Protection circuit and electronic equipment

Abstract

The utility model discloses a protection circuit and an electronic device, the protection circuit comprises a power supply end, an output end and a positive electrode used for being electrically connected with an electric load, an on-off control unit comprises a first acquisition end and a first on-off control end, and the first acquisition end is electrically connected with the power supply end; the switch unit comprises a second on-off control end, a first connecting end and a second connecting end, the second on-off control end is electrically connected with the first on-off control end and the power supply end, the first connecting end of the switch unit is electrically connected with the negative electrode of the electricity load, and the second connecting end is grounded; wherein the on-off control end unit is configured to control the switch unit to work according to the voltage acquired by the first acquisition end so as to realize overcurrent, overvoltage and reverse connection protection.

Description

TECHNICAL FIELD

[0001] The utility model relates to integrated circuit technical field, especially relate to a protection circuit and electronic equipment. BACKGROUND

[0002] With the rapid development of intelligent hardware and Internet of Things technology, electronic devices with screens (such as smart photo frames, portable displays, smart companion devices, etc.) are increasingly appearing in daily life. These devices not only have interactive functions, but also usually have built-in batteries to achieve portability, and can be powered by external power adapters or chargers. However, users often use adapters of different brands or specifications for charging, which leads to compatibility and safety challenges when the device is connected to the power supply.

[0003] In the prior art, the power interface of electronic devices with screens usually uses basic circuit protection schemes, such as simple diode reverse connection prevention, to achieve preliminary protection of the circuit.

[0004] Current technical means generally lack effective integration of power port reverse connection protection and overcurrent protection. It cannot effectively deal with the problems of high voltage, reverse connection and overcurrent that may be caused by the use of non-official adapters by users, which significantly increases the risk of damage to the device hardware. UTILITY MODEL CONTENT

[0005] The main purpose of the utility model is to provide a protection circuit to solve the problem of high voltage, reverse connection and overcurrent damage to the device.

[0006] To achieve the above purpose, the utility model provides a protection circuit applied to an electronic device, which comprises:

[0007] A power supply end;

[0008] An output end for electrically connecting the positive pole of the power load;

[0009] A on-off control unit, which comprises a first collection end and a first on-off control end, and the first collection end is electrically connected to the power supply end;

[0010] A switch unit, which comprises a second on-off control end, a first connection end and a second connection end, the second on-off control end is electrically connected to the first on-off control end and the power supply end, the first connection end of the switch unit is used for electrically connecting the negative pole of the power load, and the second connection end is grounded;

[0011] The on-off control end unit is configured to control the operation of the switch unit according to the voltage collected by the first collection end.

[0012] In some embodiments, the on-off control unit comprises a voltage stabilizing device, a cathode of the voltage stabilizing device being electrically connected to the first collection terminal;

[0013] A first switch tube, a trigger end of the first switch tube being electrically connected to an anode of the voltage stabilizing device, one conduction end of the first switch tube being electrically connected to the first on-off control terminal, and the other conduction end being grounded.

[0014] In some embodiments, the on-off control unit further comprises a voltage dividing module, the anode of the voltage stabilizing device being electrically connected to the trigger end of the first switch tube through the voltage dividing module.

[0015] In some embodiments, the switch unit comprises a second switch tube, a gate of the second switch tube being electrically connected to the second on-off control terminal, a first conduction end of the second switch tube being electrically connected to the first connection terminal, and a second conduction end of the second switch tube being grounded.

[0016] In some embodiments, the switch unit further comprises a third switch tube, a gate of the third switch tube being electrically connected to the second on-off control terminal, and the second conduction end of the second switch tube being grounded through the third switch tube.

[0017] In some embodiments, the protection circuit further comprises a transient voltage protection module, the transient voltage protection module comprising a transient voltage suppression device, one end of the transient voltage suppression device being electrically connected to the power supply terminal, and a release end of the transient voltage suppression device being grounded.

[0018] In some embodiments, the transient voltage protection module further comprises an electrostatic tube, one end of the electrostatic tube being electrically connected to the power supply terminal, and the other end being grounded.

[0019] In some embodiments, a filter circuit is further included, the filter circuit comprising a third connection terminal and a fourth connection terminal, the third connection terminal being electrically connected to the transient voltage protection module and the power supply terminal, and the fourth connection terminal being electrically connected to the output terminal, the filter circuit being used for filtering the power supply input through the power supply terminal.

[0020] In some embodiments, the filter circuit comprises:

[0021] An inductor, one end of the inductor being electrically connected to the third connection terminal, and the other end of the inductor being electrically connected to the fourth connection terminal;

[0022] A capacitor, one end of the capacitor being electrically connected to the other end of the inductor, and the other end of the capacitor being grounded.

[0023] The utility model further proposes an electronic equipment comprising the protection circuit of preceding embodiments.

[0024] The utility model discloses the beneficial effect of technical scheme is in: through the on-off control unit real -time detection power end's voltage and current, and according to the detection result control switch unit's working condition, realize the intelligent management of circuit. When power end voltage or current exceeds the preset threshold value, and the on-off control unit controls switch unit to cut off the connection of electric load and ground, avoids the damage of load due to overcurrent or overvoltage. When the positive and negative of power supply are connected reversely, the control end of switch unit cannot obtain drive voltage, thereby shutting down the loop, prevents the circuit damage due to reverse connection, to realize overcurrent, overvoltage and reverse connection protection. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is module electric connection schematic diagram of protection circuit in the utility model one embodiment;

[0026] Figure 2 It is circuit diagram of protection circuit in the utility model one embodiment.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 10, power end;

[0029] 20, output end;

[0030] 30, electric load;

[0031] 100, on-off control unit;B1, first acquisition end;B2, first on-off control end;

[0032] D1, voltage stabilizing device;

[0033] Q1, first switch tube;

[0034] 200, voltage division module;

[0035] 300, switch unit;B3, second on-off control end;A1, first connection end;A2, second connection end;

[0036] Q2, second switch tube;A3, first conduction end;A4, second conduction end;

[0037] Q3, third switch tube;

[0038] 400, transient voltage protection module;

[0039] VR1, transient voltage suppression device;

[0040] VR2, static tube;

[0041] 500, filter circuit;A5, third connection end;A6, fourth connection end;

[0042] L1, inductance;

[0043] CE1, capacitor.

[0044] The purposes, functional features and advantages of the utility model will be further explained in combination with embodiments and with reference to the drawings. DETAILED DESCRIPTION

[0045] The schemes in the embodiments of the utility model will be clearly and completely described in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only some of the embodiments in 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 protection scope of the utility model.

[0046] 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 posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0047] It should also be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or can have a middle element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or can have a middle element.

[0048] In addition, the description of "first", "second" and the like in the utility model is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include 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 those skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0049] With reference to Figure 1 The utility model embodiment proposes a kind of protection circuit, application electronic equipment, and the protection circuit:

[0050] Power supply end 10;

[0051] Output end 20, for the positive pole of electric connection load 30;

[0052] On-off control unit 100, on-off control unit 100 includes first acquisition end B1 and first on-off control end B2, first acquisition end B1 is electrically connected power supply end 10;

[0053] The switch unit 300 includes a second on-off control end B3, a first connection end A1 and a second connection end A2, the second on-off control end B3 is electrically connected with the first on-off control end B2 and the power supply end 10, the first connection end A1 of the switch unit 300 is used for electrically connecting the negative electrode of the electrical load 30, and the second connection end A2 is grounded;

[0054] The on-off control end unit is configured to control the switch unit 300 to work according to the voltage collected by the first collection end B1.

[0055] In the embodiment, the electronic device can be a smart electronic device with a screen, such as a display screen, a smart photo frame, an advertising screen or a social companion device, etc. Specifically, it includes a device similar to a "girlfriend machine", which usually has a touch screen, an interactive function, and is designed for real-time photo sharing, video chat and other social scenarios.

[0056] The power supply end 10 is used for connecting an external power supply, and its function is to provide working voltage and current for the circuit. The power supply end 10 can be designed as a terminal or a post for facilitating reliable connection with the positive electrode of the external power supply.

[0057] The output end 20 is used for electrically connecting the positive electrode of the electrical load 30, and its function is to transmit the voltage and current of the power supply end 10 to the electrical load 30, so as to ensure the normal operation of the electronic device. The output end 20 can be designed in the form of an interface suitable for different devices.

[0058] The on-off control unit 100 is the core part of the circuit, and its function is to collect the voltage and current of the power supply end 10 in real time through the first collection end B1, and compare them with the preset threshold value. When the voltage or current reaches a certain threshold value, the on-off control unit 100 sends a control signal to the switch unit 300 to control its conduction or shutdown. The on-off control unit 100 can be realized by an integrated module, such as a special protection chip; or it can be realized by a circuit built by discrete devices, such as a combination of a voltage stabilizing tube, a resistor and a transistor.

[0059] The switch unit 300 includes a second on-off control end B3, a first connection end A1 and a second connection end A2, in the embodiment, the switch unit 300 is electrically connected between the negative electrode of the electrical load 30 and the ground, and its function is to decide whether to cut off the loop of the electrical load 30 and the ground under the control of the on-off control unit 100 according to the voltage and current state of the power supply end 10. For example, when the voltage or current of the power supply end 10 exceeds the preset threshold value, the switch unit 300 cuts off the connection between the load and the ground, so as to protect the load from damage caused by overcurrent or overvoltage.

[0060] In the embodiment, the on-off control unit 100 collects the voltage of the power supply end 10 in real time through the first collection end B1, and controls the conduction or turn-off of the switch unit 300 according to the comparison result of the collected voltage and the preset threshold value (for example, the threshold voltage is set to 10V, 24V, etc.).

[0061] Specifically, when the voltage of the power supply end 10 is lower than the preset overvoltage threshold value and does not reach the overcurrent threshold value, the on-off control unit 100 does not act. At this time, since the second on-off control end B3 of the switch unit 300 is electrically connected to the power supply end 10, the second on-off control end B3 obtains the driving voltage, and the switch unit 300 is in the conduction state. The positive electrode of the power consumption load 30 is connected to the power supply end 10 through the output end 20, and the negative electrode of the power consumption load 30 is connected to the ground through the switch unit 300, a loop is formed, and the load normally works. During the whole process, the current of the power supply end 10 flows through the output end 20, and the power consumption load 30 normally operates without interference of the additional protection circuit.

[0062] When the voltage of the power supply end 10 is higher than the preset voltage threshold value or the current exceeds the preset current threshold value, the on-off control unit 100 starts to work. Specifically, after the on-off control unit 100 detects the abnormality, the voltage of the second on-off control end B3 is lowered, so that the second on-off control end B3 of the switch unit 300 loses the driving voltage, and the switch unit 300 is turned off. After the switch unit 300 is turned off, the connection between the negative electrode of the power consumption load 30 and the ground is cut off, the loop is interrupted, the load stops working, the overvoltage or overcurrent protection is realized, and it is ensured that the power consumption load 30 will not be damaged due to excessive voltage or current when the power supply is abnormal.

[0063] If the positive electrode of the power supply is incorrectly connected to the second connection end A2 (i.e. the ground end) and the negative electrode is connected to the power supply end 10, at this time, the reverse connection state is formed. Since the second on-off control end B3 of the switch unit 300 has no driving voltage, the switch unit 300 cannot be turned on, the connection between the negative electrode of the power consumption load 30 and the ground cannot form a loop, and the load does not work, thereby avoiding damage caused by reverse connection of the power supply. This anti-reverse connection design relies on the directionality of the switch unit 300 and the real-time monitoring of the on-off control unit 100, effectively preventing the damage of reverse current to the circuit.

[0064] The beneficial effect of the technical scheme of the utility model lies in: through the on-off control unit 100, the voltage and current of the power supply end 10 are detected in real time, and the working state of the switch unit 300 is controlled according to the detection result, realizing intelligent management of the circuit.When the voltage or current of the power supply end 10 exceeds the preset threshold value, the on-off control unit 100 controls the switch unit 300 to cut off the connection between the power load 30 and the ground, avoiding damage to the load caused by overcurrent or overvoltage.When the positive and negative poles of the power supply are connected reversely, the control end of the switch unit 300 cannot obtain the driving voltage, so that the circuit is turned off, preventing the circuit from being damaged due to reverse connection.In this way, overcurrent, overvoltage and reverse connection protection are realized, and the reliability and safety of the equipment are significantly improved.

[0065] Reference Figure 2 In the embodiment, the on-off control unit 100 comprises a voltage stabilizing device D1, the cathode of the voltage stabilizing device D1 is electrically connected to the first collection end B1;

[0066] The first switch tube Q1 is electrically connected to the anode of the voltage stabilizing device D1 at the triggering end, one conduction end of the first switch tube Q1 is electrically connected to the first on-off control end B2, and the other conduction end is grounded.

[0067] In the embodiment, the voltage stabilizing device D1 can be a Zener diode, the cathode of the Zener diode is electrically connected to the first collection end B1, and the anode is grounded, which is used for monitoring whether the voltage of the power supply end 10 exceeds the preset threshold value.The first switch tube Q1 can be a triode or a MOS tube, which is used for controlling the conduction and turn-off of the switch unit 300.

[0068] When the voltage of the power supply end 10 is lower than the threshold voltage of the Zener diode, the Zener diode is in the cut-off state and does not conduct.At this time, the triggering end of the first switch tube Q1 does not have enough trigger voltage, and the first switch tube Q1 is also in the turn-off state.Due to the turn-off of the first switch tube Q1, the first on-off control end B2 of the switch unit 300 maintains a normal voltage level, so that the switch unit 300 is in the conduction state.The positive pole of the power load 30 is connected to the power supply end 10 through the output end 20, the negative pole is connected to the ground through the switch unit 300, the loop is formed, and the load works normally.

[0069] When the voltage of the power supply end 10 exceeds the threshold voltage of the Zener diode, the Zener diode is reversely broken down and conducts.After the Zener diode conducts, the anode is at a low potential, and enough driving voltage is generated at the triggering end of the first switch tube Q1, so that the first switch tube Q1 conducts.After the first switch tube Q1 conducts, the voltage of the first on-off control end B2 of the switch unit 300 is pulled down, causing the switch unit 300 to turn off.After the switch unit 300 turns off, the connection between the negative pole of the power load 30 and the ground is cut off, the loop is interrupted, and thus the power load 30 is protected from overvoltage damage.

[0070] If the positive and negative poles of the power supply are connected reversely, the positive pole of the power supply is connected to the ground, and the negative pole is connected to the first collection end B1, the Zener diode cannot reach its breakdown voltage, and remains in the off state.

[0071] At this time, the first switch tube Q1 cannot be turned on, the first on-off control end B2 of the switch unit 300 is not affected, and the switch unit 300 remains in the off state. At this time, the negative pole of the power consumption load 30 cannot form a loop with the ground, thereby avoiding damage caused by reverse connection.

[0072] The beneficial effects of the technical scheme of the utility model lie in that the on-off control unit 100 composed of the cooperation of the Zener diode and the triode (or MOS tube) can efficiently detect the voltage of the power supply end 10 and realize accurate control, so that when the voltage of the power supply end 10 exceeds the preset threshold value, the communication of the load and the ground can be quickly cut off, and overvoltage damage is prevented.

[0073] Continuing to refer to Figure 2 In the embodiment, the on-off control unit 100 further comprises a voltage division module 200, and the anode of the voltage stabilizing device D1 is electrically connected to the trigger end of the first switch tube Q1 through the voltage division module 200.

[0074] In the embodiment, the cathode of the voltage stabilizing device D1 (Zener diode) is connected to the first collection end B1, and is used for monitoring the voltage of the power supply end 10. The anode is connected to the trigger end of the first switch tube Q1 through the voltage division module 200, and is reversely broken down and turned on when the voltage of the power supply end 10 exceeds the threshold value of the Zener diode.

[0075] The first switch tube Q1 can adopt a triode or a MOS tube, the trigger end of which receives the adjusted voltage signal through the voltage division module 200, one conducting end is connected to the first on-off control end B2, and the other conducting end is connected to the ground, and is used for controlling the conduction and the off of the switch unit 300.

[0076] The voltage division module 200 in the embodiment can be composed of two series resistors, one end of which is connected to the anode of the Zener diode, and the other end is connected to the ground. The voltage division point is connected to the trigger end of the first switch tube Q1, and is used for adjusting the conduction voltage of the Zener diode to adapt to the trigger voltage of the first switch tube Q1.

[0077] In the working process, when the voltage of the power supply end 10 is lower than the threshold value of the Zener diode, the Zener diode is cut off, the voltage division module 200 has no output voltage, the first switch tube Q1 remains in the off state, and the switch unit 300 is in the on state. The positive pole of the power consumption load 30 is connected to the power supply end 10 through the output end 20, the negative pole is connected to the ground through the switch unit 300, a loop is formed, and the load normally works.

[0078] When the voltage of the power supply end 10 exceeds the threshold value of the Zener diode, the Zener diode is broken down and turned on, and after being turned on, the voltage is adjusted to the trigger voltage of the first switch tube Q1 by the voltage division module 200, the first switch tube Q1 is turned on, the voltage of the first on-off control end B2 of the switching unit 300 is pulled low, and the switching unit 300 is turned off. At this time, the connection between the load 30 and the ground is cut off, the loop is interrupted, and damage to the load caused by overvoltage is avoided.

[0079] The voltage division module 200 adjusts the on-voltage of the Zener diode to adapt to the trigger requirements of the first switch tube Q1, ensuring reliable operation of the circuit. The influence of the on-voltage fluctuation of the Zener diode on the trigger performance of the first switch tube Q1 is effectively alleviated. In addition, by adjusting the resistance ratio of the voltage division module 200, different types of switch tubes can be adapted, expanding the practical application scenarios.

[0080] In some embodiments, the switching unit 300 includes a second switch tube Q2, the gate of the second switch tube Q2 is electrically connected to the second on-off control end B3, the first conduction end A3 of the second switch tube Q2 is electrically connected to the first connection end A1, and the second conduction end A4 of the second switch tube Q2 is grounded.

[0081] In this embodiment, the switching unit 300 can be implemented by using a second switch tube Q2, and the second switch tube Q2 can be an NMOS tube.

[0082] In the working process, when the voltage of the power supply end 10 is lower than the first threshold value, the gate of the second switch tube Q2 is directly electrically connected to the power supply end 10, so as to obtain a driving voltage. At this time, the second switch tube Q2 is turned on, a low-resistance path is formed between the first conduction end A3 and the second conduction end A4 of the second switch tube Q2, the negative electrode of the load 30 is grounded through the second switch tube Q2, a loop is formed between the load and the ground, and the load works normally.

[0083] When the voltage of the power supply end 10 is higher than the first threshold value, the Zener diode is reversely broken down and turned on, the power supply of the power supply end 10 is applied to the trigger end of the first switch tube Q1 through the voltage division module 200, the first switch tube Q1 is triggered and turned on, and one conduction end of the first switch tube Q1 is electrically connected to the gate of the second switch tube Q2. After the first switch tube Q1 is turned on, the voltage of the gate of the second switch tube Q2 is pulled low to near the ground potential. Since the gate of the second switch tube Q2 loses the driving voltage, the second switch tube Q2 changes from the on state to the off state. After the second switch tube Q2 is turned off, the connection loop between the negative electrode of the load 30 and the ground is cut off, thereby realizing the protection of the load 30 and avoiding damage caused by overvoltage.

[0084] The first switch tube Q1 and the second switch tube Q2 work together. When the voltage of the power supply end 10 exceeds the first threshold value, the conduction of the first switch tube Q1 can quickly pull down the gate voltage of the second switch tube Q2, so that the second switch tube Q2 is reliably cut off, thereby cutting off the connection between the load and the ground. When the voltage of the power supply end 10 is lower than the first threshold value, the conduction of the second switch tube Q2 forms a stable loop between the load and the ground, ensuring the normal operation of the electrical load 30.

[0085] Continuing to refer to Figure 2 In the embodiment, the switching unit 300 further includes a third switch tube Q3, the gate of the third switch tube Q3 is electrically connected to the second on-off control end B3, and the second conduction end A4 of the second switch tube Q2 is grounded through the third switch tube Q3.

[0086] In the embodiment, the switching unit 300 is further optimized by adding the third switch tube Q3, which works together with the second switch tube Q2.

[0087] In the normal working state, when the voltage of the power supply end 10 is lower than the first threshold value, the second on-off control end B3 is electrically connected to the power supply end 10, and the gate obtains a driving voltage. The second switch tube Q2 and the third switch tube Q3 are simultaneously turned on. The negative electrode of the electrical load 30 is grounded through the second switch tube Q2 and the third switch tube Q3, forming a complete loop, and the load works normally.

[0088] When the voltage of the power supply end 10 is higher than the first threshold value, the Zener diode is reversely broken down and conducts, and the first switch tube Q1 is driven through the voltage dividing module 200.

[0089] After the first switch tube Q1 is turned on, the voltage of the second on-off control end B3 is pulled down. The gates of the second switch tube Q2 and the third switch tube Q3 lose the driving voltage and are turned off. The connection between the negative electrode of the load and the ground is completely cut off, protecting the load from overvoltage damage.

[0090] By adding the third switch tube Q3 between the second switch tube Q2 and the ground, the loop reliability can be enhanced.

[0091] The third switch tube Q3 provides an additional grounding path for the load. Even if the second switch tube Q2 is not fully turned on under abnormal conditions, the third switch tube Q3 can still ensure the connection between the load and the ground.

[0092] At the same time, the current load can be shared by the parallel conduction of the second switch tube Q2 and the third switch tube Q3, reducing the power consumption and heat accumulation of a single switch tube and improving the overall reliability of the circuit.

[0093] In the overvoltage state, the two switch tubes are simultaneously turned off, forming a double circuit breaking effect, further ensuring the isolation between the load and the ground, and improving the protection effect.

[0094] Continuing to refer to Figure 2 In this embodiment, the protection circuit further comprises a transient voltage protection module 400, which comprises a transient voltage suppression device VR1, one end of which is electrically connected to the power supply end 10, and the release end is grounded.

[0095] In this embodiment, in order to enhance the safety and reliability of the protection circuit, the circuit adds a transient voltage protection module 400. This module can be composed of a TVS tube (Transient Voltage Suppressor). Specifically, when the input voltage of the power supply end 10 instantaneously rises (such as surge voltage caused by lightning strike, power supply switching or other sudden interference) beyond the breakdown voltage of the TVS tube, the TVS tube will quickly reverse breakdown and conduct. After the TVS tube is turned on, the transient high voltage is discharged to the ground through the TVS tube, protecting the subsequent circuit and the electrical load 30 from damage caused by high voltage impact.

[0096] Among them, the TVS tube has a response speed of nanoseconds, which can conduct and absorb energy in a very short time when the surge voltage appears, avoiding irreversible damage to the circuit caused by the surge.

[0097] During the surge voltage duration, the TVS tube clamps the voltage of the power supply end 10 near its breakdown voltage, preventing the voltage from rising further and stabilizing the working voltage range of the protection circuit.

[0098] Specifically, when the input voltage of the power supply end 10 is lower than the breakdown voltage of the TVS tube, the TVS tube is in a high resistance state and does not conduct, which has no effect on the normal operation of the circuit.

[0099] When the input voltage of the power supply end 10 exceeds the breakdown voltage of the TVS tube, the TVS tube immediately reverses and conducts, and the high voltage is discharged to the ground through the TVS tube, protecting sensitive components in the protection circuit from high voltage impact. After the surge ends, the input voltage returns to the normal range, and the TVS tube returns to the high resistance state, continuing to maintain the protection function of the circuit.

[0100] Through the rapid response and high energy absorption capacity of the TVS tube, the transient voltage protection module 400 can effectively protect the circuit from the impact of surge voltage and prolong the service life of the circuit.

[0101] Further, continuing to refer to Figure 2 , the transient voltage protection module 400 further comprises an electrostatic tube VR2, one end of which is electrically connected to the power supply end 10, and the other end is grounded.

[0102] To further improve the protection performance of the circuit, the transient voltage protection module 400 adds an electrostatic tube VR2 (ESD tube), which works together with the TVS tube to achieve comprehensive protection of the circuit.

[0103] When the circuit is working normally, the TVS tube and the static tube VR2 are both in a high resistance state, which does not affect the normal work of the circuit.

[0104] When the power end 10 is subjected to electrostatic discharge, the static tube VR2 will quickly conduct to discharge the electrostatic interference current to the ground, protecting the sensitive elements in the circuit. The reaction speed of the static tube VR2 is extremely fast (nanosecond level), which can cope with high-frequency electrostatic interference.

[0105] When the voltage of the power end 10 is raised due to external interference such as surge or lightning strike, exceeding the breakdown voltage of the TVS tube, the TVS tube will conduct in reverse breakdown. The TVS tube absorbs and discharges the high-voltage transient energy to the ground, preventing damage to the circuit.

[0106] The static tube VR2 and the TVS tube complement each other in protection mechanism: the static tube VR2 responds to high-frequency interference first, avoiding damage to the circuit by high-frequency interference; the TVS tube handles large-amplitude transient voltage, preventing damage to the circuit by surge or lightning strike.

[0107] In this way, the combination of the static tube VR2 and the TVS tube realizes multi-level protection against different types of transient high-voltage interference, improving the safety of the circuit. Both devices are common components, simple in structure and low in cost.

[0108] In summary, the combination of the static tube VR2 and the TVS tube in the transient voltage protection module 400 realizes comprehensive protection against transient interference of the power end 10, providing a more efficient and reliable protection mechanism for the electrical load 30.

[0109] Continuing to refer to Figure 2 In this embodiment, a filter circuit 500 is also included, which includes a third connection end A5 and a fourth connection end A6. The third connection end A5 is electrically connected to the transient voltage protection module 400 and the power end 10, and the fourth connection end A6 is electrically connected to the output end 20. The filter circuit 500 is used to filter the power input through the power end 10.

[0110] Specifically, the filter circuit 500 includes:

[0111] an inductor L1, one end of which is electrically connected to the third connection end A5, and the other end of which is electrically connected to the fourth connection end A6;

[0112] a capacitor CE1, one end of which is electrically connected to the other end of the inductor L1, and the other end of which is grounded.

[0113] To further optimize the performance of the circuit, the protection circuit also includes a filter circuit 500. The filter circuit 500 is used to filter the power input through the power end 10 to improve the quality of the power and reduce the interference to the load.

[0114] Specifically, the power supply end 10 inputs the power supply through the transient voltage protection module 400 and enters the filter circuit 500. At this time, the inductor L1 has an inhibitory effect on the change of current, can inhibit the passage of high-frequency interference signals, and has no significant effect on low-frequency or direct-current signals, so as to isolate high-frequency noise in the power supply end 10 and avoid entering the subsequent circuit.

[0115] The capacitor CE1 shows low impedance to high-frequency signals and can effectively bypass high-frequency interference signals and guide them to the ground, thereby smoothing the power supply voltage. The filter circuit 500 composed of the inductor L1 and the capacitor CE1 can form a low-pass filtering effect, allow stable direct-current or low-frequency signals to pass through, and filter out high-frequency interference in the power supply. In this way, by reducing high-frequency interference, the filter circuit 500 can effectively reduce the influence on sensitive elements in the subsequent circuit and prolong the service life of the circuit.

[0116] In summary, the embodiment increases the filter circuit 500, improves the anti-interference ability and power supply stability of the circuit, and provides a higher quality power supply environment for the power load 30.

[0117] The utility model further proposes an electronic equipment, including the protection circuit of preceding embodiment. The specific structure of this protection circuit refers to the above embodiment, because the electronic equipment adopts all the technical schemes of the above all embodiments, therefore at least has all the technical effects brought by the technical scheme of the above embodiment, here will not repeat.

[0118] In the embodiment, the electronic equipment can be a smart electronic equipment with a screen, such as a display screen, a smart photo frame, an advertising screen or a social companion device, etc. Specifically, it includes devices similar to "girlfriend machine", which usually has a touch screen, interactive function, and is designed for real-time photo sharing, video chat and other social scenes.

[0119] It can also include other electronic equipment that needs stable power supply, such as medical monitoring instruments, industrial control display terminals and portable multimedia devices, etc.

[0120] In the embodiment, when the input current exceeds the preset threshold, the protection circuit cuts off the loop between the power load 30 and the ground, effectively preventing damage to the equipment caused by overcurrent.

[0121] When the input voltage is higher than the preset value, the protection circuit cuts off the loop or absorbs excess energy to protect the internal elements of the electronic equipment from overvoltage impact. If the input power is connected in reverse, the protection circuit can block the reverse current to ensure that the device does not fail or is permanently damaged due to reverse connection.

[0122] The above only describes some or preferred embodiments of the present application, neither the text nor the drawings can limit the scope of protection of the present application, any equivalent structural transformation or direct / indirect application in other related technical fields under the concept of the whole present application and the contents of the present application and the drawings are included in the scope of protection of the present application.

Claims

1. A protection circuit applied to an electronic device, characterized in that, The protection circuit comprises: a power supply end; an output end for electrically connecting a positive electrode of an electrical load; an on-off control unit, the on-off control unit comprising a first collection end and a first on-off control end, the first collection end being electrically connected to the power supply end; a switch unit, the switch unit comprising a second on-off control end, a first connection end and a second connection end, the second on-off control end being electrically connected to the first on-off control end and the power supply end, the first connection end of the switch unit being used for electrically connecting a negative electrode of the electrical load, and the second connection end being grounded; a transient voltage protection module, the transient voltage protection module comprising a transient voltage suppression element, one end of the transient voltage suppression element being electrically connected to the power supply end, and a release end of the transient voltage suppression element being grounded; wherein the on-off control unit is configured to control the switch unit to work according to a voltage collected by the first collection end.

2. The protection circuit of claim 1, wherein The on-off control unit comprises a voltage stabilizing element, a cathode of the voltage stabilizing element being electrically connected to the first collection end; a first switch tube, a trigger end of the first switch tube being electrically connected to an anode of the voltage stabilizing element, one conduction end of the first switch tube being electrically connected to the first on-off control end, and the other conduction end being grounded.

3. The protection circuit of claim 2, wherein, The on-off control unit further comprises a voltage dividing module, the anode of the voltage stabilizing element being electrically connected to the trigger end of the first switch tube through the voltage dividing module.

4. The protection circuit according to any one of claims 1 to 3, characterized in that, The switch unit comprises a second switch tube, a gate of the second switch tube being electrically connected to the second on-off control end, a first conduction end of the second switch tube being electrically connected to the first connection end, and a second conduction end of the second switch tube being grounded.

5. The protection circuit of claim 4, wherein, The switch unit further comprises a third switch tube, a gate of the third switch tube being electrically connected to the second on-off control end, and the second conduction end of the second switch tube being grounded through the third switch tube.

6. The protection circuit of claim 1, wherein, The transient voltage protection module further comprises an electrostatic tube, one end of the electrostatic tube being electrically connected to the power supply end, and the other end being grounded.

7. The protection circuit of claim 1, wherein The protection circuit further comprises a filter circuit, the filter circuit comprising a third connection end and a fourth connection end, the third connection end being electrically connected to the transient voltage protection module and the power supply end, and the fourth connection end being electrically connected to the output end, the filter circuit being used for filtering a power supply input through the power supply end.

8. The protection circuit of claim 7, wherein, The filter circuit comprises: an inductor, one end of the inductor being electrically connected to the third connection end, and the other end of the inductor being electrically connected to the fourth connection end; a capacitor, one end of the capacitor being electrically connected to the other end of the inductor, and the other end of the capacitor being grounded.

9. An electronic device, comprising: The protection circuit comprises any one of claims 1 to 8.

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