Primary side control circuit, PCB and guide rail power supply

Abstract

The utility model discloses a primary side control circuit, a PCB and a guide rail power supply. The primary side control circuit is composed of an input processing unit, a primary side flyback unit, a dial-up unit, a primary side control unit, an output processing unit and a transformer T1. The input processing unit is connected with an external power supply, and the output end of the input processing unit, the energy storage end of the primary flyback unit, the voltage dividing end of the primary control unit and the primary coil of the transformer T1 are sequentially connected. A primary coil of the transformer T1 is connected with the input end of the output processing unit, and the output end of the output processing unit is connected with electric equipment. The output end of the dial unit is connected with the dimming end of the primary side control unit, and the enabling end of the primary side control unit is connected with the feedback end of the primary side flyback unit; according to the primary side control circuit disclosed by the invention, the dial-up function is realized through the primary side, so that the circuit structure is simplified, the manufacturing cost is reduced, and the reliability and the stability of the circuit are improved; in addition, the system has the advantages of convenience in debugging and maintenance, high compatibility, energy conservation and high efficiency.

Description

Technical Field

[0001] This utility model relates to the field of circuit design technology, and in particular to a primary-side control circuit, PCB board and rail power supply. Background Technology

[0002] Din-rail power supplies, also known as DIN rail power supplies, are a type of switching power supply. Their design feature is that they can be installed on a DIN rail to provide stable and reliable power support for various electrical devices. This power supply system mainly consists of power modules, output modules, control modules, and power components. It plays an important role in industrial automation, power systems, and control engineering, and is favored for its convenient installation and flexible use.

[0003] When designing a DIN rail power supply, DIP switches can be used to set the output current level. For example, a DIN rail power supply may have multiple output current options, such as 1A, 2A, 5A, etc. Through different combinations of DIP switches, users can easily select the required output current without changing any software settings or making complex configurations. This setting method is simple and intuitive, facilitates quick on-site adjustments, and can meet the power supply needs of different devices.

[0004] Traditional DIN rail power supply designs typically rely on secondary DC / DC conversion technology to achieve DIP switch regulation of the output current. While this method can meet basic regulation needs to a certain extent, its drawbacks are becoming increasingly apparent. First, during the secondary DC / DC conversion process, unnecessary heat is generated due to conversion efficiency limitations. This not only reduces the overall energy efficiency ratio but may also require additional heat dissipation equipment, thereby increasing system complexity and cost. Second, the DIP switches and related circuit components used in secondary DC / DC solutions are often expensive. Coupled with the additional heat dissipation costs due to low energy efficiency, overall cost control becomes a crucial issue that designers must address.

[0005] It is evident that existing technologies still need improvement and enhancement. Utility Model Content

[0006] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a primary-side control circuit that realizes the DIP switch function through the primary side. This not only simplifies the circuit design and reduces the production cost, but also improves the reliability and stability of the circuit. At the same time, it is easy to debug and maintain, has wide compatibility, and can achieve energy saving and high efficiency.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A primary-side control circuit includes an input processing unit, a primary-side flyback unit, a DIP switch unit, a primary-side control unit, an output processing unit, and a transformer T1. The input terminal of the input processing unit is used to connect to an external power supply device. The output terminal of the input processing unit, the energy storage terminal of the primary-side flyback unit, the voltage divider terminal of the primary-side control unit, and the primary coil of the transformer T1 are connected in sequence. The primary coil of the transformer T1 is connected to the input terminal of the output processing unit. The output terminal of the output processing unit is used to connect to electrical equipment. The output terminal of the DIP switch unit is connected to the dimming terminal of the primary-side control unit, and the enable terminal of the primary-side control unit is connected to the feedback terminal of the primary-side flyback unit.

[0009] In the primary-side control circuit, the input processing unit includes an electromagnetic suppression section and a rectifier-filter section. The input terminal of the electromagnetic suppression section is used to connect to an external power supply device, the output terminal of the electromagnetic suppression section is connected to the input terminal of the rectifier-filter section, and the output terminal of the rectifier-filter section is connected to the energy storage terminal of the primary-side flyback unit.

[0010] The primary-side control circuit also includes a power supply unit. The input terminal of the power supply unit is inducedly connected to the primary coil of the transformer T1, and the output terminal of the power supply unit is connected to the power supply terminal of the primary-side control unit and the power supply terminal of the primary-side flyback unit.

[0011] In the primary-side control circuit, the primary-side flyback unit includes a first control chip U1, an energy storage unit, and a feedback unit. The first control chip U1's pin D is connected to the energy storage unit, the first control chip U1's pin F1 is connected to the enable terminal of the primary-side control unit through the feedback unit, and the first control chip U1's pin VCC is connected to the output terminal of the power supply unit.

[0012] In the primary-side control circuit, the primary-side flyback unit further includes a first sampling section. One end of the first sampling section is connected to pin CS of the first control chip U1, and the other end of the first sampling section is connected to the power supply unit.

[0013] In the primary-side control circuit, the primary-side control unit includes a voltage divider and a second control chip U2. The DRAIN pin of the second control chip U2 is connected to the primary coil of the transformer T1 through the voltage divider. The DIM pin of the second control chip U2 is connected to the output terminal of the DIP switch unit. The VCC pin of the second control chip U2 is connected to the output terminal of the power supply unit. The STB pin of the second control chip U2 is connected to the FB pin of the first control chip U1 through the feedback unit.

[0014] In the primary-side control circuit, the primary-side control unit further includes a second sampling section and an overvoltage protection section. The pin CS of the second control chip U2 is connected to the voltage divider section through the second sampling section, and the pin ROVP of the second control chip U2 is connected to the output terminal of the power supply unit through the overvoltage protection section.

[0015] In the primary-side control circuit, the output processing unit includes a secondary coil of transformer T1, a rectifier section, and a filter section. The secondary coil of transformer T1 is induced to be connected to the primary coil of transformer T1. The secondary coil of transformer T1 is also connected to the input terminal of the rectifier section. The output terminal of the rectifier section is connected to the input terminal of the filter section. The output terminal of the filter section is used to connect to electrical equipment.

[0016] This utility model also provides a PCB board, on which the primary-side control circuit as described above is printed.

[0017] This utility model also provides a rail power supply, which uses any of the above-described primary-side control circuits to achieve operation control.

[0018] Beneficial effects:

[0019] This invention provides a primary-side control circuit that implements a DIP switch function via the primary side. This design not only simplifies the circuit structure and reduces manufacturing costs but also improves the reliability and stability of the circuit. Furthermore, it offers advantages such as convenient debugging and maintenance, strong compatibility, and energy efficiency. Specifically, the input terminal of the input processing unit is connected to an external power supply. After preprocessing, electrical energy sequentially passes through the energy storage terminal of the primary-side flyback unit, the voltage divider terminal of the primary-side control unit, and the primary coil of transformer T1, and is finally output to the electrical equipment by the output processing unit. The output terminal of the DIP switch unit is connected to the dimming terminal of the primary-side control unit, allowing users to flexibly adjust the circuit output according to their needs. Simultaneously, the enable terminal of the primary-side control unit is connected to the feedback terminal of the primary-side flyback unit, forming a closed-loop control to ensure stable circuit operation. Attached Figure Description

[0020] Figure 1 A circuit block diagram of the primary-side control circuit provided by this utility model;

[0021] Figure 2 The circuit diagram of the primary-side control circuit provided by this utility model.

[0022] Explanation of key component symbols: 1-Input processing unit, 11-Electromagnetic suppression section, 12-Rectifier and filter section, 2-Primary-side flyback unit, 21-Energy storage section, 22-Feedback section, 23-First sampling section, 3-DIP switch unit, 4-Primary-side control unit, 41-Voltage divider section, 42-Second sampling section, 43-Overvoltage protection section, 5-Output processing unit, 51-Rectifier section, 52-Filter section, 6-Power supply unit. Detailed Implementation

[0023] This utility model provides a primary-side control circuit, a PCB board, and a rail power supply. To make the purpose, technical solution, and effects of this utility model clearer and more explicit, the following describes this utility model in further detail with reference to the accompanying drawings and embodiments.

[0024] In the description of this utility model, it should be understood that the terms "installation" and "connection" should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] Please see Figure 1 and Figure 2 This utility model provides a primary-side control circuit, including an input processing unit 1, a primary-side flyback unit 2, a DIP switch unit 3, a primary-side control unit 4, an output processing unit 5, and a transformer T1. The input terminal of the input processing unit 1 is used to connect to an external power supply device. The output terminal of the input processing unit 1, the energy storage terminal of the primary-side flyback unit 2, the voltage divider terminal of the primary-side control unit 4, and the primary coil of the transformer T1 are connected in sequence. The primary coil of the transformer T1 is connected to the input terminal of the output processing unit 5, and the output terminal of the output processing unit 5 is used to connect to electrical equipment. The output terminal of the DIP switch unit 3 is connected to the dimming terminal of the primary-side control unit 4, and the enable terminal of the primary-side control unit 4 is connected to the feedback terminal of the primary-side flyback unit 2.

[0026] The primary-side control circuit disclosed in this application implements the DIP switch function through the primary side. This design not only simplifies the circuit structure and reduces manufacturing costs, but also improves the reliability and stability of the circuit. Furthermore, it offers advantages such as convenient debugging and maintenance, strong compatibility, and energy efficiency. Specifically, the input terminal of the input processing unit 1 is connected to an external power supply. After preprocessing, electrical energy sequentially passes through the energy storage terminal of the primary-side flyback unit 2, the voltage divider terminal of the primary-side control unit 4, and the primary coil of transformer T1, and is finally output to the electrical equipment by the output processing unit 5. The output terminal of the DIP switch unit 3 is connected to the dimming terminal of the primary-side control unit 4, allowing users to flexibly adjust the circuit output according to their needs. Simultaneously, the enable terminal of the primary-side control unit 4 is connected to the feedback terminal of the primary-side flyback unit 2, forming a closed-loop control to ensure stable circuit operation.

[0027] Further, please refer to Figure 1 and Figure 2 The input processing unit 1 includes an electromagnetic suppression unit 11 and a rectifier filter unit 5212. The input terminal of the electromagnetic suppression unit 11 is used to connect to an external power supply device. The output terminal of the electromagnetic suppression unit 11 is connected to the input terminal of the rectifier filter unit 5212. The output terminal of the rectifier filter unit 5212 is connected to the energy storage terminal of the primary-side flyback unit 2.

[0028] In the embodiments of this city, please refer to Figure 2 The electromagnetic suppression unit 11 includes a first varistor VR1, a safety capacitor CX1, and a first excitation coil LF1. The rectifier and filter unit 5212 includes a first resistor R1, a first inductor L1, a rectifier bridge BD1, and a first capacitor CB1. The first varistor VR1 is used to connect to an external power supply device, which is AC mains power. The first varistor VR1 is connected to one end of the first excitation coil LF1 through the safety capacitor CX1. The other end of the first excitation coil LF1 is connected to the input terminal of the rectifier bridge BD1 through the first resistor R1 and the first inductor L1 connected in parallel. The output terminal of the rectifier bridge BD1 is connected to the input terminal of the energy storage unit 21 and one end of the first capacitor CB1, respectively. The other end of the first capacitor CB1 is grounded.

[0029] In this embodiment, the electromagnetic suppression unit 11 effectively suppresses electromagnetic interference introduced by the external power supply device, protecting the stability and safety of the circuit. The first varistor VR1 absorbs transient overvoltages, preventing the circuit from being impacted by overvoltage. The safety capacitor CX1 and the first excitation coil LF1 filter out high-frequency noise, further enhancing the electromagnetic suppression effect. The rectifier filter unit 5212 converts the AC power supplied by the external power supply device into stable DC power for use by the primary-side flyback unit 2 and the primary-side control. The first resistor R1 and the first inductor L1 form a current-limiting filter circuit, limiting current surges and protecting the rectifier bridge BD1. The rectifier bridge BD1 converts AC power into DC power. The first capacitor CB1 acts as a smoothing filter, ensuring the stability of the output voltage.

[0030] Further, please refer to Figure 1 and Figure 2 The primary-side control circuit also includes a power supply unit 6. The input terminal of the power supply unit 6 is inducedly connected to the primary coil of the transformer T1, and the output terminal of the power supply unit 6 is connected to the power supply terminal of the primary-side control unit 4 and the power supply terminal of the primary-side flyback unit 2, respectively.

[0031] In this embodiment, please refer to Figure 2The power supply unit 6 includes an auxiliary coil of transformer T1, a tenth diode D10, a twenty-ninth resistor R29, a ninth diode D9, and a thirtieth resistor R30. The auxiliary coil of transformer T1 is inducedly connected to the primary coil of transformer T1. The auxiliary coil of transformer T1 is connected to the positive terminals of the tenth diode D10 and the ninth diode D9, respectively. The negative terminal of the tenth diode D10 is connected to the VCC pin of the second control chip U2 through the twenty-ninth resistor R29. The negative terminal of the ninth diode D9 is connected to the VCC pin of the first control chip U1 through the thirtieth resistor R30.

[0032] In this embodiment, a stable power supply is achieved for the primary-side control unit 4 and the primary-side flyback unit 2 by introducing a power supply unit 6. The auxiliary coil is induced to connect with the primary coil, and can sense the change in the electrical energy of the primary coil and convert it into auxiliary electrical energy. The rectifier-step-down circuit composed of the tenth diode D10 and the twenty-ninth resistor R29, and another rectifier-step-down circuit composed of the ninth diode D9 and the thirtieth resistor R30, respectively convert the auxiliary electrical energy into voltages suitable for the operation of the second control chip U2 and the first control chip U1, and supply power through their respective VCC pins.

[0033] Further, please refer to Figure 1 and Figure 2 The primary-side flyback unit 2 includes a first control chip U1, an energy storage unit 21, and a feedback unit 22. The first control chip U1's pin D is connected to the energy storage unit 21, the first control chip U1's pin F1 is connected to the enable terminal of the primary-side control unit 4 through the feedback unit 22, and the first control chip U1's pin VCC is connected to the output terminal of the power supply unit 6.

[0034] Further, please refer to Figure 1 and Figure 2 The primary-side flyback unit 2 further includes a first sampling unit 23, one end of which is connected to pin CS of the first control chip U1, and the other end of which is connected to the power supply unit 6.

[0035] In this embodiment, please refer to Figure 1The first control chip U1 is model BP2636CG. The energy storage unit 21 includes an eleventh capacitor C11, a first diode D1, a second inductor L2, a second diode D2, and a first filter capacitor EC1. The feedback unit 22 includes a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first sampling unit 23 includes a sixth resistor R6 and a seventh resistor R7. One end of the eleventh capacitor C11, the positive terminal of the first diode D1, and one end of the second inductor L2 are respectively connected to the output terminal of the rectifier bridge BD1. The other end of the eleventh capacitor C11, the negative terminal of the first diode D1, and the other end of the second inductor L2 are respectively connected to pins D and E1 of the first control chip U1. The positive terminal of the second diode D2 is connected to one end of the second resistor R2, the positive terminal of the first filter capacitor EC1, and the voltage divider 41. The other end of the second resistor R2 is connected to the pin FB of the first control chip U1 through the third resistor R3 and the fourth resistor R4 connected in series. One end of the fifth resistor R5 is connected to the pin FB of the first control chip U1, and the other end is connected to the pin STB of the second control chip U2. One end of the sixth resistor R6 and one end of the seventh resistor R7 are connected to the pin CS of the first control chip U1, and the other ends of the sixth resistor R6, the seventh resistor R7, and the negative terminal of the first filter capacitor EC1 are grounded.

[0036] In this embodiment, firstly, by setting the primary-side flyback unit 2, efficient power supply management and stable output are achieved. The first control chip U1, as a core component, connects to the energy storage unit 21 via its pin D, enabling precise control of the energy storage process and ensuring stable energy storage and release. Simultaneously, pin F1 connects to the enable terminal of the primary-side control unit 4 via the feedback unit 22, enabling real-time monitoring and feedback adjustment of the output signal, thereby ensuring output stability and accuracy. Secondly, the addition of the first sampling unit 23 further enhances the system's stability and security. By sampling the voltage at pin CS of the first control chip U1, the system can... The system monitors the power supply's operating status in real time, and can immediately take protective measures upon detecting any abnormalities, thus preventing equipment damage or safety accidents caused by power supply failures. Furthermore, the first control chip U1 selected in this embodiment is a BP2636CG, which has advantages such as high performance, low power consumption, and high reliability, and can meet the needs of various complex application scenarios. Finally, the specific circuit design of the energy storage unit 21, feedback unit 22, and first sampling unit 23 fully considers factors such as efficiency and stability, achieving precise control and protection of the power supply output, ensuring the excellent performance of the entire power supply system, and further improving the system's reliability and stability.

[0037] Further, please refer to Figure 1 and Figure 2 The primary control unit 4 includes a voltage divider 41 and a second control chip U2. The DRAIN pin of the second control chip U2 is connected to the primary coil of the transformer T1 through the voltage divider 41. The DIM pin of the second control chip U2 is connected to the output terminal of the DIP switch unit 3. The VCC pin of the second control chip U2 is connected to the output terminal of the power supply unit 6. The STB pin of the second control chip U2 is connected to the FB pin of the first control chip U1 through the feedback unit 22.

[0038] Further, please refer to Figure 1 and Figure 2 The primary control unit 4 further includes a second sampling unit 42 and an overvoltage protection unit 43. The pin CS of the second control chip U2 is connected to the voltage divider 41 through the second sampling unit 42, and the pin ROVP of the second control chip U2 is connected to the output terminal of the power supply unit 6 through the overvoltage protection unit 43.

[0039] In this embodiment, please refer to Figure 2The second control chip U2 is model BP3182EG. The voltage divider 41 includes a ninth resistor R9, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a fifth capacitor C5, an eighth diode D8, and an eighteenth resistor R18. The second sampling unit 42 includes a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and an eighth capacitor C8. The overvoltage protection unit 43 includes a twenty-eighth resistor R28. The DIP switch unit 3 includes a DIP switch SW1 and four resistor groups, each resistor... The group consists of two resistors connected in parallel; one end of the ninth resistor R9, one end of the thirteenth resistor R13, one end of the fourteenth resistor R14, one end of the fifteenth resistor R15, one end of the fifth capacitor C5, and pin 5 of the primary coil of the transformer T1 are respectively connected to the negative terminal of the second diode D2; the other end of the ninth resistor R9 is connected to pin HV of the second control chip U2; the other ends of the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, and the fifth capacitor C5 are connected to the negative terminal of the second diode D2. The terminals are respectively connected to one end of the sixteenth resistor R16 and one end of the seventeenth resistor R17. The other ends of the sixteenth resistor R16 and the seventeenth resistor R17 are respectively connected to the negative terminal of the eighth diode D8. The positive terminal of the eighth diode D8 is respectively connected to one end of the eighteenth resistor R18 and pin 3 of the primary coil of the transformer T1. The other end of the eighteenth resistor R18 is respectively connected to pin DRAIN of the second control chip U2 and one end of the eighth capacitor C8. The other end of the eighth capacitor C8 is respectively connected to the second control chip U2. The pin CS of the control chip U2, one end of the tenth resistor R10, one end of the eleventh resistor R11, and one end of the twelfth resistor R12 are connected; the four output terminals of the DIP switch SW1 are respectively connected to the pin DIM of the second control chip U2 through the four resistor groups; one end of the twenty-eighth resistor R28 is connected to the pin ROVP of the second control chip U2, and the other ends of the twenty-eighth resistor R28, the tenth resistor R10, the eleventh resistor R11, and the twelfth resistor R12 are respectively grounded.

[0040] In this embodiment, firstly, through the connection of the second control chip U2 with the voltage divider 41, the second sampling unit 42, the overvoltage protection unit 43, the DIP switch unit 3, and the feedback unit 22, and in coordination with the primary-side flyback unit 2, precise control of the primary coil voltage of transformer T1 is achieved, ensuring stable circuit output. The design of the voltage divider 41 can reasonably divide the high voltage into a low voltage suitable for processing by the second control chip U2, ensuring the safety and stability of the circuit. Secondly, the second sampling unit 42 can monitor the current of the primary coil of transformer T1 in real time and feed the sampling signal back to the second control chip U2 for current analysis. This design helps improve power conversion efficiency and protect the circuit from excessive current surges. Furthermore, the overvoltage protection unit 43 can promptly trigger the overvoltage protection function of the second control chip U2 when the output voltage of the power supply unit 6 rises abnormally, thereby preventing circuit damage and safety accidents. In addition, the design of the DIP switch unit 3 allows users to adjust the power supply output parameters, such as the output current, according to actual needs, improving the flexibility and applicability of the DIN rail power supply. The DIP switch unit disclosed in this embodiment includes a four-position DIP switch SW1, which, together with four resistor groups, can achieve 16 levels of fine adjustment of the output current.

[0041] Further, please refer to Figure 1 and Figure 2 The output processing unit 5 includes a secondary coil of transformer T1, a rectifier 51, and a filter 52. The secondary coil of transformer T1 is induced to be connected to the primary coil of transformer T1. The secondary coil of transformer T1 is also connected to the input terminal of the rectifier 51. The output terminal of the rectifier 51 is connected to the input terminal of the filter 52. The output terminal of the filter 52 is used to connect to electrical equipment.

[0042] In this embodiment, please refer to Figure 2 The rectifier section 51 includes a thirty-first resistor R31, a tenth capacitor C10, and a diode group, the diode group consisting of four diodes connected in parallel; the filter section 52 includes a second filter capacitor EC2 and a second excitation coil LF2. One end of the thirty-first resistor R31 and the positive terminal of the diode group are respectively connected to the secondary coil of the transformer T1, the other end of the thirty-first resistor R31 is connected to one end of the tenth capacitor C10, the other end of the tenth capacitor C10 and the negative terminal of the diode group are respectively connected to the positive terminal of the second filter capacitor EC2 and one end of the second excitation coil LF2, the other end of the second excitation coil LF2 is used to connect electrical equipment, the electrical equipment may be a lighting fixture or other functional component installed in the guide rail.

[0043] In this embodiment, the output processing unit 5 realizes the transmission and conversion of electrical energy through the inductive connection between the secondary coil and the primary coil of the transformer T1. The AC power output from the secondary coil is rectified by the rectifier 51 to convert the AC power into DC power. The rectifier 51 uses a diode group composed of four parallel diodes, which improves the rectification efficiency and current carrying capacity, and ensures the stable operation of the circuit. The rectified DC power is then filtered by the filter 52 to further smooth the DC power, reduce voltage fluctuations, and improve power quality. The filter 52, in cooperation with the second filter capacitor EC2 and the second excitation coil LF2, can filter out the ripple component in the DC power, ensuring that the power output to the electrical equipment is stable and reliable.

[0044] This utility model also provides a PCB board, on which the primary-side control circuit as described above is printed.

[0045] This utility model also provides a rail power supply, which uses any of the above-described primary-side control circuits to achieve operation control.

[0046] It is understood that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of this utility model, and all such substitutions or changes should fall within the protection scope of this utility model.

Claims

1. A primary-side control circuit, characterized by, The system includes an input processing unit, a primary-side flyback unit, a DIP switch unit, a primary-side control unit, an output processing unit, and a transformer T1. The input terminal of the input processing unit is used to connect to an external power supply device. The output terminal of the input processing unit, the energy storage terminal of the primary-side flyback unit, the voltage divider terminal of the primary-side control unit, and the primary coil of the transformer T1 are connected in sequence. The primary coil of the transformer T1 is connected to the input terminal of the output processing unit. The output terminal of the output processing unit is used to connect to electrical equipment. The output terminal of the DIP switch unit is connected to the dimming terminal of the primary-side control unit, and the enable terminal of the primary-side control unit is connected to the feedback terminal of the primary-side flyback unit.

2. A primary-side control circuit according to claim 1, characterized in that The input processing unit includes an electromagnetic suppression section and a rectifier-filter section. The input terminal of the electromagnetic suppression section is used to connect to an external power supply device, the output terminal of the electromagnetic suppression section is connected to the input terminal of the rectifier-filter section, and the output terminal of the rectifier-filter section is connected to the energy storage terminal of the primary-side flyback unit.

3. A primary-side control circuit according to claim 1, wherein It also includes a power supply unit, the input terminal of which is induced to the primary coil of the transformer T1, and the output terminal of which is connected to the power supply terminal of the primary-side control unit and the power supply terminal of the primary-side flyback unit.

4. A primary side control circuit according to claim 3, wherein, The primary-side flyback unit includes a first control chip U1, an energy storage unit, and a feedback unit. Pin D of the first control chip U1 is connected to the energy storage unit. Pin F1 of the first control chip U1 is connected to the enable terminal of the primary-side control unit through the feedback unit. Pin VCC of the first control chip U1 is connected to the output terminal of the power supply unit.

5. A primary side control circuit according to claim 4, wherein, The primary-side flyback unit further includes a first sampling section, one end of which is connected to pin CS of the first control chip U1, and the other end of which is connected to the power supply unit.

6. A primary-side control circuit according to claim 4, wherein The primary control unit includes a voltage divider and a second control chip U2. The DRAIN pin of the second control chip U2 is connected to the primary coil of the transformer T1 through the voltage divider. The DIM pin of the second control chip U2 is connected to the output terminal of the DIP switch unit. The VCC pin of the second control chip U2 is connected to the output terminal of the power supply unit. The STB pin of the second control chip U2 is connected to the FB pin of the first control chip U1 through the feedback unit.

7. A primary side control circuit according to claim 6, wherein, The primary control unit further includes a second sampling section and an overvoltage protection section. The CS pin of the second control chip U2 is connected to the voltage divider section through the second sampling section, and the ROVP pin of the second control chip U2 is connected to the output terminal of the power supply unit through the overvoltage protection section.

8. The primary-side control circuit of claim 1, wherein, The output processing unit includes a secondary coil of transformer T1, a rectifier section, and a filter section. The secondary coil of transformer T1 is inducedly connected to the primary coil of transformer T1. The secondary coil of transformer T1 is also connected to the input terminal of the rectifier section. The output terminal of the rectifier section is connected to the input terminal of the filter section. The output terminal of the filter section is used to connect to electrical equipment.

9. A PCB board characterized by, The PCB is printed with the primary side control circuit according to any one of claims 1-8.

10. A guideway power supply characterized by, The rail power supply is controlled by the primary side control circuit according to any one of claims 1-8.

Images