Surge current prevention circuit and electronic equipment
By coordinating the control module and switching devices of the surge protection circuit, the surge current at startup is detected and diverted, solving the problem of damage to the switching devices during startup and ensuring device safety and continuous power supply to the load.
Patent Information
- Application Number
- CN202520271130.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-19
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2035-02-19
AI Technical Summary
In the existing technology, the surge current during power-on can easily break down the switching device, causing permanent failure. The existing technology is difficult to effectively avoid this damage.
A surge protection circuit is adopted, including a control module, first and second switching devices. By detecting the power supply current and controlling the second switching device to conduct and shunt the current when it exceeds the threshold, the current flowing through the first switching device is reduced. Combined with a current-limiting resistor and a switching power supply module, the power supply to the load is ensured to be uninterrupted.
It effectively avoids damage to the switching devices from the inrush current during startup, ensuring device safety, and provides continuous power supply to the load when the devices are turned off, thus improving the reliability of the equipment.
Smart Images
Figure CN223758177U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of preventing inrush current, especially relates to a circuit and electronic equipment of preventing inrush current. BACKGROUND
[0002] Inrush current refers to the peak current flowing into the device at the moment of connecting the power supply of the electrical equipment. It is usually much higher than the steady-state current during normal operation of the device. The heat generated by excessive inrush current is likely to exceed the bearing range of semiconductor devices (such as diodes, triodes, and integrated circuit chips), causing the internal semiconductor structure of the chip to be broken down and the device to be permanently disabled.
[0003] The inrush current generated when the device starts may break the switching device, causing difficulties in selecting the switching device. The prior art determines the selection of the subsequent switching device by measuring the inrush current when starting, but the switching device used for the first time may be damaged by the inrush current. SUMMARY
[0004] The main purpose of the utility model is to provide a circuit and electronic equipment for preventing inrush current, aiming to avoid damage to the switching device caused by inrush current when starting.
[0005] To achieve the above-mentioned purpose, the circuit for preventing inrush current provided by the utility model comprises a control module, a first switching device, and a second switching device.
[0006] The first end of the first switching device is connected to an external power supply, the second end is connected to a load and a current detection end of the control module, and the controlled end is connected to the first end of the control module. The first end of the second switching device is connected to the first end of the first switching device, the second end is grounded, and the controlled end is connected to the second end of the control module.
[0007] The control module is used for detecting the power supply current output by the external power supply, and controlling the second switching device to turn on the path between the external power supply and the ground when the power supply current is greater than or equal to the current threshold.
[0008] Optionally, the circuit for preventing inrush current further comprises a switching power supply module.
[0009] The first end of the switching power supply module is connected to the first end of the first switching device, the second end is connected to the load, and the controlled end is connected to the control module.
[0010] The control module is further used for outputting a power supply signal to the switching power supply module when the power supply current is greater than or equal to the current threshold.
[0011] The switching power supply module is configured to turn on a path between the load and the first end of the first switching device when the power supply signal is received.
[0012] Optionally, the switching power supply module comprises a third switching device and a first resistor.
[0013] The third switching device and the first resistor are connected in series between the first end of the first switching device and the load, and a controlled end of the third switching device is connected to the control module.
[0014] The control module is further configured to control the third switching device to turn on the path between the load and the first end of the first switching device and control the first switching device to enter an off state when the power supply current is greater than or equal to a current threshold.
[0015] Optionally, the circuit for preventing inrush current further comprises a second resistor.
[0016] The second resistor is connected in series with the second switching device between the first end of the first switching device and the ground.
[0017] Optionally, the circuit for preventing inrush current comprises a fourth switching device.
[0018] The fourth switching device has a first end connected to the first voltage, a second end connected to a controlled end of the second switching device, and a controlled end connected to a second end of the control module.
[0019] Optionally, the second end of the control module is further connected to a controlled end of the third switching device.
[0020] Optionally, the circuit for preventing inrush current further comprises a third resistor.
[0021] The third resistor has a first end connected to the first voltage and a second end connected to a first end of the fourth switching device.
[0022] Optionally, the control module comprises a current detection circuit and a master control circuit.
[0023] The current detection circuit has a first end connected to the second end of the first switching device and the load, and a second end connected to a first end of the master control circuit; the master control circuit has a second end connected to a controlled end of the first switching device, and a third end connected to a controlled end of the second switching device.
[0024] The current detection circuit is configured to detect a current value flowing through the first switching device and output the current value to the master control circuit.
[0025] The master control circuit is configured to control the second switch device to turn on a path between the external power supply and the ground when the current value is greater than or equal to a current threshold.
[0026] The utility model discloses still propose a kind of electronic equipment, the electronic equipment includes: power supply circuit and the circuit of the anti-inrush current;The power supply circuit connects the first end of the first switch device and the first end of the second switch device;
[0027] The power supply circuit is configured to output a power supply voltage.
[0028] The utility model discloses a kind of anti-inrush current circuit and electronic equipment, anti-inrush current circuit includes: control module, first switch device and second switch device;The first end of the first switch device is connected with external power supply, second end connects load and the current detection end of the control module, controlled end connects the first end of the control module;The first end of the second switch device is connected with the first end of the first switch device, second end is grounded, and controlled end connects the second end of the control module;The control module is configured to detect the power supply current output by the external power supply, and when the power supply current is greater than or equal to a current threshold, the second switch device is controlled to turn on a path between the external power supply and the ground.The utility model controls the second switch device to shunt when the current value flowing through the first switch device is not less than current threshold, reduces the current value flowing through the first switch device, to avoid the damage of start-up inrush current to switch device. BRIEF DESCRIPTION OF DRAWINGS
[0029] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the following will briefly introduce the drawings needed to be used in embodiment or prior art description, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to the structure shown in these drawings without creating labor.
[0030] Figure 1 It is the structural schematic diagram of the anti-inrush current circuit of the utility model embodiment;
[0031] Figure 2 It is the first structural schematic diagram of the anti-inrush current circuit first embodiment of the utility model;
[0032] Figure 3 It is the second structural schematic diagram of the anti-inrush current circuit first embodiment of the utility model;
[0033] Figure 4 It is the third structural schematic diagram of the anti-inrush current circuit first embodiment of the utility model;
[0034] Figure 5 Figure 1 is a first structural schematic diagram of a first embodiment of a circuit for preventing inrush current of the utility model;
[0035] Figure 6 Figure 2 is a second structural schematic diagram of the first embodiment of the circuit for preventing inrush current of the utility model;
[0036] Figure 7 Figure 2 is a second structural schematic diagram of the first embodiment of the circuit for preventing inrush current of the utility model.
[0037] Explanation of reference numerals:
[0038]
[0039] The utility model realizes the purpose, functional characteristics and advantages, which will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION
[0040] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.
[0041] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the utility model are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.
[0042] In the utility model, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood broadly, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through intermediate medium; can be internal communication of two elements or mutual action relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0043] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.
[0044] Referring to Figure 1 The utility model provides a kind of circuit 10 of preventing inrush current, comprising: control module 110, first switching device 120 and second switching device 130;
[0045] The first end of the first switching device 120 is connected to an external power supply, the second end is connected to a load and the current detection end of the control module 110, and the controlled end is connected to the first end of the control module 110;The first end of the second switching device 130 is connected to the first end of the first switching device 120, the second end is grounded, and the controlled end is connected to the second end of the control module 110;
[0046] The control module 110 is used for detecting the power supply current output by the external power supply, and when the power supply current is greater than or equal to the current threshold, the second switching device 130 is controlled to turn on the path between the external power supply and the ground.
[0047] It should be noted that the first switching device 120 is arranged in the loop of the external power supply and the load. When the device is powered on, the external power supply outputs a power supply voltage. Since inrush current will be generated when powered on, the inrush current flows through the first switching device 120 to the load. Excessive inrush current may generate heat at the first switching device 120 and the load, damaging the first switching device 120 and the load. It is easy to understand that, according to the heat effect of current, Q is the heat generated by current, I is the current value, R is the equivalent resistance of the switching device, and t is the current duration.
[0048] The excessive inrush current forms heat which can damage the first switch device 120 and the load, but it is noted that the heat is also related to the current duration, in the initial state, the second switch device 130 is off, and the power supply current output by the external power supply reaches the load through the first switch device 120 which is turned on. The utility model uses the control module 110 to detect the power supply current output by the external power supply, that is, the current value flowing through the first switch device 120, and compares it with the current threshold value; when the power supply current value is greater than or equal to the current threshold value, the second switch device 130 is controlled to shunt the inrush current, thereby reducing the current value flowing through the first switch device 120, and in particular, the control module 110 can also control the first switch device 120 to turn off the path between the external power supply and the load when the power supply current value is greater than or equal to the current threshold value. It should be noted that the utility model uses the current threshold value to determine whether the inrush current occurs, and the current threshold value is determined by the specific value of the R&D personnel.
[0049] It should be noted that the inrush current lasts for a short time, and after the inrush current, the external power supply needs to restore the power supply for the load; in addition, the second switch device 130 turns on the path between the external power supply and the ground, and in the utility model, it is not limited whether there are other devices, such as resistors, in the path between the external power supply and the ground. If there are no other devices, it may cause the current flowing through the second switch device 130 to be too large, which may cause hidden dangers, and the current flowing through the first switch device 120 to the load is too small to support the load to work. To solve the above problems, the anti-inrush current circuit 10 further comprises a second resistor R2.
[0050] The second resistor R2 and the second switch device 130 are connected in series between the external power supply and the ground. The second resistor R2 is a current limiting resistor, which can reduce the current flowing through the second switch device 130 to the ground and avoid the problem that the current flowing into the load is too small.
[0051] The first switch device 120 can be a MOS tube, an IGBT tube, a triode or a BJT tube, etc., and the second switch device 130 can be a MOS tube, an IGBT tube, a triode or a BJT tube, etc. It is easy to understand that the turn-on speed of the second switch device 130 affects the duration of the inrush current flowing through the first switch device 120; the second switch device 130 needs to use a device with fast switching speed.
[0052] The utility model discloses a kind of circuit 10 and electronic equipment of anti-inrush current, the circuit 10 of anti-inrush current includes: control module 110, first switching device 120 and second switching device 130;The first end of the first switching device 120 is connected to external power supply, the second end is connected load and the current detection end of the control module 110, controlled end is connected the first end of the control module 110;The first end of the second switching device 130 is connected the first end of the first switching device 120, the second end is grounded, controlled end is connected the second end of the control module 110;The control module 110 is used to detect the power supply current that the external power supply outputs, and when the power supply current is greater than or equal to current threshold value, the second switching device 130 is controlled to turn on the passageway between the external power supply and ground.The utility model controls second switching device 130 to shunt when the current value flowing through the first switching device 120 is not less than current threshold value, reduce the current value flowing through the first switching device 120, avoid the damage of switch device to start-up inrush current.
[0053] After detecting that the power supply current of the external power supply is greater than or equal to the current threshold value, the third switching device 1410 is controlled to turn on the time required, and the current flowing through the first switching device 120 gradually reduces also the time required;Suppose that, after detecting that the power supply current is greater than current threshold value, the third switching device 1410 is turned on for the first duration, and within the first duration, the current value flowing through the first switching device 120 still generates heat under the action of current thermal effect, and the heat generated in the first duration may be superimposed with the heat of the first switching device 120 itself, resulting in damage to the first switching device 120.In order to solve the problem, the utility model controls the first switching device 120 to be turned off by the control module 110 when the power supply current is not less than current threshold value, which is conducive to the timely cooling of the first switching device 120.In order to supply power of the load is not interrupted when the first switching device 120 is turned off, the utility model first embodiment is proposed, refer to Figure 2 , the anti-inrush current circuit 10 further includes: switching power supply module 140;
[0054] The first end of the switching power supply module 140 is connected to the external power supply, the second end is connected to the load, and the controlled end is connected to the control module 110;
[0055] The control module 110 is also used to output a power supply signal to the switching power supply module 140 when the power supply current is greater than or equal to current threshold value;
[0056] The switching power supply module 140 is used to turn on the passageway between the load and the external power supply when receiving the power supply signal.
[0057] It should be noted that the switching power supply module 140 is arranged between the external power supply and the load, and after receiving the power supply signal, the switching power supply module 140 turns on the path between the load and the external power supply, that is, provides the load with the voltage and output current of the external power supply to supply power to the load. When the power supply current is greater than or equal to the current threshold, the control module 110 outputs a power supply signal to the switching power supply module 140. It is easy to understand that the switching power supply module 140 can realize the function of supplying power to the load when the first switching device 120 is turned off.
[0058] With reference to Figure 3 , the switching power supply module 140 comprises a third switching device 1410 and a first resistor R1.
[0059] The third switching device 1410 and the first resistor R1 are arranged in series between the external power supply and the load; and the controlled end of the third switching device 1410 is connected to the control module 110.
[0060] The control module 110 is further configured to control the third switching device 1410 to turn on the path between the load and the external power supply, and control the first switching device 120 to enter the off state when the power supply current is greater than or equal to the current threshold.
[0061] It is easy to understand that the third switching device 1410 and the first resistor R1 are arranged in series between the external power supply and the load, and the present embodiment does not limit the connection of the third switching device 1410 or the first resistor R1 to the external power supply. The third switching device 1410 is used to turn on / off the path between the external power supply and the load. The first resistor R1 is a current limiting resistor, which avoids that the current input to the load is too large.
[0062] The third switching device 1410 can be a MOS tube, an IGBT tube, a triode, or a BJT tube, etc.
[0063] Considering that the second switching device 130 is arranged between the external power supply and the ground, in order to timely guide the inrush current into the ground, the on degree of the second switching device 130 needs to be as large as possible. It is easy to understand that the control module 110 uses a controller such as MCU, SOC, FPGA, or DSP, and the output driving capability of the controller is limited, which may not complete the on degree required by the second switching device 130, that is, the current value passing through the second switching device 130. To solve the above problem, the second embodiment of the utility model is proposed, with reference to Figure 5 、 Figure 6 and Figure 7 The anti-inrush current circuit 10 comprises a fourth switching device 150.
[0064] The first end of the fourth switch device 150 is connected to the first voltage, the second end is connected to the controlled end of the second switch device 130, and the controlled end is connected to the second end of the control module 110.
[0065] It should be noted that when the fourth switch device 150 is turned on, the voltage at the controlled end of the second switch device 130 is the first voltage. The control module 110 can control the fourth switch device 150 to be turned on when the power current is greater than or equal to the current threshold, so that the voltage at the controlled end of the second switch device 130 is the first voltage; the first voltage is determined by the researchers, so that the second switch device 130 completes the required conduction degree under the action of the first voltage. The required conduction degree of the second switch device 130 is determined by the researchers according to the specific circuit requirements. In particular, the second switch device 130 is completely turned on under the action of the first voltage. The fourth switch device 150 can be a MOS tube, an IGBT tube, a triode or a BJT tube, etc.
[0066] The second end of the control module 110 is also connected to the controlled end of the third switch device 1410. In combination with the above, it is easy to understand that the control module 110 controls the third switch device 1410 to be turned on, controls the second switch device 130 to be turned on, and controls the fourth switch device 150 to be turned on when the power current is greater than or equal to the current threshold; wherein the fourth switch device 150 being turned on is a prerequisite for the second switch device 130 being turned on; therefore, the second end of the control module 110 can be connected to the controlled end of the third switch device 1410 and the controlled end of the fourth switch device 150 at the same time, using the same end of the control module 110 to realize the turn-on of the two switch devices, without considering the software timing, which can reduce the control program and the influence of electromagnetic interference on the turn-on and turn-off of the switch device.
[0067] The anti-inrush current circuit 10 further comprises a third resistor R3.
[0068] The first end of the third resistor R3 is connected to the first voltage, and the second end is connected to the first end of the fourth switch device 150. The third resistor R3 is a current limiting resistor, which is used to avoid excessive current flowing through the fourth switch device 150.
[0069] The first switch device, the second switch device, the third switch device and the fourth switch device can be MOS tubes, which are respectively a first MOS tube Q1, a second MOS tube Q2, a third MOS tube Q3 and a fourth MOS tube Q4.
[0070] The control module 110 comprises a current detection circuit and a main control circuit.
[0071] The first end of the current detection circuit is connected with the external power supply, and the second end is connected with the first end of the main control circuit; the second end of the main control circuit is connected with the controlled end of the first switch device 120, and the third end is connected with the controlled end of the second switch device 130;
[0072] The current detection circuit is used for detecting the power supply current output by the external power supply and outputting the power supply current value to the main control circuit.
[0073] The main control circuit is used for controlling the second switch device 130 to turn on the path between the external power supply and the ground when the power supply current value is greater than or equal to the current threshold.
[0074] The main control module can include an MCU, an SOC, an FPGA or a DSP controller. In particular, the main control module is a current detector.
[0075] The utility model also proposes an electronic equipment, electronic equipment includes: power supply circuit and the circuit 10 of preventing inrush current, the power supply circuit connects the first end of first switch device 120 and the first end of second switch device 130,
[0076] The power supply circuit is used for outputting a power supply voltage.
[0077] The specific structure of the circuit 10 of preventing inrush current is referred to the above-mentioned embodiments. Since the electronic equipment adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here. The above-mentioned is only the optional embodiments of the utility model, and does not limit the patent range of the utility model, and all the equivalent structural transformations made by using the utility model specification and the attached drawings, or directly / indirectly applied in other related technical fields under the inventive concept of the utility model are included in the patent protection range of the utility model.
Claims
1. A circuit for preventing inrush current, characterized by, The anti-inrush current circuit comprises a control module, a first switch device and a second switch device; a first end of the first switch device is connected to an external power supply, a second end of the first switch device is connected to a load and a current detection end of the control module, and a controlled end of the first switch device is connected to a first end of the control module; a first end of the second switch device is connected to the first end of the first switch device, a second end of the second switch device is connected to ground, and a controlled end of the second switch device is connected to a second end of the control module; the control module is configured to detect a power supply current output by the external power supply, and control the second switch device to turn on a path between the external power supply and the ground when the power supply current is greater than or equal to a current threshold.
2. The inrush current protection circuit of claim 1, wherein, The anti-inrush current circuit further comprises a switching power supply module; a first end of the switching power supply module is connected to the external power supply, a second end of the switching power supply module is connected to the load, and a controlled end of the switching power supply module is connected to the control module; the control module is further configured to output a power supply signal to the switching power supply module when the power supply current is greater than or equal to the current threshold; the switching power supply module is configured to turn on a path between the load and the external power supply when the power supply signal is received.
3. The inrush current protection circuit of claim 2, wherein, The switching power supply module comprises a third switch device and a first resistor; the third switch device and the first resistor are connected in series between the external power supply and the load; and a controlled end of the third switch device is connected to the control module; the control module is further configured to control the third switch device to turn on the path between the load and the external power supply, and control the first switch device to enter an off state when the power supply current is greater than or equal to the current threshold.
4. The inrush current protection circuit of claim 2, wherein, The anti-inrush current circuit further comprises a second resistor; the second resistor is connected in series with the second switch device between the external power supply and the ground.
5. The inrush current protection circuit of claim 4, wherein, The anti-inrush current circuit comprises a fourth switch device; a first end of the fourth switch device is connected to a first voltage, a second end of the fourth switch device is connected to a controlled end of the second switch device, and a controlled end of the fourth switch device is connected to a second end of the control module.
6. The inrush current protection circuit of claim 5, wherein, The second end of the control module is further connected to a controlled end of the third switch device.
7. The inrush current protection circuit of claim 6, wherein, The anti-inrush current circuit further comprises a third resistor; a first end of the third resistor is connected to the first voltage, and a second end of the third resistor is connected to a first end of the fourth switch device.
8. The inrush current preventing circuit according to any one of claims 1 to 7, wherein The control module comprises a current detection circuit and a main control circuit; a first end of the current detection circuit is connected to the external power supply, and a second end of the current detection circuit is connected to a first end of the main control circuit; a second end of the main control circuit is connected to a controlled end of the first switch device, and a third end of the main control circuit is connected to a controlled end of the second switch device; the current detection circuit is configured to detect a power supply current output by the external power supply, and output a power supply current value to the main control circuit; the main control circuit is configured to control the second switch device to turn on a path between the external power supply and the ground when the power supply current value is greater than or equal to a current threshold.
9. An electronic device, comprising: The electronic device comprises a power supply circuit and an anti-inrush current circuit according to any one of claims 1 to 8; the power supply circuit is connected to a first end of the first switch device and a first end of the second switch device. The power supply circuit is configured to output a power supply voltage.