Static conversion power supply circuit and device

Abstract

The utility model provides a static conversion power supply circuit and device, and relates to a power supply technology. The circuit comprises a direct current voltage division circuit, the input end of the direct current voltage division circuit is used for being connected with an external direct current voltage so as to output a positive direct current voltage and a negative direct current voltage at the output end of the direct current voltage division circuit; the input end of the sine wave output circuit is connected with the output end of the direct current voltage division circuit so as to output sine signals at the output end of the sine wave output circuit; the power supply input end of the three-phase voltage output circuit is connected with the output end of the direct current voltage division circuit, the signal input end of the three-phase voltage output circuit is connected with the output end of the sine wave output circuit, and the output end of the three-phase voltage output circuit is used for outputting three-phase alternating current voltage. According to the scheme, a circuit topological structure is optimized, so that static transformation voltage with low noise and quick response can be obtained.

Description

Technical Field

[0001] The present application relates to power supply technology, and in particular to a static variable power supply circuit and device. Background Art

[0002] A gyroscope is a sensor that senses changes in attitude. Specifically, it is a device that uses the momentum of a high-speed rotating body to sense the angular velocity of the shell relative to the inertial space around one or more axes orthogonal to the axis of rotation. To achieve high-speed rotation, a gyroscope requires a stable and reliable power supply. Usually, a statically variable power supply is used to provide the statically variable voltage required for the gyroscope to work.

[0003] Static variable power supplies generally convert one frequency of electric energy into another frequency of electric energy through rectification and inversion. There are two ways to achieve this conversion: rectification and inversion conversion (AC-DC-AC), and direct conversion from high-frequency electric energy to low-frequency electric energy (AC-AC, cyclic alternating current). Although conventional static variable power supplies can handle general situations, they cannot cope well with some gyroscopes that require higher static variable voltages, and there is currently no good solution to this problem. Utility Model Content

[0004] In order to solve the above problems, the present application provides a static variable power supply circuit and device, which can obtain a static variable voltage with low noise and fast response by optimizing the circuit topology.

[0005] This application is implemented as follows:

[0006] In the first aspect, the present application provides a static variable power supply circuit, which includes a DC voltage divider circuit, a sine wave output circuit and a three-phase voltage output circuit, wherein the sine wave output circuit includes a positive feedback circuit and an amplifier circuit. The input end of the DC voltage divider circuit is used to be connected to an external DC voltage so as to output a positive and a negative DC voltage at the output end of the DC voltage divider circuit, the input end of the amplifier circuit is connected to the output end of the DC voltage divider circuit so as to output a sinusoidal signal at the output end of the amplifier circuit, the input end of the positive feedback circuit is connected to the output end of the amplifier circuit, and the output end of the positive feedback circuit is connected to the input end of the amplifier circuit. The power input end of the three-phase voltage output circuit is connected to the output end of the DC voltage divider circuit, the signal input end of the three-phase voltage output circuit is connected to the output end of the sine wave output circuit, and the output end of the three-phase voltage output circuit is used to output a three-phase AC voltage.

[0007] Further, based on the above scheme, the DC voltage divider circuit includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, resistor R1, resistor R2, resistor R3, resistor R4 and yoke coil A14. The capacitor C2 and the capacitor C3 are connected in series and then connected in parallel with the capacitor C1, the common end of the capacitor C2 and the capacitor C1 is connected to the power input through the yoke coil A14, the resistor R1, the capacitor C4 and the resistor R3 are all connected in parallel with the capacitor C2, the resistor R2, the capacitor C5 and the resistor R4 are all connected in parallel with the capacitor C3, the common end of the capacitor C3 and the capacitor C1 is grounded through the yoke coil A14, the common end of the capacitor C4 and the capacitor C5 is grounded, the capacitor C6 is connected in parallel with the capacitor C1, the common end of the capacitor C6 and the capacitor C2 is used to output a positive DC voltage, and the common end of the capacitor C6 and the capacitor C3 is used to output a negative DC voltage.

[0008] Further, based on the aforementioned scheme, the sinusoidal wave output circuit includes a Zener diode V1, an operational amplifier U1, a variable resistor R12, a variable resistor R9, a variable resistor R16, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R10, a resistor R11, a resistor R13, a resistor R15, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11 and a capacitor C12. The positive electrode of the power supply of the operational amplifier U1 is connected to the common end of the capacitor C6 and the capacitor C2 through the resistor R5, the capacitor C7 and the capacitor C8 connected in parallel in pairs, and the negative electrode of the power supply of the operational amplifier U1 is connected to the common end of the capacitor C6 and the capacitor C3 through the resistor R6, the capacitor C9 and the capacitor C10 connected in parallel in pairs; the non-inverting input end of the operational amplifier U1 is grounded through the capacitor C12, and the non-inverting input end of the operational amplifier U1 is grounded through the resistor R8 and the variable resistor R9 connected in series in sequence, and the non-inverting input end of the operational amplifier U1 is also connected in series in sequence through the capacitors C11, the resistor R15, and the variable resistor R16 are connected to the output end of the operational amplifier U1; the inverting input end of the operational amplifier U1 is grounded through the resistor R10 and the resistor R7 connected in series in sequence, and the inverting input end of the operational amplifier U1 is also connected to the common end of the resistor R7 and the resistor R10 through the resistor R13, the variable resistor R12, the resistor R11 and the voltage-stabilizing diode V1 connected in series in sequence, and the common end of the resistor R13 and the variable resistor R12 is connected to the output end of the operational amplifier U1, and the output end of the operational amplifier U1 is used to output the sinusoidal signal Vi.

[0009] Further, based on the above scheme, the three-phase voltage output circuit includes a power chip U2 of JLDY-1000 model, a transformer T1, a transformer T2, a transformer T3, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C19, a capacitor C20 and a capacitor C21. Pin VI of the power chip U2 is connected to the output terminal Vi of the operational amplifier U1, pin VEE of the power chip U2 is connected to the common terminal of the capacitor C6 and the capacitor C3, and pin VDD of the power chip U2 is connected to the common terminal of the capacitor C6 and the capacitor C2; pin VA of the power chip U2 is connected to pin 1 of the transformer T1 through the capacitors C13, C14 and C15 connected in parallel in pairs, pin 3 of the transformer T1 is used to output phase A of the three-phase AC voltage, and pin VB of the power chip U2 is connected in parallel in pairs. The capacitor C19, the capacitor C20, and the capacitor C21 are then connected to the pin 1 of the transformer T3, and the pin 3 of the transformer T3 is used to output the B phase of the three-phase AC voltage. The pin VC of the power chip U2 is connected to the pin 1 of the transformer T2 through the capacitors C16, the capacitor C17, and the capacitor C18 connected in parallel in pairs, and the pin 3 of the transformer T2 is used to output the C phase of the three-phase AC voltage. The pin 2 of the transformer T1, the pin 2 of the transformer T2, and the pin 2 of the transformer T3 are all connected to the common end of the capacitor C6 and the capacitor C3.

[0010] Furthermore, based on the above solution, a choke coil and / or a filter capacitor is also connected in series to the input end of the DC voltage divider circuit.

[0011] In a second aspect, the present application provides a static variable power supply device, which includes a housing and a circuit board having any one of the static variable power supply circuits in the first aspect, wherein the circuit board is disposed in the housing.

[0012] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0013] The present application provides a static power supply circuit, which divides the connected DC voltage into a positive and a negative DC voltage through a DC voltage divider circuit. The positive and negative DC voltages will provide the required electrical energy for the sine wave output circuit and the three-phase voltage output circuit. After the sine wave output circuit is connected to a positive and negative DC voltage, it generates a stable and continuous sine wave signal through the principle of a sine wave generator, providing a stable and reliable sine wave signal source for the three-phase voltage output circuit. Then, the three-phase voltage output circuit uses the positive and negative DC voltages generated by the DC voltage divider circuit and the sine wave signal provided by the sine wave output circuit to output the three-phase voltage through internal operational amplification, power amplification, voltage feedback adjustment and network phase shifting, and then the rear stage can use capacitors and transformers for rectification, filtering and isolation to induce the output of high-quality static variable AC voltage. In other words, by optimizing the topological structure between the DC voltage divider circuit, the sine wave output circuit and the three-phase voltage output circuit, a low-noise, fast-response static variable voltage can be provided, thereby meeting the application scenario requiring high-quality static variable voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 This is a circuit structure block diagram of an embodiment of a static variable power supply circuit of the present application;

[0016] Figure 2 This is a structural schematic diagram of a DC voltage divider circuit of an embodiment of a static variable power supply circuit of the present application;

[0017] Figure 3 This is a structural schematic diagram of a sine wave output circuit of an embodiment of a static variable power supply circuit of the present application;

[0018] Figure 4 This is a structural schematic diagram of a three-phase voltage output circuit of an embodiment of a static variable power supply circuit of the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0021] Example:

[0022] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0023] Please refer to Figure 1 , the static variable power supply circuit includes a DC voltage divider circuit, a sine wave output circuit and a three-phase voltage output circuit, and the sine wave output circuit includes a positive feedback circuit and an amplifier circuit. The input end of the DC voltage divider circuit is used to be connected to an external DC voltage to output a positive and a negative DC voltage at the output end of the DC voltage divider circuit, the input end of the amplifier circuit is connected to the output end of the DC voltage divider circuit to output a sinusoidal signal at the output end of the amplifier circuit, the input end of the positive feedback circuit is connected to the output end of the amplifier circuit, and the output end of the positive feedback circuit is connected to the input end of the amplifier circuit. The power input end of the three-phase voltage output circuit is connected to the output end of the DC voltage divider circuit, the signal input end of the three-phase voltage output circuit is connected to the output end of the sine wave output circuit, and the output end of the three-phase voltage output circuit is used to output a three-phase AC voltage.

[0024] The working principle of a conventional static variable power supply is mainly to convert direct current into alternating current through rectification, filtering, inversion and other circuits, and to accurately control the output voltage, frequency, etc. through a control circuit. In the above embodiment, the DC voltage connected is divided into a positive and a negative DC voltage by a DC voltage divider circuit (for example, if the connected DC is +28V, it can be divided into a DC of +14V and a DC of -14V). The positive and negative DC voltages will provide the required electrical energy for the sine wave output circuit and the three-phase voltage output circuit. After the sine wave output circuit is connected to a positive and negative DC voltage, a stable and continuous sinusoidal wave signal is generated through the principle of a sine wave generator, providing a stable and reliable sinusoidal wave signal source for the three-phase voltage output circuit. Next, the three-phase voltage output circuit uses the positive and negative DC voltages generated by the DC voltage divider circuit and the sine wave signal provided by the sine wave output circuit to output the three-phase voltage through internal operational amplification, power amplification, voltage feedback adjustment and network phase shifting. Then, the subsequent stage can use capacitors and transformers for rectification, filtering and isolation to sense and output high-quality static AC voltage. Among them, the three-phase voltage is controlled by three sine wave signals with a phase difference of 120 degrees. The sine wave signal is used as a control signal, and by changing its amplitude, frequency or phase, the three-phase voltage output by the three-phase voltage output circuit can be precisely controlled.

[0025] It should be noted that the sine wave signal is formed by adding positive feedback to the amplifier circuit, so the positive feedback network and the amplifier circuit are two indispensable components of the sine wave output circuit. The amplifier circuit is used to amplify the input signal, and the positive feedback network feeds the amplified signal back to the input end to form a closed network. Furthermore, the sine wave output circuit can also include an optional network for selecting a specific frequency so that the circuit can output a stable sine wave signal. Furthermore, the sine wave output circuit can also include an amplitude stabilization circuit for controlling the amplitude of the output signal to prevent nonlinear distortion caused by excessive positive feedback.

[0026] In some embodiments of the present application, a choke coil and / or a filter capacitor is further connected in series to the input end of the DC voltage divider circuit to achieve electromagnetic interference resistance.

[0027] Among them, the choke also plays a role of current limiting by limiting the size of the input current, thereby stabilizing the voltage of the static variable power supply circuit. In addition, when the load connected to the three-phase voltage output circuit changes, the ripple of the output voltage can be effectively eliminated, ensuring the stability and reliability of the static variable power supply circuit, helping to protect the load circuit and prevent damage to electronic equipment due to voltage fluctuations. The filter capacitor can also play a role in smoothing the DC voltage signal. Since the DC voltage connected to the DC voltage divider circuit may be a DC voltage obtained by rectification, the DC voltage obtained after rectification will still have AC components and noise signals, which may affect the stability of the DC voltage connected to the DC voltage divider circuit and reduce the performance and reliability of the static variable power supply circuit. By connecting the filter capacitor in series, these clutter and AC components can be filtered out, making the DC voltage connected to the DC voltage divider circuit smoother, thereby improving the quality and stability of the static variable power supply circuit.

[0028] Please refer to Figure 2 In some embodiments of the present application, the DC voltage divider circuit includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, resistor R1, resistor R2, resistor R3, resistor R4 and yoke coil A14. The capacitor C2 and the capacitor C3 are connected in series and then connected in parallel with the capacitor C1. The common end of the capacitor C2 and the capacitor C1 is connected to the power input through the yoke coil A14. The resistor R1, the capacitor C4 and the resistor R3 are all connected in parallel with the capacitor C2. The resistor R2, the capacitor C5 and the resistor R4 are all connected in parallel with the capacitor C3. The common end of the capacitor C3 and the capacitor C1 is grounded through the yoke coil A14. The common end of the capacitor C4 and the capacitor C5 is grounded. The capacitor C6 is connected in parallel with the capacitor C1. The common end of the capacitor C6 and the capacitor C2 is used to output a positive DC voltage, and the common end of the capacitor C6 and the capacitor C3 is used to output a negative DC voltage.

[0029] In the above embodiment, the external DC voltage connected will be distributed to different resistors through the voltage division ratio of resistors R1, R2, R3 and R4, and then the external DC voltage connected can be divided into two parts by adjusting the resistance value and the voltage division ratio of the resistors. The capacitors C1, C2, C3, C4, C5 and C6 play the role of isolating the DC component, that is, they are used to isolate the positive DC after voltage division ( Figure 2 +14V) and negative DC ( Figure 2Specifically, when the external DC voltage (usually +28V DC voltage) is input, the resistor divider network (a network composed of resistors R1, R2, R3 and R4) divides the external DC voltage into two parts ( Figure 2 One part passes through the positive DC output branch, and the other part passes through the negative DC output branch.

[0030] Please refer to Figure 3 In some embodiments of the present application, the sinusoidal wave output circuit includes a voltage regulator diode V1, an operational amplifier U1, a variable resistor R12, a variable resistor R9, a variable resistor R16, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R10, a resistor R11, a resistor R13, a resistor R15, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11 and a capacitor C12. The positive electrode of the power supply of the operational amplifier U1 is connected to the common end of the capacitor C6 and the capacitor C2 through the resistor R5, the capacitor C7 and the capacitor C8 connected in parallel in pairs, and the negative electrode of the power supply of the operational amplifier U1 is connected to the common end of the capacitor C6 and the capacitor C3 through the resistor R6, the capacitor C9 and the capacitor C10 connected in parallel in pairs; the non-inverting input end of the operational amplifier U1 is grounded through the capacitor C12, and the non-inverting input end of the operational amplifier U1 is grounded through the resistor R8 and the variable resistor R9 connected in series in sequence, and the non-inverting input end of the operational amplifier U1 is also connected in series in sequence through the capacitors C11, the resistor R15, and the variable resistor R16 are connected to the output end of the operational amplifier U1; the inverting input end of the operational amplifier U1 is grounded through the resistor R10 and the resistor R7 connected in series in sequence, and the inverting input end of the operational amplifier U1 is also connected to the common end of the resistor R7 and the resistor R10 through the resistor R13, the variable resistor R12, the resistor R11 and the voltage-stabilizing diode V1 connected in series in sequence, and the common end of the resistor R13 and the variable resistor R12 is connected to the output end of the operational amplifier U1, and the output end of the operational amplifier U1 is used to output the sinusoidal signal Vi.

[0031] In the above embodiment, the RC series-parallel network composed of resistor R15, resistor R16, resistor R8, resistor R9, capacitor C11 and capacitor C12 outputs positive feedback to the non-inverting input terminal of the operational amplifier U1, and resistor R7, resistor R10 and resistor R13 output negative feedback to the inverting input terminal of the operational amplifier U1. The oscillation behavior of the circuit depends on the alternating operation of positive and negative feedback, and the operating frequency ff depends on the resistance and capacitance of resistor R15, resistor R16, resistor R8, resistor R9, capacitor C11 and capacitor C8. The calculation formula of frequency f is: Due to the deviation of the calibration value in the device processing technology, in order to make the circuit output 1000Hz voltage, the capacitor C8 and capacitor C11 are 6.5nF, the resistors R8 and R15 are 31kΩ, and the resistors R9 and R16 are 599Ω~2.9kΩ adjustable. After debugging, select fixed resistance resistors for installation. According to the virtual short working principle of the operational amplifier, the voltage at the in-phase terminal is equal to the voltage at the reverse terminal. When the voltage zener diode V1, resistor R11, and resistor R12 are not involved in the work, the calculation formula for the amplification factor A of the circuit is:

[0032] Please refer to Figure 4 In some embodiments of the present application, the three-phase voltage output circuit includes a power chip U2 of JLDY-1000 model, a transformer T1, a transformer T2, a transformer T3, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C19, a capacitor C20 and a capacitor C21. Pin VI of the power chip U2 is connected to the output terminal Vi of the operational amplifier U1, pin VEE of the power chip U2 is connected to the common terminal of the capacitor C6 and the capacitor C3, and pin VDD of the power chip U2 is connected to the common terminal of the capacitor C6 and the capacitor C2; pin VA of the power chip U2 is connected to pin 1 of the transformer T1 through the capacitors C13, C14 and C15 connected in parallel in pairs, pin 3 of the transformer T1 is used to output phase A of the three-phase AC voltage, and pin VB of the power chip U2 is connected in parallel in pairs. The capacitor C19, the capacitor C20, and the capacitor C21 are then connected to the pin 1 of the transformer T3, and the pin 3 of the transformer T3 is used to output the B phase of the three-phase AC voltage. The pin VC of the power chip U2 is connected to the pin 1 of the transformer T2 through the capacitors C16, the capacitor C17, and the capacitor C18 connected in parallel in pairs, and the pin 3 of the transformer T2 is used to output the C phase of the three-phase AC voltage. The pin 2 of the transformer T1, the pin 2 of the transformer T2, and the pin 2 of the transformer T3 are all connected to the common end of the capacitor C6 and the capacitor C3.

[0033] In the above embodiment, the three-phase voltage output circuit uses a +14V DC voltage and a -14V DC voltage provided by a DC voltage divider circuit, and a Vi sine wave provided by a sine wave output circuit, and outputs Va, Vb, and Vc voltages after operational amplification, power amplification, voltage feedback adjustment, and network phase shifting inside the power chip U2. The back stage uses capacitors and transformers for rectification, filtering, and isolation, and the inductive output period is a static variable power supply AC voltage of 36V1000Hz.

[0034] The embodiment of the present application also provides a static variable power supply device, which includes a housing and a circuit board provided with the above-mentioned static variable power supply circuit, and the circuit board is arranged in the housing. By packaging the circuit board provided with the static variable power supply circuit into the housing, a static variable power supply device is made, which can be convenient and quick for users to use.

[0035] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A static variable power supply circuit, characterized in that: It includes a DC voltage dividing circuit, a sine wave output circuit and a three-phase voltage output circuit, wherein the sine wave output circuit includes a positive feedback circuit and an amplifier circuit; The input end of the DC voltage divider circuit is used to be connected to an external DC voltage so as to output a positive and a negative DC voltage at the output end of the DC voltage divider circuit, the input end of the amplifier circuit is connected to the output end of the DC voltage divider circuit so as to output a sinusoidal signal at the output end of the amplifier circuit, the input end of the positive feedback circuit is connected to the output end of the amplifier circuit, and the output end of the positive feedback circuit is connected to the input end of the amplifier circuit; The power input end of the three-phase voltage output circuit is connected to the output end of the DC voltage divider circuit, the signal input end of the three-phase voltage output circuit is connected to the output end of the sine wave output circuit, and the output end of the three-phase voltage output circuit is used to output a three-phase AC voltage.

2. A static variable power supply circuit according to claim 1, characterized in that: The DC voltage divider circuit includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, resistor R1, resistor R2, resistor R3, resistor R4 and yoke coil A14; The capacitor C2 and the capacitor C3 are connected in series and then connected in parallel with the capacitor C1. The common end of the capacitor C2 and the capacitor C1 is connected to the power input through the yoke coil A14. The resistor R1, the capacitor C4 and the resistor R3 are all connected in parallel with the capacitor C2. The resistor R2, the capacitor C5 and the resistor R4 are all connected in parallel with the capacitor C3. The common end of the capacitor C3 and the capacitor C1 is grounded through the yoke coil A14. The common end of the capacitor C4 and the capacitor C5 is grounded. The capacitor C6 is connected in parallel with the capacitor C1. The common end of the capacitor C6 and the capacitor C2 is used to output a positive DC voltage, and the common end of the capacitor C6 and the capacitor C3 is used to output a negative DC voltage.

3. A static variable power supply circuit according to claim 2, characterized in that: The sine wave output circuit includes a voltage stabilizing diode V1, an operational amplifier U1, a variable resistor R12, a variable resistor R9, a variable resistor R16, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R10, a resistor R11, a resistor R13, a resistor R15, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11 and a capacitor C12; The positive electrode of the power supply of the operational amplifier U1 is connected to the common end of the capacitor C6 and the capacitor C2 through the resistor R5, the capacitor C7 and the capacitor C8 connected in parallel in pairs, and the negative electrode of the power supply of the operational amplifier U1 is connected to the common end of the capacitor C6 and the capacitor C3 through the resistor R6, the capacitor C9 and the capacitor C10 connected in parallel in pairs; the non-inverting input end of the operational amplifier U1 is grounded through the capacitor C12, and the non-inverting input end of the operational amplifier U1 is grounded through the resistor R8 and the variable resistor R9 connected in series in sequence, and the non-inverting input end of the operational amplifier U1 is also connected in series in sequence through the capacitors C11, the resistor R15, and the variable resistor R16 are connected to the output end of the operational amplifier U1; the inverting input end of the operational amplifier U1 is grounded through the resistor R10 and the resistor R7 connected in series in sequence, and the inverting input end of the operational amplifier U1 is also connected to the common end of the resistor R7 and the resistor R10 through the resistor R13, the variable resistor R12, the resistor R11 and the voltage-stabilizing diode V1 connected in series in sequence, and the common end of the resistor R13 and the variable resistor R12 is connected to the output end of the operational amplifier U1, and the output end of the operational amplifier U1 is used to output the sinusoidal signal Vi.

4. A static variable power supply circuit according to claim 3, characterized in that: The three-phase voltage output circuit includes a power chip U2 of JLDY-1000 model, a transformer T1, a transformer T2, a transformer T3, a capacitor C13, a capacitor C14, a capacitor C15, a capacitor C16, a capacitor C17, a capacitor C18, a capacitor C19, a capacitor C20 and a capacitor C21; The pin VI of the power chip U2 is connected to the output terminal Vi of the operational amplifier U1, the pin VEE of the power chip U2 is connected to the common end of the capacitor C6 and the capacitor C3, and the pin VDD of the power chip U2 is connected to the common end of the capacitor C6 and the capacitor C2; the pin VA of the power chip U2 is connected to the pin 1 of the transformer T1 through the capacitors C13, C14, and C15 connected in parallel in pairs, the pin 3 of the transformer T1 is used to output the A phase of the three-phase AC voltage, and the pin VB of the power chip U2 is connected in parallel in pairs. The capacitor C19, the capacitor C20, and the capacitor C21 are then connected to the pin 1 of the transformer T3, and the pin 3 of the transformer T3 is used to output the B phase of the three-phase AC voltage. The pin VC of the power chip U2 is connected to the pin 1 of the transformer T2 through the capacitors C16, the capacitor C17, and the capacitor C18 connected in parallel in pairs, and the pin 3 of the transformer T2 is used to output the C phase of the three-phase AC voltage. The pin 2 of the transformer T1, the pin 2 of the transformer T2, and the pin 2 of the transformer T3 are all connected to the common end of the capacitor C6 and the capacitor C3.

5. A static variable power supply circuit according to claim 1, characterized in that: The input end of the DC voltage divider circuit is also connected in series with a choke coil and / or a filter capacitor.

6. A static variable power supply device, characterized in that: It comprises a shell and a circuit board provided with a static variable power supply circuit as claimed in any one of claims 1 to 5, wherein the circuit board is arranged in the shell.

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