Switching power supply compatible with different external detections

Abstract

The utility model relates to the technical field of switching power supplies, in particular to a switching power supply compatible with different external detections, which comprises a main loop and a microcontroller, and is characterized by also comprising an external voltage conversion module, an external detection access module and an external detection feedback module, the output end of the main loop is electrically connected with an external voltage conversion module and an external detection access module in sequence, the external detection access module is externally connected with an external sensor, and the external detection access module is electrically connected with the microcontroller through an external detection feedback module; the external voltage conversion module is used for isolation and is also used for carrying out voltage conversion on the output voltage of the main loop and then supplying power to the external detection access module; the external detection access module is used for receiving different types of detection signals from an external sensor, generating feedback signals of the same type, and transmitting the feedback signals to the microcontroller through the external detection feedback module; the problem that the switching power supply cannot be compatible with different external detections is solved.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, and in particular to a switching power supply that is compatible with different external detection methods. Background Technology

[0002] With the advancement of technology and the development of electronic devices, the performance and functional requirements of switching power supplies are constantly increasing. Especially in certain specific application scenarios, such as those requiring fault early warning or external environment monitoring, traditional switching power supplies need to be designed with specific detection circuits or selected with appropriate integrated detection modules connected to a microcontroller (such as an MCU) to meet the requirements.

[0003] However, whether designing a specific detection circuit or selecting to connect to the corresponding integrated detection module, each has its own voltage conversion (matching voltage) and signal conversion (converting the PWM, resistance, or level signals fed back by the sensor into signals that the microcontroller can recognize). Often, one detection circuit or module can only correspond to one type of external detection. When the detection requirements change, the detection circuit or module needs to be changed, which is costly and makes the switching power supply incompatible with different external detections. Utility Model Content

[0004] To address the aforementioned shortcomings, the purpose of this invention is to propose a switching power supply that is compatible with different external sensors, thus solving the problem that switching power supplies cannot be compatible with different external sensors.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A switching power supply compatible with different external detections includes a main circuit and a microcontroller, and further includes an external voltage conversion module, an external detection access module, and an external detection feedback module; the output terminal of the main circuit is electrically connected to the external voltage conversion module and the external detection access module in sequence, the external detection access module is connected to an external sensor, and the external detection access module is electrically connected to the microcontroller through the external detection feedback module;

[0007] The external voltage conversion module is used for isolation and also for converting the output voltage of the main circuit to power the external detection access module.

[0008] The external detection access module is used to receive different types of detection signals from the external sensor, generate the same type of feedback signal, and transmit the feedback signal to the microcontroller through the external detection feedback module.

[0009] Furthermore, it also includes an internal voltage conversion module and a switching module; the output terminal of the main circuit is also electrically connected to the input terminal of the internal voltage conversion module, and the first output terminal and the second output terminal of the internal voltage conversion module are respectively electrically connected to the SGND ground terminal circuit and the GND ground terminal circuit of the main circuit.

[0010] The internal voltage conversion module is used for isolation and also for converting the output voltage of the main circuit to generate a first conversion voltage and a second conversion voltage. The first conversion voltage and the second conversion voltage supply power to the SGND ground circuit and the GND ground circuit of the main circuit, respectively.

[0011] The second output terminal of the internal voltage conversion module is also electrically connected to the input terminal of the switching module. The output terminal of the switching module is electrically connected to the flyback drive module and the PFC module of the main circuit, respectively. The control terminal of the switching module is electrically connected to the microcontroller.

[0012] The microcontroller controls the second conversion voltage to power the flyback drive module and PFC module of the main circuit through the switching module.

[0013] Furthermore, the external detection access module includes multiple signal conversion chips U15 and a signal preprocessing circuit; the VCC and VIN terminals of the multiple signal conversion chips U15 are both electrically connected to the external voltage conversion module; the external sensor is electrically connected to the input terminal of the multiple signal conversion chips U15 via the signal preprocessing circuit; and the output terminal of the multiple signal conversion chips U15 is electrically connected to the microcontroller via the external detection feedback module.

[0014] The multi-signal conversion chip U15 is used to receive different types of detection signals from the external sensor through the signal preprocessing circuit, generate the same type of feedback signal, and transmit the feedback signal to the microcontroller through the external detection feedback module.

[0015] Furthermore, the preprocessing circuit includes capacitors C55 and C56, resistor R108, bidirectional TVS diode TVS1, inductor L9, and inductor L10. One end of resistor R108 is electrically connected to the input terminal of the multi-signal conversion chip U15, and one end of resistor R108 is also electrically connected to one end of capacitor C56. The other end of resistor R108 and one end of bidirectional TVS diode TVS1 are both electrically connected to one end of inductor L9. The other end of inductor L9 is electrically connected to one end of capacitor C55. The other ends of capacitor C56, the other end of bidirectional TVS diode TVS1, and one end of inductor L10 are all connected to SGND (ground terminal). The other end of inductor L10 is electrically connected to the other end of capacitor C55. One end and the other end of capacitor C55 are both electrically connected to the external sensor.

[0016] Furthermore, the external voltage conversion module includes capacitor C49, transformer T3, capacitor C52, resistor R100, diode D20, capacitor CE6, resistor R102, capacitor C53, and capacitor C54; the opposite-named terminal of the primary side of transformer T3 is electrically connected to the output terminal of the main circuit, the same-named terminal of the primary side of transformer T3 is connected to GND ground, and capacitor C49 is connected in parallel between the same-named terminal and the opposite-named terminal of the primary side of transformer T3;

[0017] The same-name terminal on the secondary side of transformer T3 and one end of capacitor C52 are electrically connected to the anode of diode D20. The other end of capacitor C52 is electrically connected to one end of resistor R100. The other end of resistor R100, the cathode of diode D20, the positive terminal of capacitor CE6, and one end of resistor R102 are all electrically connected to one end of capacitor C53. The opposite-name terminal on the secondary side of transformer T3, the negative terminal of capacitor CE6, the other end of resistor R102, the other end of capacitor C53, and one end of capacitor C54 are all connected to SGND ground. The other ends of capacitor C53 and capacitor C54 are both electrically connected to the external detection access module.

[0018] Furthermore, the external detection feedback module includes resistor R121, capacitor C64, resistor R125, optocoupler U21, resistor R126, capacitor C65, and resistor R124; the anode of the light source of the optocoupler U21 is electrically connected to the external detection access module via resistor R121, the cathode of the light source of the optocoupler U21 is connected to the SGND ground terminal, and resistor R125 and capacitor C64 are connected in parallel between the anode and cathode of the light source of the optocoupler U21;

[0019] The collector of the photodetector U21 is connected to a 3V3 power supply. The emitter of the photodetector U21 is electrically connected to the microcontroller via the resistor R124. The emitter of the photodetector U21 is connected to the GND ground terminal. The resistor R126 and the capacitor C65 are connected in parallel between the emitter of the photodetector U21 and the GND ground terminal.

[0020] Furthermore, the internal voltage conversion module includes a voltage regulator chip U10, an AC / DC constant voltage chip U11, capacitors C38, CE1, C40, CE2, C44, CE4, C39, C36, C41, resistor R77, diode D14, transformer T2, resistors R86 and R87, diodes D15 and D16, and a Zener diode DZ2; the drain terminal of the power transistor of the AC / DC constant voltage chip U11 is used as the input terminal of the internal voltage conversion module, the output terminal of the voltage regulator chip U10 is used as the first output terminal of the internal voltage conversion module, and the non-polarized terminal on the primary side of the transformer T2 is used as the second output terminal of the internal voltage conversion module.

[0021] One end of capacitor C36 and one end of capacitor C41 are both electrically connected to the drain terminal of the power transistor of AC / DC constant voltage chip U11. The other end of capacitor C41 is connected to GND. The other end of capacitor C36, the anode of diode D15, the positive terminal of capacitor CE4, one end of capacitor C44, and one end of resistor R86 are all electrically connected to the opposite-name terminal of the primary side of transformer T2. The cathode of diode D15 is electrically connected to the cathode of Zener diode DZ2. One end of capacitor C39, the VCC terminal of AC / DC constant voltage chip U11, and the A The voltage selection terminal of the AC / DC constant voltage chip U11 is electrically connected to the anode of the Zener diode DZ2. The GND terminal of the AC / DC constant voltage chip U11, the other end of the capacitor C39, and the cathode of the diode D16 are all electrically connected to the same terminal on the primary side of the transformer T2. The current sampling terminal of the AC / DC constant voltage chip U11 is electrically connected to the GND terminal of the AC / DC constant voltage chip U11 through the resistor R87. The anode of the diode D16, the cathode of the capacitor CE4, the other end of the capacitor C44, and the other end of the resistor R86 are all connected to the GND ground terminal.

[0022] The same-name terminal of the secondary side of the transformer T2 is electrically connected to the anode of the diode D14. The cathode of the diode D14 is electrically connected to the input terminal of the voltage regulator chip U10 through the resistor R77. The GND terminal of the voltage regulator chip U10 is connected to the SGND ground terminal. The capacitor C40 and the capacitor CE2 are connected in parallel between the input terminal and the SGND ground terminal of the voltage regulator chip U10. The capacitor C38 and the capacitor CE1 are connected in parallel between the output terminal and the SGND ground terminal of the voltage regulator chip U10.

[0023] Furthermore, the switching module includes resistors R78, R80, R76, and R45, capacitor C37, transistor Q7, and MOSFET Q4; one end of resistor R78 is used as the control terminal of the switching module, the drain of MOSFET Q4 is used as the input terminal of the switching module, and the source of MOSFET Q4 is used as the output terminal of the switching module.

[0024] The other end of resistor R78 is electrically connected to the base of transistor Q7. The collector of transistor Q7 is electrically connected to the gate of MOSFET Q4. The emitter of transistor Q7 is connected to GND. Resistor R80 and capacitor C37 are connected in parallel between the base of transistor Q7 and GND. Resistor R76 is connected in parallel between the collector of transistor Q7 and GND. Resistor R45 is connected in parallel between the gate and drain of MOSFET Q4.

[0025] The technical solution provided by this utility model can include the following beneficial effects: An external detection circuit, consisting of an external voltage conversion module, an external detection access module, and an external detection feedback module, is added to the switching power supply. The external voltage conversion module converts the output voltage of the main circuit and supplies power to the external detection access module separately, while also providing power supply isolation. This reduces the impact of the external detection circuit on other circuits within the switching power supply, allowing the external detection access module to operate independently. When an external sensor (such as a thermistor, infrared temperature sensor, etc.) is connected, different types of detection signals are received from the external sensor, generating the same type of feedback signal, which is then transmitted to the microcontroller via the external detection feedback module. Thus, only one external detection circuit is needed to uniformly convert the detection signals from different external sensors (such as level, PWM, resistance, etc.) into the same feedback signal (such as one of level, PWM, resistance, etc.) for the microcontroller to recognize. This approach is low-cost and compatible with different external detection methods. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a switching power supply compatible with different external detectors, which is one embodiment of this utility model.

[0027] Figure 2Is it like this? Figure 1 The circuit diagram shown is for the external voltage conversion module, the external detection access module, and the external detection feedback module.

[0028] Figure 3 Is it like this? Figure 1 The circuit diagram of the internal voltage conversion module is shown.

[0029] Figure 4 Is it like this? Figure 1 The circuit diagram of the switch module shown is shown.

[0030] The circuit consists of: main circuit 1, external voltage conversion module 2, external detection access module 3, external detection feedback module 4, microcontroller 5, internal voltage conversion module 6, switch module 7, multi-signal conversion chip U15, signal preprocessing circuit 31, capacitor C55, capacitor C56, resistor R108, bidirectional TVS diode TVS1, inductor L9, inductor L10, capacitor C49, transformer T3, capacitor C52, resistor R100, diode D20, capacitor CE6, resistor R102, capacitor C53, capacitor C54, resistor R121, capacitor C64, and resistor R125. Optocoupler U21, Resistor R126, Capacitor C65, Resistor R124, Voltage Regulator Chip U10, AC / DC Constant Voltage Chip U11, Capacitor C38, Capacitor CE1, Capacitor C40, Capacitor CE2, Capacitor C44, Capacitor CE4, Capacitor C39, Capacitor C36, Capacitor C41, Resistor R77, Diode D14, Transformer T2, Resistor R86, Resistor R87, Diode D15, Diode D16, Zener Diode DZ2, Resistor R78, Resistor R80, Resistor R76, Resistor R45, Capacitor C37, Transistor Q7, MOSFET Q4. Detailed Implementation

[0031] The embodiments of this utility model 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 utility model, and should not be construed as limiting this utility model.

[0032] In the description of embodiments of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0034] The following is combined Figures 1 to 4 This invention describes a switching power supply compatible with different external detectors according to an embodiment of the present invention.

[0035] A switching power supply compatible with different external detections includes a main circuit 1 and a microcontroller 5, and also includes an external voltage conversion module 2, an external detection access module 3 and an external detection feedback module 4; the output terminal of the main circuit 1 is electrically connected to the external voltage conversion module 2 and the external detection access module 3 in sequence, the external detection access module 3 is connected to an external sensor, and the external detection access module 3 is electrically connected to the microcontroller 5 through the external detection feedback module 4.

[0036] The external voltage conversion module 2 is used for isolation and also for converting the output voltage of the main circuit 1 to power the external detection access module 3.

[0037] The external detection access module 3 is used to receive different types of detection signals from external sensors, generate the same type of feedback signal, and transmit the feedback signal to the microcontroller 5 through the external detection feedback module 4.

[0038] This utility model proposes a preferred embodiment of a switching power supply that is compatible with different external detection methods, such as... Figure 1 As shown, an external detection circuit consisting of an external voltage conversion module 2, an external detection access module 3, and an external detection feedback module 4 is added to the switching power supply. The external voltage conversion module 2 converts the output voltage of the main circuit 1 and supplies power to the external detection access module 3 separately, while also providing power supply isolation to reduce the impact of the external detection circuit on other circuits inside the switching power supply, allowing the external detection access module 3 to work independently. When an external sensor (such as a thermistor, infrared temperature sensor, etc.) is connected, different types of detection signals are received from the external sensor, generating the same type of feedback signal, which is transmitted to the microcontroller 5 via the external detection feedback module 4. Thus, only one external detection circuit is needed to uniformly convert the detection signals (such as level, PWM, resistance, etc.) of different external sensors into the same feedback signal (such as one of the level, PWM, resistance, etc.) for the microcontroller 5 to recognize. This is low-cost and compatible with different external detections.

[0039] It should be noted that when multiple sensors need to be set for external detection, multiple external detection circuits can be added to increase the number of access points for the external sensors.

[0040] Furthermore, it also includes an internal voltage conversion module 6 and a switching module 7; the output terminal of the main circuit 1 is also electrically connected to the input terminal of the internal voltage conversion module 6, and the first output terminal and the second output terminal of the internal voltage conversion module 6 are respectively electrically connected to the SGND ground terminal circuit and the GND ground terminal circuit of the main circuit 1.

[0041] The internal voltage conversion module 6 is used for isolation and also for converting the output voltage of the main circuit 1 to generate a first conversion voltage and a second conversion voltage. The first conversion voltage and the second conversion voltage supply power to the SGND ground circuit and the GND ground circuit of the main circuit 1, respectively.

[0042] The second output terminal of the internal voltage conversion module 6 is also electrically connected to the input terminal of the switch module 7. The output terminal of the switch module 7 is electrically connected to the flyback drive module and the PFC module of the main circuit 1, respectively. The control terminal of the switch module 7 is electrically connected to the microcontroller 5.

[0043] The microcontroller 5 controls the second conversion voltage to power the flyback drive module and PFC module of the main circuit 1 through the switching module 7.

[0044] In this embodiment, after adding an external detection circuit, the switching power supply may experience excessive power consumption as it also needs to power the external detection circuit. Therefore, it is necessary to plan and control the power supply to other internal circuits of the switching power supply to ensure that some modules are shut down during low-brightness dimming phases to reduce power consumption. Thus, the internal voltage conversion module 6 converts the output voltage of the main circuit 1, generating a first conversion voltage (BL3.3V) and a second conversion voltage (18V), which power the SGND ground terminal circuit and the GND ground terminal circuit of the main circuit 1, respectively. This separates the power supply to circuits with different grounding terminals, reducing power consumption. To reduce interference, further voltage conversion can be performed based on the power supply requirements of different circuits in the SGND and GND ground circuits (for example, in the GND ground circuit, in addition to converting to 18V to power the flyback drive module and PFC module, it is also necessary to power the microcontroller 5, so a voltage regulator chip and its peripheral circuits need to be added to convert 18V to 3.3V to power the microcontroller 5); at the same time, since the flyback drive module and PFC module in the main circuit 1 can be turned off in different situations to reduce power consumption, a switch module 7 is added to control the power supply of the flyback drive module and PFC module by the microcontroller 5, realizing the switching control of the module.

[0045] Furthermore, the external detection access module 3 includes multiple signal conversion chips U15 and a signal preprocessing circuit 31; the VCC and VIN terminals of the multiple signal conversion chips U15 are electrically connected to the external voltage conversion module 2, the external sensor is electrically connected to the input terminal of the multiple signal conversion chips U15 via the signal preprocessing circuit 31, and the output terminal of the multiple signal conversion chips U15 is electrically connected to the microcontroller 5 via the external detection feedback module 4.

[0046] The multi-signal conversion chip U15 is used to receive different types of detection signals from external sensors through the signal preprocessing circuit 31, generate the same type of feedback signal, and transmit the feedback signal to the microcontroller 5 through the external detection feedback module 4.

[0047] In this embodiment, as Figure 2 As shown, various signal conversion chips U15, such as the XP1101 model chip (where the DIM terminal is the input terminal and the DRV terminal is the output terminal), support the conversion of level, resistance, and PWM signals into PWM signals for microcontroller 5 to recognize. Therefore, the external detection access module 3 is preferably composed of such various signal conversion chips U15 and signal preprocessing circuit 31. The signal preprocessing circuit 31 mainly preprocesses the detection signals from external sensors to obtain stable detection signals.

[0048] Furthermore, the preprocessing circuit 31 includes capacitors C55 and C56, resistor R108, bidirectional TVS diode TVS1, inductor L9, and inductor L10. One end of resistor R108 is electrically connected to the input terminal of the multi-signal conversion chip U15, and one end of resistor R108 is also electrically connected to one end of capacitor C56. The other end of resistor R108 and one end of bidirectional TVS diode TVS1 are both electrically connected to one end of inductor L9. The other end of inductor L9 is electrically connected to one end of capacitor C55. The other end of capacitor C56, the other end of bidirectional TVS diode TVS1, and one end of inductor L10 are all connected to the SGND ground terminal. The other end of inductor L10 is electrically connected to the other end of capacitor C55. One end and the other end of capacitor C55 are both electrically connected to an external sensor.

[0049] In this embodiment, the preprocessing circuit 31 is preferably composed of capacitor C55, capacitor C56, resistor R108, bidirectional TVS diode TVS1, inductor L9 and inductor L10, which can perform impedance matching and shaping filtering on the detection signal transmitted by thermistor (NTC) to obtain a stable detection signal.

[0050] Furthermore, the external voltage conversion module 2 includes capacitor C49, transformer T3, capacitor C52, resistor R100, diode D20, capacitor CE6, resistor R102, capacitor C53, and capacitor C54; the opposite-name terminal of the primary side of transformer T3 is electrically connected to the output terminal of the main circuit 1, the same-name terminal of the primary side of transformer T3 is connected to GND ground, and capacitor C49 is connected in parallel between the same-name terminal and the opposite-name terminal of the primary side of transformer T3;

[0051] The same-name terminal of the secondary side of transformer T3 and one end of capacitor C52 are electrically connected to the anode of diode D20. The other end of capacitor C52 is electrically connected to one end of resistor R100. The other end of resistor R100, the cathode of diode D20, the positive terminal of capacitor CE6, and one end of resistor R102 are all electrically connected to one end of capacitor C53. The opposite-name terminal of the secondary side of transformer T3, the negative terminal of capacitor CE6, the other end of resistor R102, the other end of capacitor C53, and one end of capacitor C54 are all connected to the SGND ground terminal. The other ends of capacitor C53 and capacitor C54 are both electrically connected to the external detection access module 3.

[0052] In this embodiment, the external voltage conversion module 2 is to achieve both isolation and voltage conversion. Preferably, the voltage conversion circuit is composed of a transformer T3 and its peripheral circuits. The transformer T3 can play an isolation role, and the primary and secondary circuits of the transformer T3 can play a shaping and filtering role.

[0053] Furthermore, the external detection feedback module 4 includes resistor R121, capacitor C64, resistor R125, optocoupler U21, resistor R126, capacitor C65, and resistor R124; the anode of the light source of optocoupler U21 is electrically connected to the external detection access module 3 via resistor R121, the cathode of the light source of optocoupler U21 is connected to the SGND ground terminal, and resistor R125 and capacitor C64 are connected in parallel between the anode and cathode of the light source of optocoupler U21;

[0054] The collector of the photodetector U21 is connected to a 3V3 power supply. The emitter of the photodetector U21 is electrically connected to the microcontroller 5 via resistor R124. The emitter of the photodetector U21 is connected to the GND ground terminal. A resistor R126 and a capacitor C65 are connected in parallel between the emitter of the photodetector U21 and the GND ground terminal.

[0055] In this embodiment, since the signal conversion chip U15 is connected to the SGND ground terminal, which is different from the ground terminal of the microcontroller 5, isolated transmission is required. Therefore, the external detection feedback module 4 is composed of the optocoupler U21 and its peripheral circuit.

[0056] Furthermore, the internal voltage conversion module 6 includes a voltage regulator chip U10, an AC / DC constant voltage chip U11, capacitors C38, CE1, C40, CE2, C44, CE4, C39, C36, and C41, a resistor R77, a diode D14, a transformer T2, resistors R86 and R87, diodes D15 and D16, and a Zener diode DZ2; the drain terminal of the power transistor of the AC / DC constant voltage chip U11 is used as the input terminal of the internal voltage conversion module 6, the output terminal of the voltage regulator chip U10 is used as the first output terminal of the internal voltage conversion module 6, and the non-polarized terminal of the primary side of the transformer T2 is used as the second output terminal of the internal voltage conversion module 6;

[0057] One end of capacitor C36 and one end of capacitor C41 are both electrically connected to the drain terminal of the power transistor in AC / DC constant voltage chip U11. The other end of capacitor C41 is connected to GND. The other end of capacitor C36, the anode of diode D15, the positive terminal of capacitor CE4, one end of capacitor C44, and one end of resistor R86 are all electrically connected to the opposite-name terminal of the primary side of transformer T2. The cathode of diode D15 is electrically connected to the cathode of Zener diode DZ2. One end of capacitor C39, the VCC terminal of AC / DC constant voltage chip U11, and AC / DC... The voltage selection terminal of the AC / DC constant voltage chip U11 is electrically connected to the anode of the Zener diode DZ2. The GND terminal of the AC / DC constant voltage chip U11, the other end of the capacitor C39, and the cathode of the diode D16 are all electrically connected to the same-name terminal on the primary side of the transformer T2. The current sampling terminal of the AC / DC constant voltage chip U11 is electrically connected to the GND terminal of the AC / DC constant voltage chip U11 through the resistor R87. The anode of the diode D16, the cathode of the capacitor CE4, the other end of the capacitor C44, and the other end of the resistor R86 are all connected to the GND ground terminal.

[0058] The same-name terminal of the secondary side of transformer T2 is electrically connected to the anode of diode D14. The cathode of diode D14 is electrically connected to the input terminal of voltage regulator chip U10 through resistor R77. The GND terminal of voltage regulator chip U10 is connected to the SGND ground terminal. Capacitors C40 and CE2 are connected in parallel between the input terminal and the SGND ground terminal of voltage regulator chip U10. Capacitors C38 and CE1 are connected in parallel between the output terminal and the SGND ground terminal of voltage regulator chip U10.

[0059] In this embodiment, as Figure 3As shown, the internal voltage conversion module 6 consists of a transformer T2, a voltage regulator chip U10 (such as a 3.3V voltage regulator chip - AMS1117 chip) and its peripheral circuits, and an AC / DC constant voltage chip U11 (such as a BP2522X chip, where the D terminal is the drain terminal of the power transistor, the SEL terminal is the voltage selection terminal, and the CS terminal is the current sampling terminal) and its peripheral circuits. The transformer T2 provides isolation. The voltage conversion is performed by the voltage regulator chip U10 and its peripheral circuits, and by the AC / DC constant voltage chip U11 and its peripheral circuits, respectively, to meet the supply voltage requirements of the SGND and GND grounding circuits of the main circuit 1. If further voltage conversion is required, a voltage conversion circuit can be connected to the first or second output terminal of the internal voltage conversion module 6 to further reduce the voltage and meet the supply voltage requirements.

[0060] Furthermore, the switching module 7 includes resistors R78, R80, R76, and R45, capacitor C37, transistor Q7, and MOSFET Q4; one end of resistor R78 is used as the control terminal of the switching module 7, the drain of MOSFET Q4 is used as the input terminal of the switching module 7, and the source of MOSFET Q4 is used as the output terminal of the switching module 7.

[0061] The other end of resistor R78 is electrically connected to the base of transistor Q7. The collector of transistor Q7 is electrically connected to the gate of MOSFET Q4. The emitter of transistor Q7 is connected to GND. Resistor R80 and capacitor C37 are connected in parallel between the base of transistor Q7 and GND. Resistor R76 is connected in parallel between the collector of transistor Q7 and GND. Resistor R45 is connected in parallel between the gate and drain of MOSFET Q4.

[0062] In this embodiment, as Figure 4 As shown, the switching module 7 is connected to the second output terminal of the internal voltage conversion module 6 and the VCC terminal of the flyback drive module or PFC module in the main circuit 1 through the MOSFET Q4 to form a power supply circuit. Then, the microcontroller 5 controls the MOSFET Q4 through the transistor Q7 to realize the on and off control of the power supply circuit, so that the microcontroller 5 can control the switching of the flyback drive module and the PFC module.

[0063] Other configurations and operations of a switching power supply compatible with different external detections according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0064] In the description of this specification, references to terms such as "embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0065] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A switching power supply compatible with different external sensors, comprising a main circuit and a microcontroller, characterized in that: It also includes an external voltage conversion module, an external detection access module, and an external detection feedback module; the output terminal of the main circuit is electrically connected to the external voltage conversion module and the external detection access module in sequence, the external detection access module is connected to an external sensor, and the external detection access module is electrically connected to the microcontroller through the external detection feedback module; The external voltage conversion module is used for isolation and also for converting the output voltage of the main circuit to power the external detection access module. The external detection access module is used to receive different types of detection signals from the external sensor, generate the same type of feedback signal, and transmit the feedback signal to the microcontroller through the external detection feedback module.

2. The switching power supply compatible with different external detectors according to claim 1, characterized in that: It also includes an internal voltage conversion module and a switching module; the output terminal of the main circuit is also electrically connected to the input terminal of the internal voltage conversion module, and the first output terminal and the second output terminal of the internal voltage conversion module are respectively electrically connected to the SGND ground terminal circuit and the GND ground terminal circuit of the main circuit. The internal voltage conversion module is used for isolation and also for converting the output voltage of the main circuit to generate a first conversion voltage and a second conversion voltage. The first conversion voltage and the second conversion voltage supply power to the SGND ground circuit and the GND ground circuit of the main circuit, respectively. The second output terminal of the internal voltage conversion module is also electrically connected to the input terminal of the switching module. The output terminal of the switching module is electrically connected to the flyback drive module and the PFC module of the main circuit, respectively. The control terminal of the switching module is electrically connected to the microcontroller. The microcontroller controls the second conversion voltage to power the flyback drive module and PFC module of the main circuit through the switching module.

3. A switching power supply compatible with different external sensors according to claim 1, characterized in that: The external detection access module includes multiple signal conversion chips U15 and a signal preprocessing circuit; the VCC and VIN terminals of the multiple signal conversion chips U15 are both electrically connected to the external voltage conversion module; the external sensor is electrically connected to the input terminal of the multiple signal conversion chips U15 via the signal preprocessing circuit; and the output terminal of the multiple signal conversion chips U15 is electrically connected to the microcontroller via the external detection feedback module. The multi-signal conversion chip U15 is used to receive different types of detection signals from the external sensor through the signal preprocessing circuit, generate the same type of feedback signal, and transmit the feedback signal to the microcontroller through the external detection feedback module.

4. A switching power supply compatible with different external sensors according to claim 3, characterized in that: The preprocessing circuit includes capacitors C55 and C56, resistor R108, bidirectional TVS diode TVS1, inductor L9, and inductor L10. One end of resistor R108 is electrically connected to the input terminal of the multi-signal conversion chip U15. One end of resistor R108 is also electrically connected to one end of capacitor C56. The other end of resistor R108 and one end of bidirectional TVS diode TVS1 are both electrically connected to one end of inductor L9. The other end of inductor L9 is electrically connected to one end of capacitor C55. The other ends of capacitor C56, the other ends of bidirectional TVS diode TVS1, and one end of inductor L10 are all connected to SGND (ground terminal). The other end of inductor L10 is electrically connected to the other end of capacitor C55. One end and the other end of capacitor C55 are both electrically connected to the external sensor.

5. A switching power supply compatible with different external sensors according to claim 1, characterized in that: The external voltage conversion module includes capacitor C49, transformer T3, capacitor C52, resistor R100, diode D20, capacitor CE6, resistor R102, capacitor C53, and capacitor C54; the opposite-name terminal of the primary side of transformer T3 is electrically connected to the output terminal of the main circuit, the same-name terminal of the primary side of transformer T3 is connected to GND ground, and capacitor C49 is connected in parallel between the same-name terminal and the opposite-name terminal of the primary side of transformer T3. The same-name terminal on the secondary side of transformer T3 and one end of capacitor C52 are electrically connected to the anode of diode D20. The other end of capacitor C52 is electrically connected to one end of resistor R100. The other end of resistor R100, the cathode of diode D20, the positive terminal of capacitor CE6, and one end of resistor R102 are all electrically connected to one end of capacitor C53. The opposite-name terminal on the secondary side of transformer T3, the negative terminal of capacitor CE6, the other end of resistor R102, the other end of capacitor C53, and one end of capacitor C54 are all connected to SGND ground. The other ends of capacitor C53 and capacitor C54 are both electrically connected to the external detection access module.

6. A switching power supply compatible with different external sensors according to claim 1, characterized in that: The external detection feedback module includes resistor R121, capacitor C64, resistor R125, optocoupler U21, resistor R126, capacitor C65, and resistor R124. The anode of the light source of optocoupler U21 is electrically connected to the external detection access module via resistor R121, and the cathode of the light source of optocoupler U21 is connected to the SGND ground terminal. Resistor R125 and capacitor C64 are connected in parallel between the anode and cathode of the light source of optocoupler U21. The collector of the photodetector U21 is connected to a 3V3 power supply. The emitter of the photodetector U21 is electrically connected to the microcontroller via the resistor R124. The emitter of the photodetector U21 is connected to the GND ground terminal. The resistor R126 and the capacitor C65 are connected in parallel between the emitter of the photodetector U21 and the GND ground terminal.

7. A switching power supply compatible with different external sensors according to claim 2, characterized in that: The internal voltage conversion module includes a voltage regulator chip U10, an AC / DC constant voltage chip U11, capacitors C38, CE1, C40, CE2, C44, CE4, C39, C36, and C41, a resistor R77, a diode D14, a transformer T2, resistors R86 and R87, diodes D15 and D16, and a Zener diode DZ2. The drain terminal of the power transistor of the AC / DC constant voltage chip U11 is used as the input terminal of the internal voltage conversion module, the output terminal of the voltage regulator chip U10 is used as the first output terminal of the internal voltage conversion module, and the non-polarized terminal on the primary side of the transformer T2 is used as the second output terminal of the internal voltage conversion module. One end of capacitor C36 and one end of capacitor C41 are both electrically connected to the drain terminal of the power transistor of AC / DC constant voltage chip U11. The other end of capacitor C41 is connected to GND. The other end of capacitor C36, the anode of diode D15, the positive terminal of capacitor CE4, one end of capacitor C44, and one end of resistor R86 are all electrically connected to the opposite-name terminal of the primary side of transformer T2. The cathode of diode D15 is electrically connected to the cathode of Zener diode DZ2. One end of capacitor C39, the VCC terminal of AC / DC constant voltage chip U11, and the A The voltage selection terminal of the AC / DC constant voltage chip U11 is electrically connected to the anode of the Zener diode DZ2. The GND terminal of the AC / DC constant voltage chip U11, the other end of the capacitor C39, and the cathode of the diode D16 are all electrically connected to the same terminal on the primary side of the transformer T2. The current sampling terminal of the AC / DC constant voltage chip U11 is electrically connected to the GND terminal of the AC / DC constant voltage chip U11 through the resistor R87. The anode of the diode D16, the cathode of the capacitor CE4, the other end of the capacitor C44, and the other end of the resistor R86 are all connected to the GND ground terminal. The same-name terminal of the secondary side of the transformer T2 is electrically connected to the anode of the diode D14. The cathode of the diode D14 is electrically connected to the input terminal of the voltage regulator chip U10 through the resistor R77. The GND terminal of the voltage regulator chip U10 is connected to the SGND ground terminal. The capacitor C40 and the capacitor CE2 are connected in parallel between the input terminal and the SGND ground terminal of the voltage regulator chip U10. The capacitor C38 and the capacitor CE1 are connected in parallel between the output terminal and the SGND ground terminal of the voltage regulator chip U10.

8. A switching power supply compatible with different external sensors according to claim 2, characterized in that: The switching module includes resistors R78, R80, R76, and R45, capacitor C37, transistor Q7, and MOSFET Q4; one end of resistor R78 is used as the control terminal of the switching module, the drain of MOSFET Q4 is used as the input terminal of the switching module, and the source of MOSFET Q4 is used as the output terminal of the switching module. The other end of resistor R78 is electrically connected to the base of transistor Q7. The collector of transistor Q7 is electrically connected to the gate of MOSFET Q4. The emitter of transistor Q7 is connected to GND. Resistor R80 and capacitor C37 are connected in parallel between the base of transistor Q7 and GND. Resistor R76 is connected in parallel between the collector of transistor Q7 and GND. Resistor R45 is connected in parallel between the gate and drain of MOSFET Q4.

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