2, the gate current of the second switch tube Q2 can be limited to prevent excessive current from damaging the second switch tube Q2, and the second switch tube Q2 can be protected from excessive current shocks, overheating and damage.

[0065] In one embodiment, Figure 3 As shown, the signal conversion circuit 20 includes a rectifier module 210 and a secondary winding of a current transformer L1; the rectifier module 210 is connected between the integral trigger circuit 30 and the secondary winding of the current transformer L1, and the secondary winding of the current transformer L1 is matched with the primary winding of the current transformer L1.

[0066] The secondary winding of the current transformer L1 is used to convert the triangular wave switching current according to the matching induction of the primary winding of the current transformer L1, thereby obtaining a converted AC signal. The rectifier module 210 is used to sort out the AC transmitted by the secondary winding of the current transformer L1, thereby obtaining a DC signal (i.e., a first conversion signal).

[0067] In one example, if Figure 3As shown, the rectifier module 210 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third capacitor C3, a fourth capacitor C4, a second diode D2 and a third diode D3; the first end of the sixth resistor R6 is connected to the first end of the secondary winding of the current transformer L1, the second end of the sixth resistor R6 is connected to the second end of the secondary winding of the current transformer L1, and the second end of the secondary winding of the current transformer L1 is connected to the ground wire; the anode of the second diode D2 is connected to the first end of the sixth resistor R6, the cathode of the second diode D2 is connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is connected to the ground wire. The second end of the sixth resistor R6 is connected; the first end of the eighth resistor R8 is connected to the cathode of the second diode D2, the second end of the eighth resistor R8 is connected to the anode of the third diode D3, the first end of the third capacitor C3 is connected to the second end of the eighth resistor R8, and the second end of the third capacitor C3 is connected to the second end of the sixth resistor R6; the cathode of the third diode D3 is connected to the first end of the fourth capacitor C4, the second end of the fourth capacitor C4 is connected to the second end of the sixth resistor R6, the first end of the ninth resistor R9 is respectively connected to the first end of the fourth capacitor C4 and the integration trigger circuit 30, and the second end of the ninth resistor R9 is connected to the second end of the sixth resistor R6.

[0068] When the current of the input power supply 50 in the signal input circuit 10 (i.e., the current flowing through the second switch tube Q2) is different in magnitude, the curve of the corresponding first conversion signal after passing through the rectifier module 210 is different. For example, the larger the current flowing through the second switch tube Q2, the larger the voltage amplitude of the first conversion signal converted by the current transformer L1 and output after being sorted by the rectifier module 210; the smaller the current flowing through the second switch tube Q2, the smaller the voltage amplitude of the first conversion signal converted by the current transformer L1 and output after being sorted by the rectifier module 210. Based on the signal conversion circuit 20 connected to the integral trigger circuit 30, when the current flowing through the second switch tube Q2 is larger, the integral trigger circuit 30 triggers the protection faster, and when the current flowing through the second switch tube Q2 is smaller, the integral trigger circuit 30 triggers the protection later, thereby realizing reliable and safe overload protection for the load module 60.

[0069] In one embodiment, a switching power supply is further provided, comprising any one of the delay protection circuits described above.

[0070] For the specific description of the delay protection circuit, reference may be made to the specific description of the delay protection circuit in the above embodiment, which will not be repeated here.

[0071] Based on the signal input circuit, the control chip and the input power supply are connected; the signal conversion circuit is connected to the signal input circuit, the integral trigger circuit is connected to the signal conversion circuit, and the integral trigger circuit is connected to the load module. The signal input circuit obtains the control signal transmitted by the control chip, and controls the input power supply to transmit the input signal according to the control signal; the signal conversion circuit obtains the input signal, and converts the input signal to obtain a first conversion signal; the integral trigger circuit obtains the first conversion signal, integrates and accumulates the first conversion signal to obtain an accumulated signal, and when the accumulated signal meets the preset conditions, the load module is triggered to perform overload protection, thereby realizing reliable and safe triggering delay protection for the load module.

[0072] For example, when the load current of the load module reaches the set protection threshold, the protection cannot be triggered immediately. Instead, the delay protection time is different according to the load current exceeding the set value. The more the load current exceeds the set protection threshold, the shorter the delay protection time; the less the load current exceeds the set protection threshold, the longer the delay protection time. Thus, when the overload current is not much, the power supply will not be protected quickly, and the overload can be allowed for a period of time; but when the overload current is too much, the protection can be triggered very quickly.

[0073] In the above-mentioned embodiment, by integrating and accumulating the input electrical signal, when the input load is heavier, the trigger delay protection time is shorter, and the power devices inside the power supply are better protected; when the output load is lighter, the delay trigger time is longer, allowing a longer overload period, thereby realizing the triggering of delayed overload protection by integrating and accumulating energy, and there is no need to use large-capacity capacitors, thereby reducing the hardware cost of the switching power supply, reducing the size of the switching power supply, and enhancing the reliability of the switching circuit.

[0074] In one embodiment, a motor control device is further provided, comprising a switching power supply as described above.

[0075] For the specific description of the switching power supply, reference may be made to the specific description of the switching power supply in the above embodiment, which will not be repeated here.

[0076] For example, the motor control device can be applied to electric doors. The load module is the motor. The switching power supply provides load current to the motor, and the motor provides steering torque to the door. At the moment when the motor drives the door to start moving, a current exceeding the rated load of the power supply is required. By setting the parameters reasonably, it can be ensured that the overload current during the startup process will not cause power protection, so that the door can rotate normally; but when the door is blocked by external force during rotation, the motor will continue to increase the load current and increase the torque to try to resist this external force. At this time, the delay protection circuit needs to act quickly to prevent the large torque from causing the door to pinch people or animals.

[0077] It should be noted that the motor control device may also include devices such as a display, and the specific motor control device may include more components than those described in the above embodiments, or combine certain components, or have a different arrangement of components.

[0078] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A time-delay protection circuit, characterized in that: include: A signal input circuit, the signal input circuit is used to connect the control chip and the input power supply; the signal input circuit is configured to obtain a control signal transmitted by the control chip, and control the input power supply to transmit an input signal according to the control signal; A signal conversion circuit, the signal conversion circuit is connected to the signal input circuit, and the signal conversion circuit is configured to obtain the input signal and perform conversion processing on the input signal to obtain a first conversion signal; An integral trigger circuit, wherein the integral trigger circuit is connected to the signal conversion circuit, and the integral trigger circuit is used to connect a load module. The integral trigger circuit is configured to obtain the first conversion signal, perform integral accumulation processing on the first conversion signal to obtain an accumulated signal, and when the accumulated signal meets a preset condition, trigger the load module to perform overload protection.

2. The time delay protection circuit according to claim 1, characterized in that: The integral trigger circuit is also configured to perform an integral comparison operation on the voltage amplitude of the first conversion signal and the first voltage threshold to obtain the accumulated signal when the voltage amplitude of the first conversion signal is greater than the first voltage threshold; and to trigger the load module to perform overload protection when the voltage amplitude of the accumulated signal is less than the second voltage threshold.

3. The time delay protection circuit according to claim 1, characterized in that: The integral trigger circuit comprises an integral accumulation circuit and a trigger circuit; The integral accumulation circuit is connected between the trigger circuit and the signal conversion circuit, and the trigger circuit is connected to the load module.

4. The time delay protection circuit according to claim 3, characterized in that: The integral accumulation circuit includes a first resistor, a second resistor, a first capacitor, a second capacitor, a first diode and a first operational amplifier; The first end of the first resistor is connected to the signal conversion circuit, the second end of the first resistor is connected to the negative input end of the first operational amplifier, and the positive input end of the first operational amplifier is used to access a voltage signal corresponding to a first voltage threshold; The first end of the first capacitor is connected to the second end of the first resistor, and the second end of the first capacitor is connected to the output end of the first operational amplifier; the cathode of the first diode is connected to the output end of the first operational amplifier, the anode of the first diode is connected to the first end of the second resistor, the first end of the second resistor is connected to the trigger circuit, the second end of the second resistor is connected to the power supply, the first end of the second capacitor is connected to the power supply, and the second end of the second capacitor is connected to the ground wire; the power supply end of the first operational amplifier is connected to the power supply, and the ground end of the first operational amplifier is connected to the ground wire.

5. The time-delay protection circuit according to claim 3, characterized in that: The trigger circuit includes a third resistor, a first switch tube and a first comparator; The negative input terminal of the first comparator is connected to the integral accumulation circuit, the positive input terminal of the first comparator is used to access the voltage signal corresponding to the second voltage threshold, and the output terminal of the first comparator is connected to the first end of the third resistor; the second end of the third resistor is connected to the gate of the first switching tube, the source of the first switching tube is connected to the ground wire, and the drain of the first switching tube is connected to the negative electrode module.

6. The time-delay protection circuit according to claim 1, characterized in that: The signal input circuit includes a transformer, a second switch tube and a primary winding of a current transformer; The primary end of the transformer is used to connect to the input power supply, the secondary end of the transformer is connected to the first end of the primary winding of the current transformer, the second end of the primary winding of the current transformer is connected to the drain of the second switch tube, the source of the second switch tube is connected to the ground wire, and the gate of the second switch tube is used to connect to the control chip.

7. The time delay protection circuit according to claim 6, characterized in that: The signal input circuit includes a fourth resistor and a fifth resistor; The first end of the fourth resistor is connected to the source of the second switch tube, the second end of the fourth resistor is connected to the gate of the second switch tube, the first end of the fifth resistor is connected to the gate of the second switch tube, and the second end of the fifth resistor is connected to the control chip.

8. The time-delay protection circuit according to claim 6, characterized in that: The signal conversion circuit includes a rectifier module and a secondary winding of the current transformer; The rectifier module is connected between the integral trigger circuit and the secondary winding of the current transformer, and the secondary winding of the current transformer is matched with the primary winding of the current transformer.

9. The time-delay protection circuit according to claim 8, characterized in that: The rectifier module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a fourth capacitor, a second diode and a third diode; The first end of the sixth resistor is connected to the first end of the secondary winding of the current transformer, the second end of the sixth resistor is connected to the second end of the secondary winding of the current transformer, and the second end of the secondary winding of the current transformer is connected to the ground wire; the anode of the second diode is connected to the first end of the sixth resistor, the cathode of the second diode is connected to the first end of the seventh resistor, and the second end of the seventh resistor is connected to the second end of the sixth resistor; The first end of the eighth resistor is connected to the cathode of the second diode, the second end of the eighth resistor is connected to the anode of the third diode, the first end of the third capacitor is connected to the second end of the eighth resistor, and the second end of the third capacitor is connected to the second end of the sixth resistor; the cathode of the third diode is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the second end of the sixth resistor, the first end of the ninth resistor is respectively connected to the first end of the fourth capacitor and the integration trigger circuit, and the second end of the ninth resistor is connected to the second end of the sixth resistor.

10. A switching power supply, characterized in that: Comprising the time delay protection circuit as described in any one of claims 1 to 9.

11. A motor control device, characterized in that: Comprising a switching power supply as claimed in any one of claim 10.

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