Isolation high-precision high-voltage power supply circuit and device

Abstract

The invention provides an isolation high-precision high-voltage power supply circuit and device, the isolation high-precision high-voltage power supply circuit comprises a primary side circuit and a secondary side circuit, the primary side circuit is electrically isolated from the secondary side circuit through an isolation power supply module, and the isolation power supply module converts the voltage of the primary side into the voltage adaptive to the secondary side; the output isolation voltage control module receives a control signal output by the main control unit and converts the control signal into a control voltage adaptive to the high-precision module power supply; the high-precision voltage module is arranged on the secondary side circuit, the power supply end of the high-precision voltage module is connected with the isolated power supply module, the control end receives the control voltage, and adjustable voltage is output within a preset range according to a preset proportion; the output voltage isolation feedback module is arranged across the primary side circuit and the secondary side circuit; and the output voltage isolation feedback module receives the voltage of the high-precision voltage module. Bidirectional isolation closed-loop control is formed, and the precision, safety and reliability of the system are remarkably enhanced.

Description

Technical Field

[0001] The present invention relates to an isolated high-precision high-voltage power supply circuit and device. Background Art

[0002] Existing adjustable high-voltage power supplies typically use unidirectional optocouplers or digital isolators, transmitting only control signals from the low-voltage side to the high-voltage side and relying on a closed-loop, high-precision voltage module for voltage regulation. While this structure provides basic safety isolation, it suffers from common issues such as low isolation link bandwidth, poor linearity, large optocoupler aging drift, and the inability to obtain accurate, real-time output high-voltage information. When a system requires a balance between fast dynamic response, high-voltage output linearity, and high isolation withstand voltage, it often requires the introduction of costly digital isolation ADC / PWM architectures or multi-stage voltage sampling and compensation circuits, resulting in high cost, complex debugging, and limited reliability.

[0003] On the other hand, scenarios such as laboratory instrumentation, mass spectrometry, and electrostatic spraying place higher demands on wide-range high-voltage regulation accuracy and isolation withstand voltage. Using only unidirectional isolation control and high-voltage side voltage sampling requires not only additional common-mode suppression and anti-interference design, but also makes it difficult to return high-resolution feedback signals to the main control unit in real time while maintaining a safe high-voltage distance. This can lead to risks such as output drift, excessive EMI, and measurement and control step loss. Therefore, there is an urgent need for a high-voltage power supply system that combines high isolation, a bidirectional analog closed-loop, high dynamic bandwidth, and low cost to address the compatibility and accuracy limitations of existing technologies. Summary of the Invention

[0004] The present invention provides an isolated high-precision high-voltage power supply circuit and device, which monitors the actual output voltage information and feeds it back to the main control unit, and has the advantages of low cost, wide input voltage range and fast dynamic response.

[0005] The present invention provides an isolated high-precision high-voltage power supply circuit, comprising a primary-side circuit and a secondary-side circuit, including: It includes an isolated power supply module, an output voltage isolation feedback module and a high-precision voltage module; the primary side circuit is electrically isolated from the secondary side circuit by the isolated power supply module, and the isolated power supply module converts the primary side voltage into a voltage that is suitable for the secondary side; The output isolation voltage control module is arranged across the primary side circuit and the secondary side circuit; the output isolation voltage control module receives the control signal output by the main control unit and converts the control signal into a control voltage adapted to the high-precision module power supply; A high-precision voltage module is provided in the secondary side circuit, the power supply end of the high-precision voltage module is connected to the isolated power supply module, the control end receives the control voltage, and outputs an adjustable voltage within a preset range according to a preset ratio; The output voltage isolation feedback module is arranged across the primary side circuit and the secondary side circuit; the output voltage isolation feedback module receives the voltage of the high-precision voltage module, and obtains a feedback signal after buffering, voltage reduction, second isolation amplification and linear amplification, and the feedback signal is used to transmit to the main control unit; The isolated power supply module provides power isolation, and the isolated voltage control module and the output voltage isolation feedback module provide signal isolation, forming a bidirectional isolated closed-loop control.

[0006] In some embodiments, the isolation level of the isolated high-precision high-voltage power supply circuit is determined by the minimum isolation level among the isolated power supply module, the output isolation voltage control module, and the output voltage isolation feedback module.

[0007] In some embodiments, the output isolation voltage control module includes a first voltage dividing unit, a filtering unit, a first isolation amplifier, an operational amplifier unit, and a limiting unit; The first voltage dividing unit divides the control signal input from the main control unit to an input range that is adapted to the isolation amplifier; The filtering unit is used to filter out clutter interference in the control signal; The second pin of the first isolation amplifier is connected to the output end of the filtering unit to convert the filtered control signal into a differential signal for output; The operational amplifier unit is connected to the sixth pin and the seventh pin of the first isolation amplifier, converts the differential signal into a single-ended signal, amplifies and outputs a control voltage; The limiting unit includes a diode for limiting the positive peak value and negative voltage of the output voltage to drive the control end of the high-precision voltage module.

[0008] In some embodiments, the output voltage isolation feedback module includes a buffer, a second voltage divider unit, an RC filter unit, a second isolation amplifier, and a linear operational amplifier; The buffer receives the feedback voltage outputted from the feedback terminal of the high-precision voltage module and buffers the high-impedance signal; The second voltage dividing unit divides the feedback voltage to an input range that is adapted to the isolation operational amplifier; The RC filter unit filters out high-frequency noise in the feedback signal; The second isolation amplifier converts the filtered feedback signal into a differential signal output; The linear operational amplifier amplifies the differential signal to a preset multiple and outputs a feedback voltage within a preset range to the main control unit.

[0009] In some embodiments, the high-precision voltage module includes a main body PS4, the power supply end of the main body PS4 is connected to the output end of the isolated power supply module, and the ground end of the main body PS4 is grounded; the feedback end of the main body PS4 is connected to the input end of the buffer of the output voltage isolation feedback module, and the enable end of the main body PS4 is connected to the main control unit to obtain a high-level enable signal; the control end of the main body PS4 is connected to the output end of the limiting unit of the output isolation voltage control module, and controls the output end of the high-precision voltage module PS4 to output the isolated voltage according to the voltage change received from the output end of the limiting unit.

[0010] In some embodiments, the primary-side circuit further includes a first front-stage power supply module and a second front-stage power supply module, wherein the first front-stage power supply module is used to provide ±12V voltage to the primary-side circuit and power the second front-stage power supply module, and the second front-stage power supply module is used to provide +5V power supply; The secondary side circuit further includes a first rear-stage power supply module and a second rear-stage power supply module. The first rear-stage power supply module is used to provide ±12V voltage for the secondary side circuit, and the second rear-stage power supply module is used to provide +5V power supply.

[0011] In some embodiments, a main control unit interface module is further included, which is connected to the main control unit, receives a control signal from the main control unit, and outputs a feedback signal processed by the output voltage isolation feedback module to the main control unit.

[0012] In some embodiments, the isolation voltage value of the isolated power module determines the isolation level of the isolated high-precision high-voltage power circuit.

[0013] In some embodiments, the first voltage divider unit includes a resistor R9 and a resistor R14, and the control end output by the main control unit interface module is connected to the resistor R9 and the resistor R14; the common end of the resistor R9 and the resistor R14 is connected to the second pin of the first isolation amplifier; The filter unit includes a capacitor C30, a resistor R10 and a capacitor C31. The capacitor C30, the resistor R10 and the capacitor C31 form a π-type filter unit to filter out interference of the control signal; The third pin, the fourth pin, and the fifth pin of the first isolation amplifier U3 are grounded respectively, and the sixth pin and the seventh pin of the first isolation amplifier are connected to the operational amplifier unit; The operational amplifier unit includes an operational amplifier U4A, the input end of the operational amplifier U4A is connected to the sixth pin and the seventh pin of the first isolation amplifier U3, and the output end of the operational amplifier U4A is connected to the limiter unit via the resistor R12 and the capacitor C32; The amplitude limiting unit includes a diode D2 and a diode D3 , and the diode D2 and the diode D3 are connected in parallel between the output end of the resistor R12 and the capacitor C32 and the ground.

[0014] The present invention also provides a device comprising any of the above-described isolated high-precision high-voltage power supply circuits.

[0015] This invention provides an isolated high-precision high-voltage power supply circuit and device. This device utilizes an isolated power module to electrically isolate the primary and secondary sides, blocking high-voltage interference and ensuring the safety of the main control. An output isolated voltage control module precisely converts control signals, improving high-voltage regulation accuracy. A high-precision voltage module supports adjustable output within a preset range, adapting to multiple scenarios. An output voltage isolation feedback module establishes a closed-loop link, dynamically corrects deviations, and stabilizes output. This invention establishes bidirectional isolated closed-loop control, significantly enhancing the system's accuracy, safety, and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural schematic diagram of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 2 A circuit schematic diagram of an isolated power supply module for isolating a high-precision high-voltage power supply circuit provided by the present invention; Figure 3 This is a circuit schematic diagram of an output isolation voltage control module of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 4 A circuit schematic diagram of a high-precision voltage module of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 5 This is a circuit schematic diagram of an output voltage isolation feedback module of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 6 This is a circuit schematic diagram of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 7 This is a circuit schematic diagram of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 8 This is a circuit schematic diagram of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 9 This is a circuit schematic diagram of an isolated high-precision high-voltage power supply circuit provided by the present invention; Figure 10 This is a circuit schematic diagram of an isolated high-precision high-voltage power supply circuit provided by the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below with reference to the accompanying drawings.

[0018] The present application provides an isolated high-precision high-voltage power supply circuit that monitors the actual output voltage information and feeds it back to the main control unit, which has the advantages of low cost, wide input voltage range and fast dynamic response.

[0019] like Figure 1 As shown, this circuit includes a primary side circuit and a secondary side circuit, including an isolated power supply module, an output voltage isolation feedback module and a high-precision voltage module; the primary side circuit is electrically isolated from the secondary side circuit by the isolated power supply module, and the isolated power supply module converts the primary side voltage into a voltage that is compatible with the secondary side; The output isolation voltage control module is arranged across the primary side circuit and the secondary side circuit; the output isolation voltage control module receives the control signal output by the main control unit and converts the control signal into a control voltage adapted to the high-precision module power supply; A high-precision voltage module is provided in the secondary side circuit, the power supply end of the high-precision voltage module is connected to the isolated power supply module, the control end receives the control voltage, and outputs an adjustable voltage within a preset range according to a preset ratio; The output voltage isolation feedback module is arranged across the primary side circuit and the secondary side circuit; the output voltage isolation feedback module receives the voltage of the high-precision voltage module, and obtains a feedback signal after buffering, voltage reduction, second isolation amplification and linear amplification, and the feedback signal is used to transmit to the main control unit; The isolated power supply module provides power isolation, and the isolated voltage control module and the output voltage isolation feedback module provide signal isolation, forming a bidirectional isolated closed-loop control.

[0020] Specifically, such as Figure 2 As shown, the isolated power supply module in the primary circuit provides operating voltage and current for the isolated post-stages PS3 and PS4. The isolated power supply module includes PS1, an input filter unit, and a transformer. Capacitors C44 and C5 in the input filter unit connect to the positive voltage (+24V) and ground (GND), filtering the input DC voltage and removing high-frequency noise and interference signals, ensuring a smoother and purer voltage input to the isolated power supply module. Capacitor C5 is a large 220uF / 35V capacitor used to filter low-frequency interference, while capacitor C44 is a small 1uF / 35V capacitor used primarily to filter high-frequency interference. Together, these two components effectively improve the quality of the input voltage.

[0021] The isolated power supply module includes an isolated power supply module body PS1. In this application, URB2424LD-20WR3 and URH2424P-6WR3 are used. Its isolation voltage directly affects the isolation voltage value of this circuit. The input is DC24V±10%, and the output is DC24V±1%. It provides operating voltage and current for the first and second post-stage power supply modules. The filter capacitors C6 and C7 at the output end of the isolated power supply module are both 220uF / 35V. Capacitor C6 is connected in parallel with the secondary winding of the transformer, and capacitor C7 is connected to the output positive voltage +VCC and ground. This further filters the output DC voltage, reduces the ripple factor, and improves the output voltage quality. Transformer T1 is connected to the output end of the isolated power supply module body PS1 to achieve electrical isolation and voltage conversion. The transformer primary winding is connected to the isolated power supply module body PS1, and the secondary winding is connected to the output filter capacitor. This filters the high-frequency ripple in the output voltage, further improving the output voltage stability and smoothness.

[0022] The isolation voltage of the isolated power supply module determines the isolation level of the isolated high-precision high-voltage power supply circuit. By selecting isolated power supply modules with different isolation levels, you can achieve different isolation levels within 5 kV. Select the appropriate isolation level based on the actual application scenario. Op amps with higher isolation levels will improve isolation. Using isolated power supply modules with different output voltages allows you to achieve a wider range of effective output voltages for the isolated power supply.

[0023] The output isolation voltage control module is set across the primary side circuit and the secondary side circuit, and can control the output voltage within a preset range and upload the output voltage information. The output isolation control module includes a first voltage divider unit, a filter unit, a first isolation amplifier, an operational amplifier unit, and a limiter unit; the first voltage divider unit divides the control signal input by the main control unit to an input range that is adapted to the isolation amplifier; the filter unit is used to filter out clutter interference in the control signal; the second pin of the first isolation amplifier is connected to the output end of the filter circuit, converting the filtered control signal into a differential signal output; the operational amplifier unit is connected to the sixth and seventh pins of the first isolation amplifier, converting the differential signal into a single-ended signal, amplifying and outputting the control voltage; the limiter unit includes a diode that limits the positive peak and negative voltage of the output voltage to drive the control end of the high-precision voltage module.

[0024] Specifically, such as Figure 3As shown, the first voltage divider unit includes a resistor R9 and a resistor R14, and the control end output by the main control unit interface module is connected to the resistor R9 and the resistor R14; the common end of the resistor R9 and the resistor R14 is connected to the second pin of the first isolation amplifier; the filtering unit includes a capacitor C30, a resistor R10 and a capacitor C31, and the capacitor C30, the resistor R10 and the capacitor C31 constitute a π-type filtering unit to filter out interference with the control signal; the third pin, the fourth pin and the fifth pin of the first isolation amplifier U3 are grounded respectively, and the sixth pin and the seventh pin of the first isolation amplifier U3 are connected to the operational amplifier Unit; the third, fourth, and fifth pins of the first isolation amplifier U3 are grounded, respectively, and the sixth and seventh pins of the first isolation amplifier are connected to the op amp unit; the op amp unit includes an op amp U4A, the input of which is connected to the sixth and seventh pins of the first isolation amplifier U3, and the output of which is connected to a limiter unit via a resistor R12 and a capacitor C32; the limiter unit includes a diode D2 and a diode D3, which are connected in parallel between the output of resistor R12 and capacitor C32 and ground. The op amp U4A, together with resistors R11, R12, R13, R15, and R6, and capacitors C33 and C26, forms an amplifier circuit with an amplification factor of 3.333. The limiting unit includes a diode D2 and a diode D3, which are connected in parallel between the output end of the resistor R12 and the capacitor C32 and the ground, and play a clamping protection role in the output voltage to prevent the output voltage from being too high or too low and damaging subsequent connected devices.

[0025] In the present application, the input voltage first passes through a filter unit composed of a capacitor C30 and a resistor R14 for preliminary noise filtering, and then undergoes corresponding voltage adjustment and other processing through the first voltage divider unit to provide suitable input conditions for subsequent isolation chips and other circuits. The first isolation amplifier electrically isolates the input signal, and transmits the electrical signal on the input side to the output side through magnetic coupling or optical coupling. At the same time, it electrically isolates the input and output, which can effectively prevent electrical interference and noise on the input side from affecting the circuit on the output side, thereby improving the anti-interference ability and safety of the entire module. The gain of the first isolation amplifier can be determined according to the actual scenario of the application of this circuit and is not limited in this application. In the present application, the first isolation amplifier uses a 1:1 fixed gain to isolate and amplify the control signal.

[0026] The isolated signal is input to the op amp unit. Based on the operational amplifier's virtual short and open characteristics and the settings of the external resistors, the op amp amplifies the input signal by a factor of 3.333. The amplified signal is clamped at the output by diodes D2 and D3 to prevent the output voltage from exceeding a certain range and potentially damaging subsequent equipment. Furthermore, capacitors C32 and C34 further filter the output voltage, making the final output voltage more stable and smooth, meeting the voltage requirements of practical applications.

[0027] like Figure 4 As shown, the high-precision voltage module includes a main body PS4, the power supply end of the main body PS4 is connected to the output end of the isolated power supply module, and the ground end of the main body PS4 is grounded; the feedback end of the main body PS4 is connected to the input end of the buffer of the output voltage isolation feedback module, and the enable end of the main body PS4 is connected to the main control unit to obtain a high-level enable signal; the control end of the main body PS4 is connected to the output end of the limiting unit of the output isolation voltage control module, and controls the output end of the high-precision voltage module PS4 to output the isolated voltage according to the voltage change received from the output end of the limiting unit.

[0028] The output voltage of the high-precision voltage module is controlled by pin 8 of the PS4, also known as the control terminal. When the voltage at pin 8 varies between 0 and 5V, a preset high voltage is output between pins 1 and 2, corresponding to the output terminals. Pin 6 is the feedback terminal, which monitors the actual output voltage. The actual output voltage is fed back in a 0-5V range, processed by the output voltage isolation feedback module, and then transmitted to the main control unit. Pin 3, the power supply terminal, is the +24V power input. Pins 4 and 5 are ground terminals. Pin 7 is the PS4 module enable terminal, which is turned on when the voltage is high. Pin 9 is the internal reference source and is left vacant in this application.

[0029] The isolated power supply module provides power to the main PS4 module. When power is applied, the PS4 module's internal circuitry initializes, and its internal reference voltages, control logic, and other components begin operating. The main control unit provides a high-level enable signal to the main PS4's enable terminal, activating the main PS4. Simultaneously, the output isolation voltage control module's limiter unit outputs a voltage change signal to the PS4 module's control terminal. Based on this voltage change signal, the main PS4 adjusts its output voltage using its internal voltage regulation circuitry. After internal regulation and control within the main PS4, the output terminal outputs the corresponding voltage. This voltage is then filtered to smooth the voltage, then isolated and converted to step-up or step-down voltage by transformer T2. The isolated voltage is then output at the transformer's output terminal, supplying subsequent circuits requiring high voltage.

[0030] like Figure 5As shown, the output voltage isolation feedback module is arranged across the primary side circuit and the secondary side circuit, including a buffer, a second voltage divider unit, an RC filter unit, a second isolation amplifier, and a linear operational amplifier; the buffer receives the feedback voltage output by the feedback end of the high-precision voltage module and buffers the high-impedance signal; the second voltage divider unit divides the feedback voltage to an input range that is adapted to the isolation operational amplifier; the RC filter unit filters out high-frequency noise in the feedback signal; the second isolation amplifier converts the filtered feedback signal into a differential signal output; the linear operational amplifier amplifies the differential signal to a preset multiple and outputs a feedback voltage within a preset range to the main control unit.

[0031] Buffer U4B receives the feedback voltage output from the feedback terminal of the high-precision voltage module. Buffers typically have high input impedance and low output impedance, effectively buffering high-impedance signals to prevent signal distortion or attenuation due to load effects during transmission, ensuring that subsequent circuits receive a relatively stable and accurate feedback voltage signal. The second voltage divider unit uses resistors to divide the received feedback voltage by a certain ratio, reducing its amplitude to a value suitable for the input range of the isolation op amp, ensuring that the isolation op amp can process the signal normally. The RC filter circuit, consisting of resistor R20 and capacitor C40, filters out high-frequency noise in the feedback signal; the second isolation amplifier U5 converts the filtered signal into a differential signal output with a fixed gain of 1:1; the linear operational amplifier U6A amplifies the differential signal by 2.4 times and outputs a feedback voltage of 0 to 6V to the main control unit.

[0032] The isolation level of the isolated high-precision high-voltage power supply circuit is determined by the minimum isolation level among the isolated power supply module, the output isolated voltage control module, and the output voltage isolated feedback module. In the high-voltage power supply system, the core goal of the isolation design is to block the electrical connection between the high-voltage side and the low-voltage side through an insulation barrier to prevent high-voltage interference or dangerous voltage from being transmitted to the low-voltage control end. This circuit includes three isolation paths: the isolated power supply module realizes power supply isolation and establishes an insulation barrier between the high-voltage side power supply and the low-voltage side power supply; the output isolated voltage control module realizes the isolated transmission of the control signal; and the output isolated voltage feedback module completes the isolated transmission of the high-voltage side feedback signal and the low-voltage main control unit. The isolation capability of each module is determined by parameters such as the withstand voltage strength, electrical clearance and creepage distance of its internal insulation material.

[0033] Because the overall voltage withstand capability of an electrical isolation system is limited by its weakest insulation link, when interference voltage appears on the high-voltage side, the module with the lowest isolation capability will break down first, causing isolation failure. Therefore, the isolation level of the entire circuit is determined by the module with the weakest isolation capability among the three isolation paths. For example, if the isolation level of the isolated power module is 5kV, the output isolation voltage control module is 3kV, and the output voltage isolation feedback module is 4kV, the overall isolation level is determined by the 3kV of the control module. If the interference on the high-voltage side exceeds 3kV, the insulation barrier of the control module will be destroyed, and the high-voltage interference will be directly transmitted to the low-voltage control end.

[0034] By taking the minimum isolation level among the three, the circuit's maximum safe isolation voltage can be precisely defined, avoiding safety hazards caused by insufficient isolation capability of a particular module. At the same time, the isolation level of each module can be flexibly configured according to actual application requirements. If the system only requires 3kV isolation capability, it is sufficient to ensure that at least one module has an isolation level of 3kV; the remaining modules can use isolation components of a lower or equivalent level. Furthermore, when the isolation capabilities of each isolation path converge, the anti-interference performance is synchronously matched, effectively avoiding signal distortion or system loss of control due to insulation failure in a particular path, ensuring the accuracy of high-voltage output and the reliability of control.

[0035] In order to ensure stable power supply, the primary side circuit also includes a first front-stage power supply module and a second front-stage power supply module. The first front-stage power supply module is used to provide ±12V voltage of the primary side circuit and power supply of the second front-stage power supply module. The second front-stage power supply module is used to provide +5V power supply. Figure 6 、 7 As shown, the first front-stage power supply module includes a main body PS2, which adopts A2412S-2WR3 in this embodiment; the second front-stage power supply module includes a chip U1, which adopts HT7550, and provides operating voltage for the isolation operational amplifier. Figure 8 、 9 As shown, the secondary side circuit also includes a first post-stage power supply module and a second post-stage power supply module. The first post-stage power supply module includes a main body PS3, adopts A2412S-2WR3, and is used to provide ±12V voltage for the secondary side circuit. The second post-stage power supply module does not include chip U2, adopts HT7550, and is used to provide +5V power supply.

[0036] like Figure 10 As shown, the system also includes a main control unit interface module, which is connected to the main control unit, receives control signals from the main control unit, and drives the high-precision voltage module to output a corresponding voltage through the isolated voltage control module. At the same time, it receives feedback signals processed by the output voltage isolation feedback module and transmits them to the main control unit.

[0037] The seventh pin of the main control unit interface module receives the control level, and the initial level range is 0 to 6V. Taking the input 6V as an example, the control signal first enters the output isolation voltage control module, and is divided by resistors R9 and R14 to reduce 6V to 1.5V and transmit it to Figure 3 The signal then passes through a π-type filter circuit consisting of capacitor C30, resistor R10, and capacitor C31, filtering out high-frequency noise and interference, resulting in a purer signal that is transmitted to point b. The signal at point b enters an isolation amplifier with a fixed gain of 1:1. After isolation and amplification, it outputs a differential signal, with the positive-phase signal at terminal c and the negative-phase signal at terminal d.

[0038] The differential signal continues to be transmitted to the op amp U4A, which converts it into a single-ended signal and performs a fixed gain amplification of 3.333 times to adapt the signal amplitude to the control requirements of the high-precision voltage module (0 to 5V). At this time, the signal is transmitted to point e. The signal at point e is then further smoothed by an RC filter circuit composed of resistor R12 and capacitor C32, and then the forward peak is limited by diode D2 and the negative voltage is limited by diode D3. Finally, a stable control signal of 0 to 5V is obtained and transmitted to point f. When the input is 6V, point f outputs a 5V control signal, driving the eighth pin of the high-precision voltage module, so that its output end generates a preset high voltage. The output preset high voltage can be determined in the range of 0 to kilovolts according to the specific application scenario, and is not limited in this application.

[0039] The transmission of the feedback signal starts from the high-precision voltage module. When the high-precision voltage module outputs the preset high voltage, its feedback end synchronously outputs 5V voltage and transmits it to the output voltage isolation feedback module, that is, Figure 5 Point g. Due to the high output impedance of the feedback terminal, the signal at point g is first buffered by buffer U4B to prevent signal attenuation or distortion caused by the high impedance. It is then transmitted to the voltage divider circuit formed by resistors R1 and R2, which reduces the 5V to 2.5V and transmits it to point j. The signal at point j is filtered out of high-frequency noise by an RC filter circuit formed by resistors R20 and capacitor C40. It then passes through diode D1 for overvoltage protection before being transmitted to the second pin of isolation amplifier U5, which is point k. The 2.5V signal at point k is isolated and amplified by U5, outputting a differential signal with the u terminal as the positive phase and the p terminal as the negative phase. This differential signal is then input to linear operational amplifier U6A, amplified 2.4 times, and outputted from its first pin, point M, at a 6V signal. The signal at point M is finally smoothed by an RC filter circuit formed by resistor R19 and capacitor C39 before being fed back to the main control unit via the main control unit interface module, completing the closed-loop control process.

[0040] Based on the same inventive concept, the present application also provides a device including the isolated high-precision high-voltage power supply circuit as described above.

[0041] This invention provides an isolated high-precision high-voltage power supply circuit and device. This device utilizes an isolated power module to electrically isolate the primary and secondary sides, blocking high-voltage interference transmission and ensuring master control safety. An output isolated voltage control module precisely converts control signals, improving high-voltage regulation accuracy. A high-precision voltage module supports preset, adjustable high-voltage outputs, adapting to diverse scenarios. An output voltage isolation feedback module establishes a closed-loop link, dynamically corrects deviations, and stabilizes output. This invention establishes bidirectional isolated closed-loop control, significantly enhancing the system's accuracy, safety, and reliability.

[0042] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. An isolated high-precision high-voltage power supply circuit, comprising a primary side circuit and a secondary side circuit, characterized in that: It includes an isolated power supply module, an output voltage isolation feedback module and a high-precision voltage module; the primary side circuit is electrically isolated from the secondary side circuit by the isolated power supply module, and the isolated power supply module converts the primary side voltage into a voltage that is suitable for the secondary side; The output isolation voltage control module is arranged across the primary side circuit and the secondary side circuit; the output isolation voltage control module receives the control signal output by the main control unit and converts the control signal into a control voltage adapted to the high-precision module power supply; A high-precision voltage module is provided in the secondary side circuit, the power supply end of the high-precision voltage module is connected to the isolated power supply module, the control end receives the control voltage, and outputs an adjustable voltage within a preset range according to a preset ratio; The output voltage isolation feedback module is arranged across the primary side circuit and the secondary side circuit; the output voltage isolation feedback module receives the voltage of the high-precision voltage module, and obtains a feedback signal after buffering, voltage reduction, second isolation amplification and linear amplification, and the feedback signal is used to transmit to the main control unit; The isolated power supply module provides power isolation, and the isolated voltage control module and the output voltage isolation feedback module provide signal isolation, forming a bidirectional isolated closed-loop control.

2. The isolated high-precision high-voltage power supply circuit according to claim 1, characterized in that: The isolation level of the isolated high-precision high-voltage power supply circuit is determined by the minimum isolation level among the isolated power supply module, the output isolation voltage control module, and the output voltage isolation feedback module.

3. The isolated high-precision high-voltage power supply circuit according to claim 1, characterized in that: The output isolation voltage control module includes a first voltage dividing unit, a filtering unit, a first isolation amplifier, an operational amplifier unit, and a limiting unit; The first voltage dividing unit divides the control signal input from the main control unit to an input range that is adapted to the isolation amplifier; The filtering unit is used to filter out clutter interference in the control signal; The second pin of the first isolation amplifier is connected to the output end of the filtering unit to convert the filtered control signal into a differential signal for output; The operational amplifier unit is connected to the sixth pin and the seventh pin of the first isolation amplifier, converts the differential signal into a single-ended signal, amplifies and outputs a control voltage; The limiting unit includes a diode for limiting the positive peak value and negative voltage of the output voltage to drive the control end of the high-precision voltage module.

4. The isolated high-precision high-voltage power supply circuit according to claim 1, wherein: The output voltage isolation feedback module includes a buffer, a second voltage dividing unit, an RC filter unit, a second isolation amplifier, and a linear operational amplifier; The buffer receives the feedback voltage outputted from the feedback terminal of the high-precision voltage module and buffers the high-impedance signal; The second voltage dividing unit divides the feedback voltage to an input range that is adapted to the isolation operational amplifier; The RC filter unit filters out high-frequency noise in the feedback signal; The second isolation amplifier converts the filtered feedback signal into a differential signal output; The linear operational amplifier amplifies the differential signal to a preset multiple and outputs a feedback voltage within a preset range to the main control unit.

5. The isolated high-precision high-voltage power supply circuit according to claim 4, characterized in that: The high-precision voltage module includes a main body PS4, a power supply end of the main body PS4 is connected to the output end of the isolated power supply module, and a ground end of the main body PS4 is grounded; a feedback end of the main body PS4 is connected to the input end of the buffer of the output voltage isolation feedback module, and an enable end of the main body PS4 is connected to the main control unit to obtain a high-level enable signal; The control end of the main body PS4 is connected to the output end of the limiter unit of the output isolation voltage control module, and controls the output end of the high-precision voltage module PS4 to output the isolated voltage according to the voltage change received from the output end of the limiter unit.

6. The isolated high-precision high-voltage power supply circuit according to claim 1, wherein: The primary side circuit further includes a first front-stage power supply module and a second front-stage power supply module, wherein the first front-stage power supply module is used to provide ±12V voltage of the primary side circuit and power supply to the second front-stage power supply module, and the second front-stage power supply module is used to provide +5V power supply; The secondary side circuit further includes a first rear-stage power supply module and a second rear-stage power supply module. The first rear-stage power supply module is used to provide ±12V voltage for the secondary side circuit, and the second rear-stage power supply module is used to provide +5V power supply.

7. The isolated high-precision high-voltage power supply circuit according to claim 1, wherein: It also includes a main control unit interface module, which is connected to the main control unit, receives the control signal of the main control unit, and outputs the feedback signal processed by the output voltage isolation feedback module to the main control unit.

8. The isolated high-precision high-voltage power supply circuit according to claim 1, wherein: The isolation voltage value of the isolated power supply module determines the isolation level of the isolated high-precision high-voltage power supply circuit.

9. The isolated high-precision high-voltage power supply circuit according to claim 3, wherein: The first voltage divider unit includes a resistor R9 and a resistor R14, and the control end output by the main control unit interface module is connected to the resistor R9 and the resistor R14; the common end of the resistor R9 and the resistor R14 is connected to the second pin of the first isolation amplifier; The filter unit includes a capacitor C30, a resistor R10 and a capacitor C31. The capacitor C30, the resistor R10 and the capacitor C31 form a π-type filter unit to filter out interference of the control signal; The third pin, the fourth pin, and the fifth pin of the first isolation amplifier U3 are grounded respectively, and the sixth pin and the seventh pin of the first isolation amplifier are connected to the operational amplifier unit; The operational amplifier unit includes an operational amplifier U4A, the input end of the operational amplifier U4A is connected to the sixth pin and the seventh pin of the first isolation amplifier U3, and the output end of the operational amplifier U4A is connected to the limiter unit via the resistor R12 and the capacitor C32; The amplitude limiting unit includes a diode D2 and a diode D3 , and the diode D2 and the diode D3 are connected in parallel between the output end of the resistor R12 and the capacitor C32 and the ground.

10. A device, characterized in that: The invention comprises an isolated high-precision high-voltage power supply circuit as described in any one of claims 1 to 9.

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