Lightning protection switching power supply circuit
By adding a current limiting resistor to the switching power supply circuit to protect the AC rectifier diode, the problem that AC rectifier diodes are easily broken down when struck by lightning in the prior art is solved, and the lightning resistance of the switching power supply is improved.
Patent Information
- Application Number
- CN202420473169.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-12
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-03-12
AI Technical Summary
When the existing switching power supply circuit is struck by lightning, the AC rectifier diode is easily broken down by lightning surge current and fails.
The first current limiting resistor and the second current limiting resistor are added to the switching power supply circuit to provide current limit protection for the AC rectifier diode, thereby improving the resistance to lightning surges.
By increasing the current limiting resistance, the AC rectifier diode is effectively prevented from being broken down during lightning strikes, improving the lightning resistance of the switching power supply.
Smart Images
Figure CN222602268U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of switch power supply, in particular to a switch power supply circuit for lightning protection. Background Art
[0002] Switching power supply is particularly important in LED flat-panel TVs. LLC circuits in switching power supplies are widely used due to their superior performance. Existing LLC circuits usually use high-voltage half-wave starting, such as Figure 1 As shown, the chip U1 includes a VSENSE pin, the second pin of the chip U1 is the VSENSE pin, i.e., the bo-in / out control pin, the third pin is the HV pin, i.e., the high voltage start pin, the AC live wire ACL is connected to one end of the first diode D1, the AC neutral wire ACN is connected to one end of the second diode, the other end of the first diode is connected to the other end of the second diode D2, the other end of the first diode is connected to the second pin through resistors R1, R4 and R5, the other end of the second diode D2 is connected to the third pin through resistors R2, R3 and R6, and during the lightning strike experiment of the LLC circuit, the AC rectifier diodes D1 and D2 are easily broken down by the lightning surge current and fail. Utility Model Content
[0003] The technical problem solved by the utility model is to provide a lightning protection switching power supply circuit to solve the problem that when lightning strikes, the AC rectifier diode of the existing switching power supply circuit is easily broken down by the lightning surge current and fails.
[0004] The utility model adopts a technical solution to solve the above technical problems: a lightning protection switching power supply circuit, including a chip, an AC live wire, an AC neutral wire, a first diode, a second diode, a first current limiting resistor, a second current limiting resistor, a first voltage divider module and a first resistor; the chip includes a VSENSE pin and a HV pin, the AC live wire is connected to the positive end of the first diode, and the negative end of the first diode is connected to one end of the first current limiting resistor; the AC neutral wire is connected to the positive end of the second diode, and the negative end of the second diode is connected to one end of the second current limiting resistor, the other end of the first current limiting resistor is connected to the other end of the second current limiting resistor, and is connected to the VSENSE pin of the chip through the first voltage divider module, and is connected to the HV pin of the chip through the first resistor.
[0005] Furthermore, the first voltage dividing module includes a resistor.
[0006] Furthermore, the first voltage dividing module includes at least two resistors connected in series.
[0007] Furthermore, the chip model is HR1270.
[0008] The beneficial effects of the utility model are as follows: the utility model provides a lightning protection switching power supply circuit, which improves the lightning surge resistance of the switching power supply by adding corresponding current limiting resistors to two AC rectifier diodes in the existing switching power supply circuit, thereby solving the problem that the AC rectifier diodes of the switching power supply circuit are easily broken down by the lightning surge current and fail when lightning strikes. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a schematic diagram of an existing switching power supply circuit;
[0010] Figure 2 This is a schematic diagram of a lightning protection switch power supply circuit provided by the utility model;
[0011] ACL represents the AC live wire, ACN represents the AC neutral wire, D1 represents the first diode, D2 represents the second diode, R1 represents the resistor, R2 represents the first resistor, R3 represents the first current limiting resistor, R4 represents the second current limiting resistor, U1 represents the chip, VSENSE represents the second pin of the chip, and HV represents the third pin of the chip. DETAILED DESCRIPTION
[0012] The utility model aims to solve the problem that when a lightning strike occurs, the AC rectifier diode of the existing switching power supply circuit is easily broken down by the lightning surge current and fails. Figure 2 As shown, it includes a chip U1, an AC live wire ACL, an AC neutral wire ACN, a first diode D1, a second diode D2, a first current limiting resistor R3, a second current limiting resistor R4, a first voltage divider module and a first resistor R2; the chip U1 includes a VSENSE pin and a HV pin, the AC live wire ACL is connected to the positive end of the first diode D1, and the negative end of the first diode D1 is connected to one end of the first current limiting resistor R3; the AC neutral wire ACN is connected to the positive end of the second diode D2, and the negative end of the second diode D2 is connected to one end of the second current limiting resistor R4, the other end of the first current limiting resistor R3 is connected to the other end of the second current limiting resistor R4, and is connected to the VSENSE pin of the chip U1 through the first voltage divider module, and is connected to the HV pin of the chip U1 through the first resistor R2.
[0013] Specifically, during operation, the alternating current forms a loop through the CSENSE pin of the chip U1 and its internal structure after passing through the first voltage divider module. Thus, the voltage of the CSENSE pin of the chip U1 meets the circuit requirements by means of the first voltage divider module. In addition, the alternating current also provides a high voltage to the HV pin of the chip U1 through R2. When a lightning surge occurs, the protection of the two resistors by the first current limiting resistor R3 and the second current limiting resistor R4 improves the lightning surge resistance of the switching power supply.
[0014] Furthermore, the first voltage divider module includes a resistor. Specifically, the voltage divider module can be used as follows: Figure 1 The resistor R1 in.
[0015] Furthermore, the first voltage divider module includes at least two resistors connected in series. Specifically, a single resistor is used to reduce the voltage, and a relatively high withstand voltage value of the resistor is required. Therefore, the cost is relatively high. A plurality of resistors with relatively low withstand voltage values can be connected in series to reduce the cost.
[0016] Furthermore, the model of chip U1 is HR1270.
Claims
1. A lightning protection switching power supply circuit, characterized in that: The invention comprises a chip (U1), an alternating current live line (ACL), an alternating current neutral line (ACN), a first diode (D1), a second diode (D2), a first current limiting resistor (R3), a second current limiting resistor (R4), a first voltage divider module and a first resistor (R2); the chip (U1) comprises a VSENSE pin and an HV pin, the alternating current live line (ACL) is connected to the positive end of the first diode (D1), and the negative end of the first diode (D1) is connected to one end of the first current limiting resistor (R3); the alternating current neutral line (ACN) is connected to the positive end of the second diode (D2), and the negative end of the second diode (D2) is connected to one end of the second current limiting resistor (R4); the other end of the first current limiting resistor (R3) is connected to the other end of the second current limiting resistor (R4), and is connected to the VSENSE pin of the chip (U1) through the first voltage divider module, and is connected to the HV pin of the chip (U1) through the first resistor (R2).
2. The lightning protection switching power supply circuit according to claim 1, characterized in that: The first voltage dividing module includes a resistor.
3. The lightning protection switching power supply circuit according to claim 1, characterized in that: The first voltage dividing module includes at least two resistors connected in series.
4. The lightning protection switching power supply circuit according to any one of claims 1 to 3, characterized in that: The model of the chip (U1) is HR1270.