Coupler and switching power supply circuit

Abstract

This application discloses a coupler and a switching power supply circuit, relating to the field of coupler technology. The coupler includes a substrate, auxiliary pins, and a housing. The auxiliary pins include a first pin, a second pin, a third pin, a fourth pin, a fifth pin, and a sixth pin. A first gap is provided between the first pin and the second pin, a second gap is provided between the third pin and the fourth pin, and a third gap is provided between the fifth pin and the sixth pin, wherein the third gap is the smallest. The housing includes multiple terminals, and the first pin, the second pin, the third pin, the fourth pin, the fifth pin, and the sixth pin correspond one-to-one with the multiple terminals. The first pin, the second pin, the third pin, the fourth pin, the fifth pin, and the sixth pin are all located in the corresponding terminals. This application sets the fifth pin and the sixth pin as discharge pins to achieve discharge of electrostatic discharge, thereby protecting the circuit, extending the service life of components, and reducing the production cost of the product.

Description

Technical Field

[0001] This application relates to the field of coupler technology, and in particular to a coupler and a switching power supply circuit. Background Technology

[0002] In the existing technology, during ESD electrostatic discharge testing, the ESD electrostatic discharge may cause abnormal electrostatic discharge at the primary and secondary ends of the coupler, which may damage the components connected to the coupler, reduce product quality, and increase product production costs. Utility Model Content

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a coupler and switching power supply circuit with an electrostatic discharge pin, which can discharge static electricity to ground, thereby protecting the device and reducing production costs.

[0004] The coupler according to a first aspect embodiment of this application includes: a substrate; auxiliary pins, the auxiliary pins including a first pin, a second pin, a third pin, a fourth pin, a fifth pin, and a sixth pin, wherein the first pin and the second pin are mirror images of each other on opposite sides of the substrate along the central axis of the substrate, the third pin and the fourth pin are mirror images of each other on opposite sides of the substrate along the central axis of the substrate, and the fifth pin and the sixth pin are mirror images of each other on opposite sides of the substrate along the central axis of the substrate, wherein the first pin, the third pin, and the fifth pin are located on the same side of the substrate, a first spacing is provided between the first pin and the second pin, and the third pin and the sixth pin are... A second spacing is provided between the four pins, and a third spacing is provided between the fifth pin and the sixth pin, wherein the third spacing is smaller than the second spacing and the third spacing is smaller than the first spacing; the housing includes multiple terminals, and the substrate, the first pin, the second pin, the third pin, the fourth pin, the fifth pin and the sixth pin are encapsulated in the housing, and the first pin, the second pin, the third pin, the fourth pin, the fifth pin and the sixth pin correspond one-to-one with the multiple terminals, and the first pin, the second pin, the third pin, the fourth pin, the fifth pin and the sixth pin are all disposed in the corresponding terminals.

[0005] The coupler according to the embodiments of this application has at least the following beneficial effects: the substrate facilitates the carrying of circuits, and the first, second, third, and fourth pins facilitate the establishment of connections between the coupler and other devices, such as feedback modules and control modules. The fifth and sixth pins facilitate the coupler to perform electrostatic discharge operations on the applied circuit, thereby discharging static electricity to ground, thus protecting the coupler and the devices connected to the primary and secondary ends of the coupler and avoiding unnecessary risks. The third spacing is set to be smaller than the first and second spacings, making the third spacing the shortest spacing, thereby ensuring that electrostatic discharge operations are preferentially performed through the fifth and sixth pins, thus protecting the other devices and extending the service life of the circuit. The housing protects the substrate and auxiliary pins to a certain extent, and also prevents impurities from covering the fifth and sixth pins, thereby affecting the discharge effect.

[0006] According to some embodiments of this application, the first spacing is equal to the second spacing.

[0007] According to some embodiments of this application, the third spacing is 1.5 mm shorter than the second spacing.

[0008] The switching power supply circuit according to a second aspect embodiment of this application includes:

[0009] The coupler of the first aspect of the embodiments of this application.

[0010] The switching power supply circuit according to the embodiments of this application has at least the following beneficial effects: the substrate facilitates the carrying of the circuit, and the first, second, third, and fourth pins facilitate the connection between the coupler and other devices, such as feedback modules and control modules. The fifth and sixth pins facilitate the coupler to perform electrostatic discharge operation on the applied circuit, thereby discharging the static electricity to the ground, thus protecting the coupler and the devices connected to the primary and secondary ends of the coupler and avoiding unnecessary risks. The third spacing is set to be smaller than the first and second spacings, making the third spacing the shortest spacing, thereby ensuring that electrostatic discharge operation is preferentially performed through the fifth and sixth pins, thus protecting the other devices and extending the service life of the circuit. The housing protects the substrate and auxiliary pins to a certain extent, and also prevents impurities from covering the fifth and sixth pins, thereby affecting the discharge effect. By introducing the coupler of this application, the switching power supply circuit of this application has higher stability and better ensures the user experience.

[0011] According to some embodiments of this application, it further includes a control module and a feedback module. One end of the control module is connected to a power source, and the other end is connected to one end of a transformer. The transformer is used to boost or buck the voltage output by the control module. The input end of the feedback module is connected to the other end of the transformer, and the output end of the feedback module is connected to the control module through the coupler. The fifth pin is connected to the input end of the feedback module, and the sixth pin is grounded. The fifth pin and the sixth pin are used to discharge the static electricity generated by the switching power supply circuit to the ground.

[0012] According to some embodiments of this application, a rectifier bridge is also included, through which the control module is connected to the power supply, and the rectifier bridge is used to convert the input AC power into DC power and output it to the control module.

[0013] According to some embodiments of this application, a filter is also included, one end of which is connected to the output terminal of the rectifier bridge, and the other end of which is connected to the input terminal of the control module.

[0014] According to some embodiments of this application, a fuse is also included, and the first output terminal of the power supply is connected to the first input terminal of the rectifier bridge through the fuse.

[0015] According to some embodiments of this application, a thermistor is also included, and the second output terminal of the power supply is connected to the second input terminal of the rectifier bridge through the thermistor.

[0016] According to some embodiments of this application, the control module includes a pulse width modulation control unit and a field-effect transistor control unit. One end of the pulse width modulation control unit is used to connect to the power supply, and the other end of the pulse width modulation control unit is connected to one end of the field-effect transistor control unit. The other end of the field-effect transistor control unit is connected to the transformer.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of a coupler without a housing according to an embodiment of this application;

[0020] Figure 2 This is a schematic diagram of the housing according to an embodiment of this application;

[0021] Figure 3This is a schematic diagram of a switching power supply circuit according to an embodiment of this application.

[0022] Figure label:

[0023] Housing 100; Terminal 101. Detailed Implementation

[0024] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0025] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0026] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0027] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0028] Currently, the use of coupler OP1 is quite common in some circuits that require isolation or AC / DC primary-secondary conversion. However, in ESD discharge electrostatic testing, repeated tests can cause the accumulated electrostatic charge to produce abnormal electrostatic discharge phenomena at the primary and secondary terminals of coupler OP1, which in turn damages the components connected to the primary and secondary terminals of coupler OP1, increasing the frequency of component replacement and raising the production cost of the product.

[0029] Based on this, this application proposes a coupler OP1 and a switching power supply circuit, which aims to form an electrostatic discharge circuit by setting electrostatic discharge discharge pins, namely the fifth pin 5 and the sixth pin 6, on the coupler OP1, thereby discharging the electrostatic discharge pins to the circuit and achieving the purpose of protecting the circuit, avoiding damage to the components connected to the coupler OP1, extending the service life of the components, and reducing production costs.

[0030] It is understood that the coupler OP1 of this application includes a substrate, auxiliary pins, and a housing 100. The auxiliary pins include a first pin 1, a second pin 2, a third pin 33, a fourth pin 44, a fifth pin 5, and a sixth pin 6. The first pin 1 and the second pin 2 are mirror images of each other on opposite sides of the substrate along the central axis. The third pin 33 and the fourth pin 44 are mirror images of each other on opposite sides of the substrate along the central axis. The fifth pin 5 and the sixth pin 6 are mirror images of each other on opposite sides of the substrate along the central axis. The first pin 1, the third pin 33, and the fifth pin 5 are located on the same side of the substrate. A first spacing is provided between the first pin 1 and the second pin 2. A second spacing is provided between the third pin 33 and the fourth pin 44, and a third spacing is provided between the fifth pin 5 and the sixth pin 6. The third spacing is smaller than the second spacing and the third spacing is smaller than the first spacing. The housing 100 includes multiple terminals. The substrate, the first pin 1, the second pin 2, the third pin 33, the fourth pin 44, the fifth pin 5 and the sixth pin 6 are encapsulated in the housing 100. The first pin 1, the second pin 2, the third pin 33, the fourth pin 44, the fifth pin 5 and the sixth pin 6 correspond one-to-one with the multiple terminals. The first pin 1, the second pin 2, the third pin 33, the fourth pin 44, the fifth pin 5 and the sixth pin 6 are all located in the corresponding terminals.

[0031] The beneficial effects of the coupler OP1 in this embodiment are as follows: the substrate facilitates the carrying of circuits; the first pin 1, the second pin 2, the third pin 33, and the fourth pin 44 facilitate the connection between the coupler OP1 and other devices, such as feedback modules and control modules; the fifth pin 5 and the sixth pin 6 facilitate the coupler OP1 to perform electrostatic discharge operation on the applied circuit, thereby discharging static electricity to ground, thus protecting the coupler OP1 and the devices connected to the primary and secondary ends of the coupler OP1 and avoiding unnecessary risks; the third spacing is set to be smaller than the first and second spacings, making the third spacing the shortest spacing, thereby ensuring that electrostatic discharge operation is preferentially performed through the fifth pin 5 and the sixth pin 6 during electrostatic discharge, thereby protecting the other devices and extending the service life of the circuit; the housing 100 protects the substrate and auxiliary pins to a certain extent, preventing impurities from covering the fifth pin 5 and the sixth pin 6, thus affecting the discharge effect.

[0032] For example, in some embodiments, reference is made to Figure 1 and Figure 2 In this embodiment, the coupler OP1 is an optocoupler OP1. The coupler OP1 also includes a light-emitting diode (LED) and a phototransistor. Both the LED and the phototransistor are disposed on the substrate. The coupler OP1 has six pins. The first pin 1 and the third pin 3 serve as the two ends for connecting the LED on the substrate to other components. The second pin 2 and the fourth pin 4 serve as the two ends for connecting the phototransistor on the substrate to other components. The electrical signal is converted into an optical signal by the LED and transmitted within the coupler OP1, causing the optical signal to be transmitted from the LED to the phototransistor. The optical signal is then converted into an electrical signal by the phototransistor and transmitted to other components through the second pin 2 and the fourth pin 4. This achieves isolation between the components at both ends of the coupler OP1 and ensures signal transmission. Pins 5 and 6 are used for electrostatic discharge (ESD) protection when coupler OP1 is applied in the circuit. The third spacing is smaller than the second spacing and also smaller than the first spacing, meaning the third spacing is the minimum. This ensures that when ESD occurs, the generated static electricity will first discharge through pins 5 and 6, preventing it from discharging through other pins and causing abnormal discharge that could damage other components and increase production costs. The housing 100 has multiple terminals 101, each terminal 101 corresponding to one pin. The terminal 101 is encapsulated with glass tubes, plastic tubes, or ceramic tubes, etc., to prevent the discharge tip from being blocked by plastic material when the terminal 101 is encapsulated together. It also prevents the discharge tip from being oxidized by air, which would lead to ESD discharge failure or performance degradation. The fifth pin 5 and the sixth pin 6 are located inside the corresponding terminal 101 to prevent foreign objects from covering the fifth pin 5 and the sixth pin 6 during the production process. This would prevent the fifth pin 5 and the sixth pin 6 from discharging the generated static electricity to the ground in time, causing damage to the circuit. The housing 100 makes the circuit used by the coupler OP1 more stable and safer.

[0033] It should be noted that: the first gap refers to the electrical clearance between the first pin 1 and the second pin 2, the second gap refers to the electrical clearance between the third pin 3 and the fourth pin 4, and the third gap refers to the electrical clearance between the fifth pin 5 and the sixth pin 6.

[0034] It should be noted that the coupler OP1 can also be an electromagnetic coupler or a capacitive coupler.

[0035] It is understandable that the first spacing is equal to the second spacing.

[0036] For example, in some embodiments, reference is made to Figure 1In this embodiment, the first spacing and the second spacing are set to be equal, which makes it easier to unify the actual length difference between the third spacing and the second spacing or the first spacing, and thus facilitates the adjustment of the third spacing to find the optimal actual difference between the third spacing and the second spacing or the first spacing, further ensuring the effect of the coupler OP1 of this application on electrostatic discharge.

[0037] It is understandable that the third spacing is 1.5mm shorter than the second spacing.

[0038] For example, in some embodiments, referring to the figure, in this embodiment, the third spacing is 1.5mm shorter than the second spacing, while the second spacing is equal to the first spacing, that is, the third spacing is also 1.5mm shorter than the first spacing. This is to ensure that the fifth pin 5 and the sixth pin 6 under the third spacing can achieve the best discharge effect. If the difference between the third spacing and the second spacing is less than 1.5mm, the generated static electricity may still not be discharged through the fifth pin 5 and the sixth pin 6, and will instead be discharged through other pins, which will affect the components connected to the primary and secondary ends of the coupler OP1, causing unnecessary damage and increasing the production cost of the product.

[0039] The switching power supply circuit according to the second aspect of the application includes the coupler OP1 of the first aspect of the application described above.

[0040] According to the switching power supply circuit of this application embodiment, the substrate is designed to facilitate the carrying capacity of the circuit. By setting the first pin 1, the second pin 2, the third pin 33, and the fourth pin 44, the coupler OP1 can easily establish a connection with other devices, such as the feedback module and the control module. The fifth pin 5 and the sixth pin 6 facilitate the coupler OP1 to perform electrostatic discharge operation on the applied circuit, thereby discharging the static electricity to the ground. This protects the coupler OP1 and the devices connected to the primary and secondary terminals of the coupler OP1, avoiding unnecessary risks. The third spacing is set to be smaller than the first and second spacings, making the third spacing the shortest spacing. This ensures that electrostatic discharge is preferentially performed through the fifth pin 5 and the sixth pin 6, thereby protecting the other devices and extending the service life of the circuit. The housing 100 protects the substrate and auxiliary pins to a certain extent, and also prevents impurities from covering the fifth pin 5 and the sixth pin 6, thus affecting the discharge effect. By introducing the coupler OP1 of this application, the switching power supply circuit of this application has higher stability and better ensures the user experience.

[0041] It is understood that the switching power supply in this embodiment of the application further includes a control module and a feedback module. One end of the control module is used to connect to a power source, and the other end is connected to one end of a transformer. The transformer is used to boost or step down the voltage output by the control module. The input end of the feedback module is connected to the other end of the transformer, and the output end of the feedback module is connected to the control module through a coupler OP1. The fifth pin 5 is connected to the input end of the feedback module, and the sixth pin 6 is grounded. The fifth pin 5 and the sixth pin 6 are used to discharge the static electricity generated by the switching power supply circuit to the ground.

[0042] For example, in some embodiments, reference is made to Figure 3 In this embodiment, transformer T1 boosts or bucks the voltage output by the control module, and then outputs the output voltage of the switching power supply circuit through V+ and V- terminals. The first input terminal of the feedback module is connected to the V+ terminal, and the second input terminal of the feedback module is connected to the V- terminal, so that the feedback module can obtain the output voltage of the switching power supply circuit. The feedback module then compares the output voltage of the switching power supply circuit with a preset reference voltage. If the output voltage of the switching power supply circuit is greater than the reference voltage, a first feedback signal is output. The first feedback signal is transmitted to the control module through coupler OP1, thereby reducing the output voltage of the control module. If the output voltage of the switching power supply circuit is less than the reference voltage, a second feedback signal is output. The second feedback signal is transmitted to the control module through coupler OP1, thereby increasing the output voltage of the control module. Thus, the output voltage of the switching power supply circuit is regulated. The fifth pin 5 is connected to the V- terminal, and the sixth pin 6 is grounded to GND, so that the fifth pin 5 and the sixth pin 6 form a loop with the switching power supply circuit, causing the static energy generated at the V+ or V- terminal to be discharged to the ground through the fifth pin 5 and the sixth pin 6, thereby protecting the feedback module and the control module.

[0043] It is understood that the switching power supply circuit in this application embodiment also includes a rectifier bridge BD1. The control module is connected to the power supply through the rectifier bridge BD1. The rectifier bridge BD1 is used to convert the input AC power into DC power and output it to the control module.

[0044] For example, in some embodiments, reference is made to Figure 3 In this embodiment, the first input terminal of rectifier bridge BD1 is connected to the live wire L of the power grid, the second input terminal of rectifier bridge BD1 is connected to the neutral wire N of the power grid, the negative terminal of rectifier bridge BD1 is grounded, and the positive terminal of rectifier bridge BD1 is connected to the control module. The power grid serves as the power source to provide AC power to the switching power supply circuit. Rectifier bridge BD1 is located between the power grid and the control module to facilitate the conversion of AC power input from the power grid into DC power output to the control module.

[0045] It is understood that the switching power supply circuit in this application embodiment also includes a filter, one end of which is connected to the output terminal of the rectifier bridge BD1, and the other end of which is connected to the input terminal of the control module.

[0046] For example, in some embodiments, reference is made to Figure 3 In this embodiment, the filter consists of L1, R1, CE1, and CE2, and is a π-type filter. The positive output terminal of the rectifier bridge BD1 is connected to the control module through the π-type filter so as to filter out the high-frequency noise generated by the switching power supply, thereby protecting the control module, reducing EMC electromagnetic interference, and extending the service life of the control module.

[0047] It is understood that the switching power supply circuit in this application embodiment also includes a fuse F1, and the first output terminal of the power supply is connected to the first input terminal of the rectifier bridge BD1 through the fuse F1.

[0048] For example, in some embodiments, reference is made to Figure 3 In this embodiment, the first output terminal of the power supply, i.e. the live wire L of the power grid, is connected to the first input terminal of the rectifier bridge BD1 through the fuse F1. This allows the fuse F1 to blow due to excessive current when an overcurrent occurs in the switching power supply circuit, such as a short circuit or a surge current. This prevents the current from being transmitted and protects subsequent components such as the rectifier bridge BD1, the π-type filter, the control module, and the feedback module, thereby reducing the replacement cost of the switching power supply circuit in the event of an overcurrent.

[0049] It is understood that the switching power supply circuit of this application embodiment also includes a thermistor NTC1, and the second output terminal of the power supply is connected to the second input terminal of the rectifier bridge BD1 through the thermistor.

[0050] For example, in some embodiments, reference is made to Figure 3 In this embodiment, the second output terminal of the power supply, i.e. the neutral line N of the power grid, is connected to the second input terminal of the rectifier bridge BD1 through the thermistor NTC1. The thermistor NTC1 has a large resistance at room temperature, which helps to suppress the surge current generated when the switching power supply circuit starts up. This further protects subsequent components such as the rectifier bridge BD1, the π-type filter, the control module, and the feedback module, reducing the frequency of damage to components in the switching power supply circuit and thus reducing production costs.

[0051] It is understandable that the control module includes a pulse width modulation control unit and a field-effect transistor control unit. One end of the pulse width modulation control unit is used to connect to the power supply, and the other end of the pulse width modulation control unit is connected to one end of the field-effect transistor control unit. The other end of the field-effect transistor control unit is connected to the transformer.

[0052] For example, in some embodiments, the control module includes a pulse width modulation (PWM) control unit and a field-effect transistor (FET) control unit. The FET control unit includes a FET, and the PWM control unit is used to adjust the on and off times of the FET. The FET control unit performs on or off operations on the FET based on the signal output by the PWM control unit. For example, if the PWM control unit outputs a high level, the FET control unit controls the FET to turn on; if the PWM control unit outputs a low level, the FET control unit controls the FET to turn off. This achieves control and regulation of the voltage output by the control module.

[0053] For example, in some embodiments, reference is made to Figure 3 In this embodiment, the specific path of electrostatic discharge generated by the switching power supply circuit is as follows: static electricity enters the switching power supply circuit from the V+ and V- terminals. Since the third gap between the fifth pin 5 and the sixth pin 6 is the shortest, the static current flows through the fifth pin 5 and the sixth pin 6, through GND or the L1 of the π-type filter to the rectifier bridge BD1, and then through the thermistor NTC1 or the fuse F1 into the power grid, and finally discharged to the ground. It can be seen that the path of static electricity does not pass through the control module and the feedback module, and therefore will not damage the control module and the feedback module, thus achieving the purpose and effect of protection.

[0054] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A coupler, characterized in that, include: substrate; The auxiliary pins include a first pin, a second pin, a third pin, a fourth pin, a fifth pin, and a sixth pin. The first pin and the second pin are mirror images of each other on opposite sides of the substrate along the central axis of the substrate. The third pin and the fourth pin are mirror images of each other on opposite sides of the substrate along the central axis of the substrate. The fifth pin and the sixth pin are mirror images of each other on opposite sides of the substrate along the central axis of the substrate. The first pin, the third pin, and the fifth pin are located on the same side of the substrate. A first spacing is provided between the first pin and the second pin. A second spacing is provided between the third pin and the fourth pin. A third spacing is provided between the fifth pin and the sixth pin. The third spacing is smaller than the second spacing and the third spacing is smaller than the first spacing. The housing includes multiple terminals. The substrate, the first pin, the second pin, the third pin, the fourth pin, the fifth pin, and the sixth pin are encapsulated within the housing. The first pin, the second pin, the third pin, the fourth pin, the fifth pin, and the sixth pin correspond one-to-one with the multiple terminals. The first pin, the second pin, the third pin, the fourth pin, the fifth pin, and the sixth pin are all disposed within the corresponding terminals.

2. The coupler according to claim 1, characterized in that, The first spacing is equal to the second spacing.

3. The coupler according to claim 2, characterized in that, The third spacing is 1.5 mm shorter than the second spacing.

4. A switching power supply circuit, characterized in that, include: The coupler according to any one of claims 1 to 3.

5. The switching power supply circuit according to claim 4, characterized in that, It also includes a control module and a feedback module. One end of the control module is connected to a power source, and the other end is connected to one end of a transformer. The transformer is used to boost or buck the voltage output by the control module. The input end of the feedback module is connected to the other end of the transformer, and the output end of the feedback module is connected to the control module through the coupler. The fifth pin is connected to the input end of the feedback module, and the sixth pin is grounded. The fifth and sixth pins are used to discharge the static electricity generated by the switching power supply circuit to the ground.

6. The switching power supply circuit according to claim 5, characterized in that, It also includes a rectifier bridge, through which the control module is connected to the power supply. The rectifier bridge is used to convert the input AC power into DC power and output it to the control module.

7. The switching power supply circuit according to claim 6, characterized in that, It also includes a filter, one end of which is connected to the output of the rectifier bridge, and the other end of which is connected to the input of the control module.

8. The switching power supply circuit according to claim 6, characterized in that, It also includes a fuse, and the first output terminal of the power supply is connected to the first input terminal of the rectifier bridge through the fuse.

9. The switching power supply circuit according to claim 6, characterized in that, It also includes a thermistor, and the second output terminal of the power supply is connected to the second input terminal of the rectifier bridge through the thermistor.

10. The switching power supply circuit according to claim 5, characterized in that, The control module includes a pulse width modulation control unit and a field-effect transistor control unit. One end of the pulse width modulation control unit is connected to the power supply, and the other end of the pulse width modulation control unit is connected to one end of the field-effect transistor control unit. The other end of the field-effect transistor control unit is connected to the transformer.

Images