Power supply protection circuit and electronic equipment

Abstract

The utility model discloses a power supply protection circuit and electronic equipment, which are applied to the field of power supply protection. The power supply protection circuit comprises a main coil circuit and an auxiliary coil circuit. The main coil circuit is coupled with the secondary coil circuit; the first end of the under-voltage protection circuit is connected with the first end of the main coil circuit, the second end of the under-voltage protection circuit is connected with the second end of the main coil circuit, the third end of the under-voltage protection circuit is connected with the third end of the main coil circuit, and the under-voltage protection circuit is used for controlling the main coil circuit to discharge when the output of the main coil circuit is in an under-voltage state; the first end of the overvoltage protection circuit is connected with the first end of the main coil circuit, the second end of the overvoltage protection circuit is connected with the third end of the main coil circuit, and the overvoltage protection circuit is used for performing overvoltage protection on the path with the highest output turn ratio in the secondary coil circuit and controlling the main coil circuit to discharge when the output of the main coil circuit is in an overvoltage state. Therefore, the method and the device are suitable for electronic equipment with relatively high power or relatively low power, and the application range is expanded.

Description

Technical Field

[0001] This utility model relates to the field of power supply protection, and in particular to a power supply protection circuit and electronic device. Background Technology

[0002] Currently, in electronic devices, short-circuit protection circuits for switching power supplies are typically designed. These circuits are used to reduce power output by sampling current or to restart the power supply by controlling the charging and discharging of the integrated circuit (IC) chip, thereby achieving the purpose of protection when the output is short-circuited.

[0003] However, this method can provide protection against short circuits for power supplies with lower power or better transformer manufacturing processes; for power supplies with higher power or poorer transformer winding, it can only provide short circuit protection in certain situations and may cause damage to the devices.

[0004] In view of the above-mentioned technologies, finding a power protection circuit is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to provide a power protection circuit and electronic device that can solve the problem of device damage caused by applying short-circuit protection circuits to power supplies with excessive power and poor transformer winding in the prior art.

[0006] To solve the above-mentioned technical problems, this utility model provides a power protection circuit, including: a power supply circuit, an undervoltage protection circuit, and an overvoltage protection circuit, wherein the power protection circuit includes a main coil circuit and a secondary coil circuit.

[0007] The main coil circuit is coupled to the secondary coil circuit.

[0008] The first terminal of the undervoltage protection circuit is connected to the first terminal of the main coil circuit, the second terminal of the undervoltage protection circuit is connected to the second terminal of the main coil circuit, and the third terminal of the undervoltage protection circuit is connected to the third terminal of the main coil circuit. It is used to control the main coil circuit to discharge when the output of the main coil circuit is in an undervoltage state.

[0009] The first terminal of the overvoltage protection circuit is connected to the first terminal of the main coil circuit, and the second terminal of the overvoltage protection circuit is connected to the third terminal of the main coil circuit. It is used to provide overvoltage protection for the output with the highest turns ratio in the secondary coil circuit when the output of the main coil circuit is in an overvoltage state, and to control the discharge of the main coil circuit.

[0010] Preferably, the undervoltage protection circuit includes: a first optocoupler, a first resistor, a second resistor, a third resistor, a first Zener diode, and a second Zener diode;

[0011] Among them, the first end of the first resistor is connected to the first end of the main coil circuit as the first end of the undervoltage protection circuit, and the second end of the first resistor is connected to the positive terminal of the first Zener diode.

[0012] The negative terminal of the first Zener diode is connected to the first terminal of the second resistor and the first terminal of the first optocoupler;

[0013] The second end of the second resistor is connected to the third end of the main coil circuit as the third end of the undervoltage protection circuit.

[0014] The second terminal of the first optocoupler is connected to the second terminal of the main coil circuit as the second terminal of the undervoltage protection circuit. The third terminal of the first optocoupler is connected to the first terminal of the third resistor. The fourth terminal of the first optocoupler is connected to the negative terminal of the second Zener diode.

[0015] The second terminal of the third resistor is connected to the first voltage source;

[0016] The positive terminal of the second Zener diode is grounded.

[0017] Preferably, the undervoltage protection circuit further includes: a first capacitor and a fourth resistor;

[0018] Wherein, the first terminal of the first capacitor is connected to the negative terminal of the first Zener diode, the first terminal of the second resistor and the first terminal of the first optocoupler, and the second terminal of the first capacitor is connected to the second terminal of the first optocoupler.

[0019] The first end of the fourth resistor is connected to the third end of the first optocoupler and the first end of the third resistor, and the second end of the fourth resistor is connected to the fourth end of the first optocoupler and the negative terminal of the second Zener diode.

[0020] Preferably, the overvoltage protection circuit includes: a second optocoupler, a fifth resistor, a sixth resistor, a third Zener diode, and a fourth Zener diode;

[0021] Among them, the first end of the fifth resistor is connected to the first end of the main coil circuit as the first end of the overvoltage protection circuit, and the second end of the fifth resistor is connected to the positive terminal of the third Zener diode.

[0022] The negative terminal of the third Zener diode is connected to the first terminal of the second optocoupler;

[0023] The second end of the second optocoupler is connected to the third end of the main coil circuit as the second end of the overvoltage protection circuit. The third end of the second optocoupler is connected to the first end of the sixth resistor. The fourth end of the second optocoupler is connected to the negative terminal of the fourth Zener diode.

[0024] The second terminal of the sixth resistor is connected to the second voltage source;

[0025] The positive terminal of the fourth Zener diode is grounded.

[0026] Preferably, the overvoltage protection circuit further includes: a seventh resistor;

[0027] Among them, the first end of the seventh resistor is connected to the third end of the second optocoupler and the first end of the sixth resistor;

[0028] The second terminal of the seventh resistor is connected to the fourth terminal of the second optocoupler and the negative terminal of the fourth Zener diode.

[0029] Preferably, the main coil circuit includes: a main coil winding, a first auxiliary winding, an integrated control chip, a MOSFET, a first transistor, a second transistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor;

[0030] The first end of the main coil winding serves as the input terminal of the main coil circuit and is connected to the first end of the integrated control chip. The second end of the main coil winding is connected to the source of the MOSFET.

[0031] The gate of the MOSFET is connected to the second terminal of the integrated control chip, and the drain of the MOSFET is connected to the third terminal of the integrated control chip and the first terminal of the eighth resistor.

[0032] The second terminal of the eighth resistor is connected to the fourth terminal of the integrated control chip and the first terminal of the first auxiliary winding, and is grounded;

[0033] The fifth terminal of the integrated control chip is connected to the third terminal of the main coil circuit, the third terminal of the undervoltage protection circuit, and the second terminal of the overvoltage protection circuit.

[0034] The second end of the first auxiliary winding is connected to the first end of the ninth resistor;

[0035] The second terminal of the ninth resistor is connected to the first terminal of the tenth resistor and the first terminal of the eleventh resistor.

[0036] The second end of the tenth resistor is connected to the base of the first transistor and the collector of the second transistor;

[0037] The second terminal of the eleventh resistor is connected to the emitter of the first transistor;

[0038] The collector of the first transistor is connected to the base of the second transistor and the first end of the twelfth resistor, and together they are connected to the first end of the main coil circuit, the first end of the undervoltage protection circuit, and the first end of the overvoltage protection circuit.

[0039] The emitter of the second transistor is connected to the second terminal of the twelfth resistor and grounded, and together they serve as the second terminal of the main coil circuit and are connected to the second terminal of the undervoltage protection circuit.

[0040] Preferably, the main coil circuit further includes: a first diode, a thirteenth resistor, and a second capacitor;

[0041] In this circuit, the positive terminal of the first diode serves as the input terminal of the main coil circuit, and the negative terminal of the first diode is connected to the first terminal of the thirteenth resistor and the first terminal of the main coil winding.

[0042] The second terminal of the thirteenth resistor is connected to the first terminal of the integrated control chip and the first terminal of the second capacitor.

[0043] The second terminal of the second capacitor is grounded.

[0044] Preferably, the main coil circuit further includes: a second diode and a fourteenth resistor;

[0045] The negative terminal of the second diode is connected to the first terminal of the ninth resistor, and the positive terminal of the second diode is connected to the first terminal of the fourteenth resistor.

[0046] The second end of the fourteenth resistor is connected to the second end of the first auxiliary winding.

[0047] Preferably, the secondary coil circuit includes: a secondary coil winding, a second auxiliary winding, a third diode, a fourth diode, a third capacitor, and a fourth capacitor;

[0048] The first end of the secondary coil winding is connected to the positive terminal of the third diode;

[0049] The negative terminal of the third diode is connected to the first terminal of the third capacitor and the first voltage source;

[0050] The second terminal of the secondary coil winding is connected to the second terminal of the third capacitor and grounded;

[0051] The first end of the second auxiliary winding is connected to the positive terminal of the fourth diode;

[0052] The cathode of the fourth diode is connected to the first terminal of the fourth capacitor and the second voltage source;

[0053] The second terminal of the second auxiliary winding is connected to the second terminal of the fourth capacitor and grounded.

[0054] On the other hand, this application also provides an electronic device including the power protection circuit described above.

[0055] This utility model provides a power protection circuit that adds undervoltage protection and overvoltage protection circuits to the initial power supply circuit. The undervoltage protection circuit adds undervoltage control to the main output of the power supply circuit, enabling rapid discharge of the main coil circuit to achieve protection. The overvoltage protection circuit adds overvoltage control to the main output of the power supply circuit. When the power supply circuit output feedback is abnormal, overvoltage protection is applied to the output of the secondary coil circuit with the highest turns ratio. When the voltage rises abnormally rapidly in that circuit, rapid discharge of the main coil circuit achieves protection. Therefore, this application adds peripheral circuits for undervoltage and overvoltage protection, effectively achieving protection, reducing device damage, and offering a simple and low-cost implementation. Based on this, this application is applicable to electronic devices with both high and low power, expanding the application range of power protection circuits. Attached Figure Description

[0056] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A structural diagram of a power protection circuit provided in an embodiment of this application;

[0058] Figure 2 A circuit diagram of the undervoltage protection circuit provided in the embodiments of this application;

[0059] Figure 3 A circuit diagram of the overvoltage protection circuit provided in the embodiments of this application;

[0060] Figure 4 A circuit diagram of a power protection circuit provided in an embodiment of this application. Detailed Implementation

[0061] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0062] The core of this invention is to provide a power protection circuit and an electronic device.

[0063] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] Figure 1 A structural diagram of a power protection circuit provided in this application embodiment includes: a power supply circuit 1, an undervoltage protection circuit 2, and an overvoltage protection circuit 3. The power supply protection circuit 1 includes a main coil circuit 11 and a secondary coil circuit 12. The circuit connections are as follows: the main coil circuit 11 is coupled to the secondary coil circuit 12; the first terminal of the undervoltage protection circuit 2 is connected to the first terminal of the main coil circuit 11, the second terminal of the undervoltage protection circuit 2 is connected to the second terminal of the main coil circuit 11, and the third terminal of the undervoltage protection circuit 2 is connected to the third terminal of the main coil circuit 11; the first terminal of the overvoltage protection circuit 3 is connected to the first terminal of the main coil circuit 11, and the second terminal of the overvoltage protection circuit 3 is connected to the third terminal of the main coil circuit 11.

[0065] In a specific embodiment, the power supply circuit 1 is a conventional power supply circuit, providing power to peripheral circuits, etc. Based on this, this application adds an undervoltage protection circuit 2 and an overvoltage protection circuit 3.

[0066] Among them, for the undervoltage protection circuit 2, undervoltage control is added to the main output of the power supply. When the main coil circuit 11 is undervoltage, the voltage in the main coil circuit 11 is too low. Therefore, by connecting the undervoltage control circuit 2 with the main coil circuit 11, the main coil circuit 11 is controlled to discharge quickly, thereby achieving the purpose of undervoltage protection.

[0067] For the overvoltage protection circuit 3, overvoltage control is added to the main output of the power supply. When the main coil circuit 11 experiences an overvoltage, the voltage in the main coil circuit 11 increases. Then, overvoltage protection is applied to the output of the secondary coil circuit 12 with the highest turns ratio. When the voltage rises abnormally and rapidly, the connection between the overvoltage control circuit 3 and the main coil circuit 11 controls the main coil circuit 11 to discharge rapidly, thereby achieving the purpose of overvoltage protection.

[0068] It should be noted that the main coil circuit 11 and the auxiliary coil circuit 12 in the power supply circuit 1 are existing technologies, and therefore this application does not limit their specific structures.

[0069] It should also be noted that this application does not limit the specific structure of the undervoltage protection circuit 2 and the overvoltage protection circuit 3, as long as they meet the above functions.

[0070] Therefore, the power supply protection circuit provided by this utility model includes: a power supply circuit, an undervoltage protection circuit, and an overvoltage protection circuit. The power supply protection circuit includes a main coil circuit and a secondary coil circuit; the main coil circuit and the secondary coil circuit are coupled. The first terminal of the undervoltage protection circuit is connected to the first terminal of the main coil circuit, the second terminal of the undervoltage protection circuit is connected to the second terminal of the main coil circuit, and the third terminal of the undervoltage protection circuit is connected to the third terminal of the main coil circuit. This is used to control the main coil circuit to discharge when its output is in an undervoltage state. The first terminal of the overvoltage protection circuit is connected to the first terminal of the main coil circuit, and the second terminal of the overvoltage protection circuit is connected to the third terminal of the main coil circuit. This is used to provide overvoltage protection to the secondary coil circuit with the highest output turns ratio when its output is in an overvoltage state, and to control the main coil circuit to discharge. Therefore, this application adds an undervoltage protection circuit and an overvoltage protection circuit to the initial power supply circuit. The undervoltage protection circuit adds undervoltage control to the main output of the power supply circuit, enabling rapid discharge of the main coil circuit and thus achieving protection. The overvoltage protection circuit adds overvoltage control to the main output of the power supply circuit. When the power supply circuit output feedback is abnormal, overvoltage protection is applied to the output of the secondary coil circuit with the highest turns ratio. When the voltage rises abnormally rapidly in that circuit, rapid discharge of the main coil circuit achieves protection. Therefore, this application is applicable to electronic devices with both high and low power, expanding the scope of application of power supply protection circuits.

[0071] In specific embodiments, such as Figure 2 As shown, the undervoltage protection circuit 2 includes: a first optocoupler U1, a first resistor R1, a second resistor R2, a third resistor R3, a first Zener diode TD1, a second Zener diode TD2, a first capacitor C1, and a fourth resistor R4. The circuit connections are as follows: the first end of the first resistor R1 is connected to the first end of the main coil circuit 11 as the first end of the undervoltage protection circuit 2; the second end of the first resistor R1 is connected to the positive terminal of the first Zener diode TD1; the negative terminal of the first Zener diode TD1 is connected to the first end of the second resistor R2, the first end of the first capacitor C1, and the first end of the first optocoupler U1; the second end of the second resistor R2 is connected to the third end of the main coil circuit 11 as the third end of the undervoltage protection circuit 2; the second end of the first optocoupler U1 is connected to the second end of the first capacitor C1, and together they serve as the second end of the undervoltage protection circuit 2 connected to the second end of the main coil circuit 11; the third end of the first optocoupler U1 is connected to the first end of the third resistor R3 and the first end of the fourth resistor R4; the fourth end of the first optocoupler U1 is connected to the negative terminal of the second Zener diode TD1 and the second end of the fourth resistor R4; the second end of the third resistor R3 is connected to the first voltage source VCC1; and the positive terminal of the second Zener diode TD2 is grounded.

[0072] In a specific embodiment, the first and second terminals of the undervoltage protection circuit 2 are connected to the first and second terminals of the main coil circuit 11 in the power supply circuit 1, respectively. The output of the main coil circuit 11 is detected mainly through these two connected terminals. If the voltage in the main coil circuit 11 is too low, it indicates that the circuit is currently in an undervoltage condition. At this time, the first optocoupler U1 will operate accordingly, controlling the main coil circuit 11 to discharge rapidly through the third terminal of the main coil circuit 11, thereby achieving the purpose of undervoltage protection.

[0073] In the undervoltage protection circuit 2, the resistors (first resistor R1, second resistor R2, third resistor R3 and fourth resistor R4) and capacitors (first capacitor C1) serve as voltage dividers and filters; the Zener diodes (first Zener diode TD1 and second Zener diode TD2) serve as voltage regulators.

[0074] In specific embodiments, such as Figure 3 As shown, the overvoltage protection circuit 3 includes: a second optocoupler U2, a fifth resistor R5, a sixth resistor R6, a third Zener diode TD3, a fourth Zener diode TD4, and a seventh resistor R7. The circuit connections are as follows: the first terminal of the fifth resistor R5 is connected to the first terminal of the main coil circuit 11 as the first terminal of the overvoltage protection circuit 3; the second terminal of the fifth resistor R5 is connected to the positive terminal of the third Zener diode TD3; the negative terminal of the third Zener diode TD3 is connected to the first terminal of the second optocoupler U2; the second terminal of the second optocoupler U2 is connected to the third terminal of the main coil circuit 11 as the second terminal of the overvoltage protection circuit 3; the third terminal of the second optocoupler U2 is connected to the first terminals of the sixth resistor R6 and the seventh resistor R7; the fourth terminal of the second optocoupler U2 is connected to the negative terminal of the fourth Zener diode TD4 and the second terminal of the seventh resistor R7; the second terminal of the sixth resistor R6 is connected to the second voltage source VCC2; and the positive terminal of the fourth Zener diode TD4 is grounded.

[0075] In a specific embodiment, the first terminal of the overvoltage protection circuit 3 is connected to the first terminal of the main coil circuit 11 in the power supply circuit 1. This connection is mainly used to detect the output of the main coil circuit 11. If an overvoltage occurs in the main coil circuit 11, it indicates that an overvoltage condition is currently in effect. At this time, the second optocoupler U2 will operate accordingly, controlling the main coil circuit 11 to discharge rapidly through the third terminal of the main coil circuit 11, thereby achieving the purpose of overvoltage protection.

[0076] In the overvoltage protection circuit 3, the resistors (the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7) serve as voltage dividers and filters; the Zener diodes (the third Zener diode TD3 and the fourth Zener diode TD4) serve as voltage regulators.

[0077] It should be noted that the embodiments provided in this application are only one possible implementation method, but are not limited to this only implementation method. Users can set their own implementation methods according to their needs.

[0078] The specific structures of the undervoltage protection circuit and overvoltage protection circuit provided in the above embodiments of this application can realize overvoltage protection and undervoltage protection of the power supply circuit. Moreover, the circuit implementation under this structure is simple and has a low cost.

[0079] In specific embodiments, such as Figure 4As shown, its main coil 11 circuit includes: main coil winding L1, first auxiliary winding L2, integrated control chip U3, MOSFET Q1, first transistor Q2, second transistor Q3, eighth resistor R8, ninth resistor R9, tenth resistor R10, eleventh resistor R11, twelfth resistor R12, first diode D1, thirteenth resistor R13, second capacitor C2, second diode D2 and fourteenth resistor R14. The circuit connections are as follows: the anode of the first diode D1 serves as the input terminal of the main coil circuit 11; the cathode of the first diode D1 is connected to the first terminal of the thirteenth resistor R13, the first terminal of the main coil winding L1, and the first terminal (VCC) of the integrated control chip U3; the second terminal of the thirteenth resistor R13 is connected to the first terminal of the integrated control chip U3 and the first terminal of the second capacitor C2; the second terminal of the second capacitor C2 is grounded; the cathode of the second diode D2 is connected to the first terminal of the ninth resistor R9; the anode of the second diode D2 is connected to the first terminal of the fourteenth resistor R14; the second terminal of the fourteenth resistor R14 is connected to the second terminal of the first auxiliary winding L2; the second terminal of the main coil winding L1 is connected to the source of the MOSFET Q1; the gate of the MOSFET Q1 is connected to the second terminal of the integrated control chip U3; the drain of the MOSFET Q1 is connected to the third terminal of the integrated control chip U3 and the first terminal of the eighth resistor R8; the second terminal of the eighth resistor R8 is connected to the second terminal of the integrated control chip U3. The fourth terminal is connected to the first terminal of the first auxiliary winding L2 and grounded; the fifth terminal (REF) of the integrated control chip U3 is connected to the third terminal of the main coil circuit 11, the third terminal of the undervoltage protection circuit 2, and the second terminal of the overvoltage protection circuit 3; the second terminal of the ninth resistor R9 is connected to the first terminal of the tenth resistor R10 and the first terminal of the eleventh resistor R11; the second terminal of the tenth resistor R10 is connected to the base of the first transistor Q2 and the collector of the second transistor Q3; the second terminal of the eleventh resistor R11 is connected to the emitter of the first transistor Q2; the collector of the first transistor Q2 is connected to the base of the second transistor Q3 and the first terminal of the twelfth resistor R12, and together they are connected to the first terminal of the main coil circuit 11, the first terminal of the undervoltage protection circuit 2, and the first terminal of the overvoltage protection circuit 3; the emitter of the second transistor Q3 is connected to the second terminal of the twelfth resistor R12 and grounded, and together they are connected to the second terminal of the main coil circuit 11, the second terminal of the undervoltage protection circuit 2.

[0080] like Figure 4As shown, its secondary coil circuit 12 includes: a secondary coil winding L3, a second auxiliary winding L4, a third diode D3, a fourth diode D4, a third capacitor C3, and a fourth capacitor C4. The circuit connections are as follows: the first terminal of the secondary coil winding L3 is connected to the positive terminal of the third diode D3; the negative terminal of the third diode D3 is connected to the first terminal of the third capacitor C3 and the first voltage source VCC1; the second terminal of the secondary coil winding L3 is connected to the second terminal of the third capacitor C3 and grounded; the first terminal of the second auxiliary winding L4 is connected to the positive terminal of the fourth diode D4; the negative terminal of the fourth diode D4 is connected to the first terminal of the fourth capacitor C4 and the second voltage source VCC2; the second terminal of the second auxiliary winding L4 is connected to the second terminal of the fourth capacitor C4 and grounded.

[0081] In a specific embodiment, the main coil circuit 11 serves as the input of the power supply circuit 1, while the secondary coil circuit 12 serves as the output of the power supply circuit 1. The main coil circuit 11 is coupled to the secondary coil winding L3 and the second auxiliary winding L4 in the secondary coil circuit 12 through the main coil winding L1 and the first auxiliary winding L2.

[0082] For the main coil 11 circuit, its integrated control chip U3 is the main component, used to provide power and discharge; MOSFET Q1, first transistor Q2 and second transistor Q3 mainly act as switches, determining whether the current path is conducting based on the voltage at the three terminals; resistors (eighth resistor R8, ninth resistor R9, tenth resistor R10, eleventh resistor R11, twelfth resistor R12, thirteenth resistor R13 and fourteenth resistor R14) and capacitor (second capacitor C2) are used for voltage division and filtering; diodes (first diode D1 and second diode D2) enable unidirectional conduction of the circuit.

[0083] For the secondary coil circuit 12, its capacitors (third capacitor C3 and fourth capacitor C4) are used for voltage division and filtering; the diodes (third diode D3 and fourth diode D4) are used for unidirectional conduction of the circuit.

[0084] It should be noted that the embodiments provided in this application are only one possible implementation method, but are not limited to this only implementation method. Users can set their own implementation methods according to their needs.

[0085] Therefore, the power protection circuit provided in this application has the following advantages:

[0086] 1. Adding overvoltage protection circuits and undervoltage protection circuits can effectively achieve the protection purpose, reduce component damage, and is simple to implement and low in cost;

[0087] 2. When the main coil circuit feedback is abnormal, overvoltage protection is achieved through the secondary coil circuit with a larger turns ratio, reducing device damage. The implementation method is simple, reliable, and low in cost.

[0088] On the other hand, this application also provides an electronic device with the aforementioned power protection circuit, and has the same beneficial effects.

[0089] Since the embodiments of the electronic devices provided in this application are the same as the embodiments of the power protection circuit described above, this application will not repeat them here.

[0090] The power protection circuit and electronic device provided by this utility model have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

[0091] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A power supply protection circuit, characterized in that, include: The circuit includes a power supply circuit, an undervoltage protection circuit, and an overvoltage protection circuit, wherein the power supply protection circuit includes a main coil circuit and a secondary coil circuit. The main coil circuit is coupled to the secondary coil circuit. The first terminal of the undervoltage protection circuit is connected to the first terminal of the main coil circuit, the second terminal of the undervoltage protection circuit is connected to the second terminal of the main coil circuit, and the third terminal of the undervoltage protection circuit is connected to the third terminal of the main coil circuit. It is used to control the main coil circuit to discharge when the output of the main coil circuit is in an undervoltage state. The first terminal of the overvoltage protection circuit is connected to the first terminal of the main coil circuit, and the second terminal of the overvoltage protection circuit is connected to the third terminal of the main coil circuit. When the output of the main coil circuit is in an overvoltage state, the circuit with the highest output turns ratio in the secondary coil circuit is protected against overvoltage, and the main coil circuit is controlled to discharge.

2. The power protection circuit according to claim 1, characterized in that, The undervoltage protection circuit includes: a first optocoupler, a first resistor, a second resistor, a third resistor, a first Zener diode, and a second Zener diode. Wherein, the first end of the first resistor is connected to the first end of the main coil circuit as the first end of the undervoltage protection circuit, and the second end of the first resistor is connected to the positive terminal of the first Zener diode. The negative terminal of the first Zener diode is connected to the first terminal of the second resistor and the first terminal of the first optocoupler; The second end of the second resistor is connected to the third end of the main coil circuit as the third end of the undervoltage protection circuit. The second end of the first optocoupler is connected to the second end of the main coil circuit as the second end of the undervoltage protection circuit, the third end of the first optocoupler is connected to the first end of the third resistor, and the fourth end of the first optocoupler is connected to the negative terminal of the second Zener diode. The second terminal of the third resistor is connected to the first voltage source; The positive terminal of the second Zener diode is grounded.

3. The power protection circuit according to claim 2, characterized in that, The undervoltage protection circuit further includes: a first capacitor and a fourth resistor; Wherein, the first terminal of the first capacitor is connected to the negative terminal of the first Zener diode, the first terminal of the second resistor and the first terminal of the first optocoupler, and the second terminal of the first capacitor is connected to the second terminal of the first optocoupler. The first end of the fourth resistor is connected to the third end of the first optocoupler and the first end of the third resistor, and the second end of the fourth resistor is connected to the fourth end of the first optocoupler and the negative terminal of the second Zener diode.

4. The power protection circuit according to claim 1, characterized in that, The overvoltage protection circuit includes: a second optocoupler, a fifth resistor, a sixth resistor, a third Zener diode, and a fourth Zener diode; Wherein, the first end of the fifth resistor is connected to the first end of the main coil circuit as the first end of the overvoltage protection circuit, and the second end of the fifth resistor is connected to the positive terminal of the third Zener diode; The negative terminal of the third Zener diode is connected to the first terminal of the second optocoupler; The second end of the second optocoupler is connected to the third end of the main coil circuit as the second end of the overvoltage protection circuit, the third end of the second optocoupler is connected to the first end of the sixth resistor, and the fourth end of the second optocoupler is connected to the negative terminal of the fourth Zener diode. The second terminal of the sixth resistor is connected to the second voltage source; The positive terminal of the fourth Zener diode is grounded.

5. The power protection circuit according to claim 4, characterized in that, The overvoltage protection circuit further includes: a seventh resistor; The first end of the seventh resistor is connected to the third end of the second optocoupler and the first end of the sixth resistor; The second end of the seventh resistor is connected to the fourth end of the second optocoupler and the negative terminal of the fourth Zener diode.

6. The power protection circuit according to claim 1, characterized in that, The main coil circuit includes: a main coil winding, a first auxiliary winding, an integrated control chip, a MOSFET, a first transistor, a second transistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor. Wherein, the first end of the main coil winding serves as the input end of the main coil circuit and is connected to the first end of the integrated control chip, and the second end of the main coil winding is connected to the source of the MOS transistor; The gate of the MOS transistor is connected to the second terminal of the integrated control chip, and the drain of the MOS transistor is connected to the third terminal of the integrated control chip and the first terminal of the eighth resistor. The second end of the eighth resistor is connected to the fourth end of the integrated control chip and the first end of the first auxiliary winding, and is grounded; The fifth terminal of the integrated control chip serves as the third terminal of the main coil circuit and is connected to the third terminal of the undervoltage protection circuit and the second terminal of the overvoltage protection circuit. The second end of the first auxiliary winding is connected to the first end of the ninth resistor; The second end of the ninth resistor is connected to the first end of the tenth resistor and the first end of the eleventh resistor; The second end of the tenth resistor is connected to the base of the first transistor and the collector of the second transistor; The second end of the eleventh resistor is connected to the emitter of the first transistor; The collector of the first transistor is connected to the base of the second transistor and the first end of the twelfth resistor, and together they are connected to the first end of the main coil circuit, the first end of the undervoltage protection circuit, and the first end of the overvoltage protection circuit. The emitter of the second transistor is connected to the second terminal of the twelfth resistor and grounded, and together they serve as the second terminal of the main coil circuit and are connected to the second terminal of the undervoltage protection circuit.

7. The power protection circuit according to claim 6, characterized in that, The main coil circuit also includes: a first diode, a thirteenth resistor, and a second capacitor; Wherein, the positive terminal of the first diode serves as the input terminal of the main coil circuit, and the negative terminal of the first diode is connected to the first terminal of the thirteenth resistor and the first terminal of the main coil winding. The second end of the thirteenth resistor is connected to the first end of the integrated control chip and the first end of the second capacitor. The second terminal of the second capacitor is grounded.

8. The power protection circuit according to claim 7, characterized in that, The main coil circuit also includes: a second diode and a fourteenth resistor; The negative terminal of the second diode is connected to the first terminal of the ninth resistor, and the positive terminal of the second diode is connected to the first terminal of the fourteenth resistor. The second end of the fourteenth resistor is connected to the second end of the first auxiliary winding.

9. The power protection circuit according to any one of claims 1-8, characterized in that, The secondary coil circuit includes: a secondary coil winding, a second auxiliary winding, a third diode, a fourth diode, a third capacitor, and a fourth capacitor; The first end of the secondary coil winding is connected to the positive terminal of the third diode; The negative terminal of the third diode is connected to the first terminal of the third capacitor and the first voltage source; The second end of the secondary coil winding is connected to the second end of the third capacitor and grounded; The first end of the second auxiliary winding is connected to the positive terminal of the fourth diode; The negative terminal of the fourth diode is connected to the first terminal of the fourth capacitor and the second voltage source. The second end of the second auxiliary winding is connected to the second end of the fourth capacitor and grounded.

10. An electronic device, characterized in that, Includes the power protection circuit as described in any one of claims 1-9.

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