Voltage division type clamping circuit

Abstract

The invention relates to the technical field of switching power supplies, and discloses a voltage division type clamping circuit which comprises a switching transformer, a clamping assembly and a switching tube Q1, and the clamping assembly is composed of a diode D1, a diode D2, an additional winding N2 and a capacitor C1. According to the voltage division type clamping circuit, voltage division is carried out through the center tap of the additional winding N2, electric energy is absorbed and stored in the capacitor C1, and the clamping protection effect is achieved; when the switch tube Q1 is conducted, absorbed electric energy is released to the switch transformer, the energy is fully utilized, and compared with a common RCD clamping circuit, the switching power supply conversion efficiency of the RCD clamping circuit is improved.

Description

Technical Field

[0001] This invention relates to the field of switching power supply technology, and in particular to a voltage divider clamping circuit. Background Technology

[0002] Among the many switching power supply circuit topologies, there is a commonly used RCD clamping circuit that plays an important protective role. The RCD clamping circuit absorbs electrical energy, and the absorbed electrical energy is released through a resistor, resulting in significant energy loss and low conversion efficiency of the switching power supply. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a voltage divider clamping circuit. This voltage divider clamping circuit utilizes the center tap of the additional winding N2 to divide the voltage and absorb electrical energy into capacitor C1 for storage, thus achieving clamping protection. When the switching transistor Q1 is turned on, the absorbed electrical energy is released to the switching transformer, ensuring full energy utilization. Compared to commonly used RCD clamping circuits, its switching power supply conversion efficiency is improved.

[0004] The specific technical solution of the present invention is as follows: a voltage divider clamping circuit, including a switching transformer, a clamping assembly, and a switching transistor Q1.

[0005] The switching transformer consists of a primary winding N1, an auxiliary winding N2, a magnetic core, and a secondary winding N3.

[0006] The clamping assembly consists of diode D1, diode D2, additional winding N2, and capacitor C1.

[0007] The additional winding N2 is provided with a center tap b3.

[0008] The internal connection relationship of the voltage divider clamping circuit is as follows: the negative terminal of diode D1, the a1 terminal of the primary winding N1, and the b1 terminal of the auxiliary winding N2 are all connected to the positive terminal IN+ of the DC input. The positive terminal of diode D1 is connected to the negative terminal of diode D2 and then to one end of capacitor C1. The other end of capacitor C1 is connected to the center tap b3 of the auxiliary winding N2. The positive terminal of diode D2 is connected to the source of switching transistor Q1 and then to the negative terminal IN- of the DC input. The drain of switching transistor Q1 is connected to the b2 terminal of the auxiliary winding N2 and then to the a2 terminal of the primary winding N1. The gate of switching transistor Q1 is connected to the control signal H1.

[0009] In this context, the a1 terminal of the primary winding N1 and the b1 terminal of the auxiliary winding N2 of the switching transformer are terminals with the same name.

[0010] Wherein, the switching transistor Q1 is an NMOS field-effect transistor Q1.

[0011] The specific working process of a voltage divider clamping circuit according to the present invention is as follows: When the control signal H1 is high, the switching transistor Q1 is turned on, and the electrical energy provided by the positive terminal IN+ of the DC input supplies power to the switching transformer. The current flows out from the positive terminal IN+ of the DC input → primary winding N1 → switching transistor Q1 → negative terminal IN- of the DC input, forming the first power supply circuit. At the same time, the auxiliary winding N2 acts as a shunt, and the current flows out from the positive terminal IN+ of the DC input → auxiliary winding N2 → switching transistor Q1 → negative terminal IN- of the DC input, forming the second power supply circuit. Simultaneously, capacitor C1 discharges, and the current flows out from capacitor C1 → center tap b3 of auxiliary winding N2 → b2 of auxiliary winding N2 → switching transistor Q1 → diode D2 → capacitor C1, forming a discharge circuit. The primary winding N1 and auxiliary winding N2 are simultaneously energized, generating a magnetic field. According to the principle of electromagnetic induction, energy is transferred through the magnetic core of the switching transformer to the secondary winding N3 to output electrical energy to the load. When the control signal H1 is low, the switching transistor Q1 is turned off, and the switching transformer immediately performs an automatic magnetic reset. According to the back electromotive force principle, the voltage at terminal a2 of the primary winding N1 and terminal b2 of the auxiliary winding N2 increases, and the current flows through terminal a2 of the primary winding N1 → terminal b2 of the auxiliary winding N2 → center tap b3 of the auxiliary winding N2 → capacitor C1 → diode D1 → terminal a1 of the primary winding N1 to form the first magnetic reset circuit. The current flows through center tap b3 of the auxiliary winding N2 → capacitor C1 → diode D1 → terminal b1 of the auxiliary winding N2 to form the second magnetic reset circuit. At the same time, the magnetic core of the switching transformer releases energy to the secondary winding N3 to output electrical energy to the load.

[0012] The beneficial effects of this invention are as follows: The present invention provides a voltage divider clamping circuit that uses the center tap of the additional winding N2 to divide the voltage and absorb electrical energy into the capacitor C1 for storage, thereby achieving a clamping protection function. When the switching transistor Q1 is turned on, the absorbed electrical energy is released to the switching transformer, and the energy is fully utilized. Compared with the commonly used RCD clamping circuit, its switching power supply conversion efficiency is improved. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a voltage divider clamping circuit according to the present invention. Detailed Implementation

[0014] The technology of the present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0015] like Figure 1 As shown, a voltage divider clamping circuit includes a switching transformer, a clamping assembly, and a switching transistor Q1. The switching transformer consists of a primary winding N1, an auxiliary winding N2, a magnetic core, and a secondary winding N3. The clamping assembly consists of diode D1, diode D2, additional winding N2, and capacitor C1. The additional winding N2 is provided with a center tap b3; The internal connection relationship of the voltage divider clamping circuit is as follows: the negative terminal of diode D1, the a1 terminal of primary winding N1, and the b1 terminal of auxiliary winding N2 are all connected to the positive terminal IN+ of DC input; the positive terminal of diode D1 is connected to the negative terminal of diode D2 and then to one end of capacitor C1; the other end of capacitor C1 is connected to the center tap b3 of auxiliary winding N2; the positive terminal of diode D2 is connected to the source of switching transistor Q1 and then to the negative terminal IN- of DC input; the drain of switching transistor Q1 is connected to the b2 terminal of auxiliary winding N2 and then to the a2 terminal of primary winding N1; and the gate of switching transistor Q1 is connected to the control signal H1. In this embodiment, the a1 terminal of the primary winding N1 and the b1 terminal of the auxiliary winding N2 of the switching transformer are terminals with the same name. In this embodiment, the switching transistor Q1 is an NMOS field-effect transistor Q1; The specific working process of a voltage divider clamping circuit according to the present invention is as follows: When control signal H1 is high, switch Q1 is turned on, and the electrical energy provided by the positive terminal IN+ of the DC input supplies power to the switching transformer. The current flows out from the positive terminal IN+ of the DC input → primary winding N1 → switch Q1 → negative terminal IN- of the DC input, forming the first power supply circuit. At the same time, the auxiliary winding N2 acts as a shunt, and the current flows out from the positive terminal IN+ of the DC input → auxiliary winding N2 → switch Q1 → negative terminal IN- of the DC input, forming the second power supply circuit. Simultaneously, capacitor C1 discharges, and the current flows out from capacitor C1 → center tap b3 of auxiliary winding N2 → b2 of auxiliary winding N2 → switch Q1 → diode D2 → capacitor C1, forming a discharge circuit. The primary winding N1 and auxiliary winding N2 are simultaneously energized to generate a magnetic field. According to the principle of electromagnetic induction, energy is transferred through the magnetic core of the switching transformer to the secondary winding N3 to output electrical energy to the load. When the control signal H1 is low, the switching transistor Q1 is turned off, and the switching transformer immediately performs an automatic magnetic reset. According to the back electromotive force principle, the voltage at terminal a2 of the primary winding N1 and terminal b2 of the auxiliary winding N2 increases, and the current flows through terminal a2 of the primary winding N1 → terminal b2 of the auxiliary winding N2 → center tap b3 of the auxiliary winding N2 → capacitor C1 → diode D1 → terminal a1 of the primary winding N1 to form the first magnetic reset circuit. The current flows through center tap b3 of the auxiliary winding N2 → capacitor C1 → diode D1 → terminal b1 of the auxiliary winding N2 to form the second magnetic reset circuit. At the same time, the magnetic core of the switching transformer releases energy to the secondary winding N3 to output electrical energy to the load.

[0016] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0017] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A voltage divider clamping circuit, characterized in that: Includes switching transformer, clamping assembly, and switching transistor Q1; The switching transformer consists of a primary winding N1, an auxiliary winding N2, a magnetic core, and a secondary winding N3. The clamping assembly consists of diode D1, diode D2, additional winding N2, and capacitor C1. The additional winding N2 is provided with a center tap b3; The internal connection relationship of the voltage divider clamping circuit is as follows: the negative terminal of diode D1, the a1 terminal of primary winding N1, and the b1 terminal of auxiliary winding N2 are all connected to the positive terminal IN+ of DC input; the positive terminal of diode D1 is connected to the negative terminal of diode D2 and then to one end of capacitor C1; the other end of capacitor C1 is connected to the center tap b3 of auxiliary winding N2; the positive terminal of diode D2 is connected to the source of switching transistor Q1 and then to the negative terminal IN- of DC input; the drain of switching transistor Q1 is connected to the b2 terminal of auxiliary winding N2 and then to the a2 terminal of primary winding N1; and the gate of switching transistor Q1 is connected to the control signal H1. Wherein, the a1 end of the primary winding N1 and the b1 end of the auxiliary winding N2 of the switching transformer are terminals with the same name; Wherein, the switching transistor Q1 is an NMOS field-effect transistor Q1.

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