Positive and negative voltage output circuit based on coreless transformer isolation

Abstract

The utility model relates to the technical field of electronic power, in particular to a positive and negative voltage output circuit based on coreless transformer isolation, which comprises a cross-coupled oscillation circuit, a coreless transformer and a rectification filter circuit, the cross-coupled oscillation circuit generates sine wave oscillation, and energy is transmitted to a secondary coil through a primary coil of the coreless transformer. The secondary coil adopts a center tap structure, the rectification filter circuit receives signals transmitted by the secondary coil, and stable positive and negative voltage output is realized through rectification and filtering processing. High-efficiency energy transmission is realized through the coreless transformer, the voltage isolation capability is improved, electromagnetic interference is reduced, and the coreless transformer has the advantages of compact structure, low cost, high power density and the like, and is suitable for solid-state switch driving, high-frequency power conversion and other electronic power systems.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic power technical field, concretely relates to a positive and negative pressure output circuit based on coreless transformer isolation. BACKGROUND

[0002] In modern power electronic systems, solid-state switching devices (such as IGBT, MOSFET, SiC MOSFET, etc.) have become the core components of high-voltage and high-power applications. These devices are widely used in inverters, DC-DC converters, power amplifiers, and high-frequency converters, and their performance and reliability directly affect the operating efficiency of the entire system. In order to ensure the normal operation of solid-state switches, a stable and isolated driving power supply is needed to meet the driving requirements under different operating modes, while ensuring the safety and anti-interference ability of the system. In high-voltage power electronic systems, isolation driving technology is crucial, as it achieves electrical isolation between the high-voltage side and the low-voltage side to prevent high-voltage crosstalk, improve the electromagnetic compatibility (EMC) of the system, and ensure stable and reliable operation of the system.

[0003] Currently, isolation driving power supplies mainly use optical coupling isolation and traditional core transformer isolation technology. However, traditional isolation methods still have many shortcomings, such as aging problems with optical coupling, and large size and difficulty in integration with traditional core transformers, which limit the development of power electronic systems towards higher power density and higher efficiency. SUMMARY

[0004] The utility model aims at providing a positive and negative pressure output circuit based on coreless transformer isolation, which aims to improve the voltage isolation capability of electronic circuits, provide positive and negative voltage outputs for circuits, and solve the problem of difficulty in integrating circuits.

[0005] To achieve the above-mentioned purpose, the utility model provides a positive and negative pressure output circuit based on coreless transformer isolation, which is composed of a cross-coupled oscillation circuit, a planar coreless transformer, and a rectifier filter circuit connected in sequence. The cross-coupled oscillation circuit uses a DC power supply for input, and the planar coreless transformer and the rectifier filter circuit form an output circuit.

[0006] The cross-coupled oscillation circuit includes transistors M1 and M2, resonant capacitor C1, and resonant inductor L1. The gate and source of transistors M1 and M2 are cross-connected, and two groups of resonant inductors L1 are connected in series and connected in parallel with resonant capacitor C1.

[0007] The rectifier filter circuit includes two output paths for positive and negative voltages, and is composed of a center-tapped transformer, rectifier diodes D1 and D2, and filter capacitors C2 and C3.

[0008] The planar coreless transformer includes a primary coil and two secondary coils. The transformer has a turns ratio of 1:1:1 and a planar spiral structure. The primary and secondary coils are stacked and completely overlap in the vertical direction.

[0009] The secondary coil is symmetrically wound, and a center tap is led out between the two windings to provide a symmetrical AC voltage signal.

[0010] The number of rectifier and filter circuits is the same as the number of secondary coils of the planar coreless transformer.

[0011] This invention provides a positive and negative voltage output circuit based on coreless transformer isolation, comprising a cross-coupled oscillation circuit, a coreless transformer, and a rectifier and filter circuit. The cross-coupled oscillation circuit generates sinusoidal oscillations, which transfer energy to the secondary coil through the primary coil of the coreless transformer. The secondary coil employs a center-tapped structure. The rectifier and filter circuit receives the signal transmitted from the secondary coil and, after rectification and filtering, achieves stable positive and negative voltage output. This invention achieves efficient energy transfer through a coreless transformer, improves voltage isolation capability, reduces electromagnetic interference, and has advantages such as compact structure, low cost, and high power density. It is suitable for solid-state switch drives, high-frequency power conversion, and other electronic power systems. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the principle structure of a positive and negative voltage output circuit based on coreless transformer isolation according to this utility model.

[0014] Figure 2 This is a schematic diagram of the model structure of the planar coreless transformer of this utility model.

[0015] Figure 3 This is a schematic diagram of the connection structure of the cross-coupled oscillation circuit of this utility model.

[0016] Figure 4 This is a schematic diagram of the connection structure of the positive and negative voltage rectifier output circuits of the rectifier filter circuit of this utility model. Detailed Implementation

[0017] 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 intended to explain this utility model, and should not be construed as limiting this utility model.

[0018] Please see Figures 1 to 3 This utility model provides a positive and negative voltage output circuit based on coreless transformer isolation, which is composed of a cross-coupled oscillation circuit, a planar coreless transformer and a rectifier filter circuit connected in sequence. The cross-coupled oscillation circuit uses DC power input, and the planar coreless transformer and the rectifier filter circuit constitute the output circuit.

[0019] The cross-coupled oscillation circuit includes transistors M1 and M2, resonant capacitor C1 and resonant inductor L1, wherein transistors M1 and M2 are cross-connected, and two sets of resonant inductors L1 are connected in series and simultaneously in parallel with resonant capacitor C1.

[0020] The planar coreless transformer includes a primary coil and two secondary coils. The transformer has a turns ratio of 1:1:1 and a planar spiral structure. The primary and secondary coils are stacked and are located in different layers of the planar PCB, completely overlapping in the vertical direction.

[0021] The secondary coil is symmetrically wound, and a center tap is led out between the two windings to provide a symmetrical AC voltage signal.

[0022] The rectifier and filter circuit includes rectifier diodes D1 and D2, output filter capacitors C2 and C3, and load RL. The number of rectifier and filter circuits is the same as the number of secondary coils of the planar coreless transformer.

[0023] In this embodiment, the cross-coupled oscillating circuit generates a stable sinusoidal signal. This sinusoidal signal passes through a coreless transformer, transferring energy from the primary coil to the secondary coil via electromagnetic coupling, thus achieving energy transfer. A rectifier and filter circuit is connected to the secondary winding of the coreless transformer. Its function is to receive the signal transmitted from the primary coil and filter the received signal. The secondary coils of the coreless transformer are connected together, with a center tap drawn between the coils, making it a center-tapped transformer. The output circuit uses the center tap as a reference ground, adding rectifier and filter circuits at the rear end of the transformer to convert the AC voltage signal into stable positive and negative DC voltages.

[0024] The circuit works as follows: First, the DC power supply powers the cross-coupled oscillator circuit. After the amplitude and phase conditions are met, the cross-coupled oscillator circuit generates a stable sine wave signal. This signal is coupled to the secondary coil through the primary coil of the coreless transformer. After passing through the rectifier and filter circuit, it outputs positive and negative voltages, ultimately providing a stable DC voltage for the system circuit.

[0025] Specifically, the cross-coupled oscillation circuit operates at 5V. Through its self-excited oscillation, the primary coil of the coreless transformer generates a high-frequency alternating magnetic field. This alternating magnetic field acts on the secondary coil of the coreless transformer via electromagnetic coupling, inducing a corresponding high-frequency AC voltage in the secondary coil. Because the secondary coil of the coreless transformer uses a center-tapped structure, the induced AC signal can be used as a reference ground to obtain two symmetrical AC signals.

[0026] These two AC signals enter the rectifier and filter circuit, where they are rectified by rectifier diodes to convert the AC signals into DC signals. The signals are then further stabilized by capacitor filtering, resulting in a stable positive and negative voltage output.

[0027] Compared to traditional iron-core transformer isolation schemes, the planar coreless transformer structure adopted in this invention eliminates magnetic saturation problems and significantly reduces the influence of parasitic parameters, enabling the system to operate efficiently at high frequencies. Furthermore, through the self-excited oscillation characteristics of the cross-coupled oscillation circuit, efficient conversion can be achieved without external drive signals, reducing reliance on control circuits and simplifying system design.

[0028] In summary, this utility model has the following beneficial effects:

[0029] This invention proposes a coreless transformer-based positive and negative voltage output circuit that provides stable positive and negative DC output voltages. The circuit boasts advantages such as high voltage isolation, small size, and low cost. Furthermore, the coreless transformer structure eliminates the magnetic saturation problem of traditional iron-core transformers, while reducing the effects of leakage inductance and parasitic capacitance, enabling the system to maintain high efficiency and stability even at high frequencies. In addition, the circuit topology of this invention is simple, requiring no additional complex control circuitry, effectively reducing system design and manufacturing costs and improving overall reliability. This invention provides a new solution for the design of high-efficiency isolated drive power supplies.

[0030] The above description discloses only one or more preferred embodiments of the present utility model, and should not be construed as limiting the scope of the present utility model. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of the present utility model are still within the scope of the utility model.

Claims

1. A positive and negative voltage output circuit based on coreless transformer isolation, characterized in that, It consists of a cross-coupled oscillating circuit, a planar coreless transformer, and a rectifier and filter circuit connected in sequence. The cross-coupled oscillating circuit uses a DC power input, and the planar coreless transformer and the rectifier and filter circuit constitute the output circuit. The cross-coupled oscillation circuit includes transistors M1 and M2, resonant capacitor C1 and resonant inductor L1, wherein the gate and source of transistors M1 and M2 are cross-connected, and the two sets of resonant inductors L1 are connected in series and simultaneously connected in parallel with resonant capacitor C1. The rectifier and filter circuit includes two outputs: positive voltage and negative voltage. The rectifier and filter circuit consists of a center-tapped transformer, rectifier diodes D1 and D2, and filter capacitors C2 and C3.

2. The positive and negative voltage output circuit based on coreless transformer isolation as described in claim 1, characterized in that, The planar coreless transformer includes a primary coil and two secondary coils. The transformer has a turns ratio of 1:1:1 and a planar spiral structure. The primary and secondary coils are stacked and completely overlap in the vertical direction.

3. The positive and negative voltage output circuit based on coreless transformer isolation as described in claim 2, characterized in that, The secondary coil is symmetrically wound, and a center tap is led out between the two windings to provide a symmetrical AC voltage signal.

4. The positive and negative voltage output circuit based on coreless transformer isolation as described in claim 3, characterized in that, The number of rectifier and filter circuits is the same as the number of secondary coils of the planar coreless transformer.

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