548 results about "Differential amplification" patented technology

The invention relates to the field of biomedical engineering, and discloses an embedded electroencephalogram signal collecting device and system.The device comprises a power management module, a plurality of electrode assemblies, a control module and a storage and communication module; through a control module designed by a system on chip SoC and a multi-electrode assembly in contact with intracranial nerves, the embedded electroencephalogram signal acquisition device which is in multi-level cooperation, supports user-defined sampling parameters and self-adaptive strategies and meets individual requirements of different focus monitoring scenes is constructed. High-precision distributed acquisition and self-adaptive processing of intracranial electroencephalogram signals are realized; a multi-electrode assembly is adopted, each assembly is provided with a plurality of contacts, the limitation of traditional single-point collection is broken through, different nerve areas are covered through the spatially distributed contact layout, and the focus positioning capacity is improved; the acquisition module effectively eliminates power supply ground wire interference and electromagnetic noise by using a differential amplification and common-mode rejection technology, and eliminates power frequency interference by combining band-pass and notch filtering to ensure the quality of an original signal.

This invention relates to a method and system for adaptive reclosing of single-phase AC transmission lines in wind power systems. The invention utilizes single-ended electrical quantity to determine the type of fault. After a fault occurs, a signal acquisition device is used to sample the voltage of the fault phase. The obtained voltage is subjected to short-time Fourier transform to extract the amplitude of the fundamental frequency voltage component, and then processed with differential amplification to construct a fault nature identification criterion. Combined with a sliding time window for fault identification, if it is identified as a permanent fault, the reclosing device is locked out; if it is identified as a transient fault, the fault disappearance time is calculated to determine the reclosing time and output the closing signal. This invention is designed for adaptive reclosing after a circuit breaker trips in wind power AC transmission lines.

The present application relates to the field of solution measurement, in particular to an electrode conductivity sensor conductivity measurement circuit and method, first, the AC excitation generation module generates an amplitude and frequency adjustable AC sine excitation signal under the control of the single-chip microcomputer; then the AC sine excitation signal passes through the precision resistor R0 and the conductivity cell of the electrode sensor to the system ground in turn; then the differential amplification circuit differentially amplifies the voltage between the precision resistor R0 and the electrode sheet of the conductivity cell; the amplified voltage signal is collected by the ADC, and then the voltage data is transmitted to the single-chip microcomputer; finally, the single-chip microcomputer can obtain the conductivity of the solution after the collected voltage data is operated. The present application directly collects the peak and valley voltage values of the AC signal, subtracts to obtain the amplitude of the AC signal, and does not need a rectification filter circuit to detect the amplitude of the AC signal, which can quickly respond to the change of the solution conductivity, eliminates the influence of common-mode interference factors, and simplifies the circuit design.

The utility model relates to an anti-pinch detection circuit and a motor device, the anti-pinch detection circuit comprises a sampling circuit, a differential amplification circuit, a ripple signal conversion circuit, a low pass filter circuit and a controller, the sampling circuit samples a ripple current signal of a vehicle window motor to obtain a corresponding voltage sampling signal, and the voltage sampling signal is sent to the differential amplification circuit; the differential amplification circuit carries out differential amplification on the voltage sampling signal to obtain a voltage amplification signal, the voltage amplification signal is divided into two paths, one path is converted into square wave signals through the ripple signal conversion circuit, the controller determines the position of a car window according to the number of the square wave signals, and the other path is subjected to low-pass filtering through the low-pass filtering circuit to obtain the voltage amplification signal. If the position of the car window is located in the preset anti-pinch area, the controller determines whether the car window is locked or blocked or not according to the amplitude of the low-frequency ripple signal. The anti-pinch detection circuit adopts two-path detection, so that the influence of environment or other factors on the ripple current signal is avoided, further anti-pinch misjudgment is avoided, and the anti-pinch detection accuracy is improved.

The invention relates to a micro-current detection system, which comprises a clamping current sampling unit, a current amplification conditioning unit, an analog-to-digital conversion unit and a controller, and is characterized in that the clamping current sampling unit comprises a plurality of clamping sampling circuits which are sequentially connected in series, and the first clamping sampling circuit and the last clamping sampling circuit are both used for being connected to a detected sensor; the current amplification conditioning unit comprises differential amplification conditioning circuits, the number of the differential amplification conditioning circuits is associated with the number of the clamping sampling circuits, and the differential amplification conditioning circuits are electrically connected to the clamping sampling circuits in a one-to-one correspondence manner; the analog-to-digital conversion unit comprises an analog-to-digital converter, and the analog-to-digital converter is electrically connected to all the differential amplification conditioning circuits; the controller is electrically connected to the analog-to-digital converter. According to the invention, real-time, precise, continuous and dynamic self-adaptive sampling can be carried out on the micro-current through the clamping current sampling unit, and the current amplification gain does not need to be adjusted by frequently switching a sampling resistor. Moreover, the collection noise can be effectively suppressed, and the signal-to-noise ratio is improved.

The invention discloses a gas concentration detection circuit and method based on differential measurement and reference compensation, and the circuit comprises at least one active gas sensitive element, the electrical parameters of which change along with the concentration of a target gas; the sensitivity of the reference gas sensitive element to the target gas is at least lower than that of the active gas sensitive element by a preset percentage threshold value; the active gas sensitive element and the reference gas sensitive element are connected in a differential pair form to form a differential signal generation unit; the differential amplification circuit is used for amplifying the differential signal output by the differential signal generation unit; the output signal of the differential amplification circuit is used for representing the concentration information of the target gas. According to the invention, environmental interference and baseline drift are directly and effectively suppressed from the hardware level, the stability and selectivity of gas concentration measurement are improved, and meanwhile, the holding circuit is simple in structure, low in cost and convenient for large-scale application.

An equalization circuit includes a first equalization circuit and a second equalization circuit. The first equalization circuit, when a swing width decrease signal is activated, adjusts a voltage level of a first signal line in accordance with a second equalization control signal and adjusts a voltage level of a second signal line in accordance with a first equalization control signal to decrease a swing width of a differential amplification signal transmitted over the first signal line and the second signal line. The second equalization circuit, when a swing width increase signal is activated, adjusts the voltage level of the second signal line in accordance with the second equalization control signal and adjusts the voltage level of the first signal line in accordance with the first equalization control signal to increase a swing width of the differential amplification signal.

The invention discloses a signal transmission circuit and system of an electronic mutual inductor and a working method, and belongs to the field of electric power protection and measurement and control. A voltage signal in the same proportion as the primary current signal is output to the voltage-current conversion circuit, and the voltage-current conversion circuit converts the voltage signal into a current signal I1 and outputs the current signal I1 to the constant-current voltage stabilizing circuit; the constant-current voltage stabilizing circuit generates a current signal I2, the current signal I2 supplies power to a pre-stage circuit after voltage stabilization, the current signal I2 and a current signal I1 are superposed to output a current signal I3 to the power supply and signal separation circuit, and the protection measurement and control device extracts the current signal I1 in the current signal I3 and converts the current signal I1 into a voltage signal to be collected. A voltage signal suitable for being collected by an AD chip is output through an active differential amplifier, and power is supplied to a constant-current voltage stabilizing circuit. The problems that signal attenuation is obvious and independent power supply is needed during long-distance transmission of the electronic transformer can be solved.

The invention provides a constant-power driving method of a light source, a light source driver and an air conditioning system, and the constant-power driving method comprises the steps: determining an equivalent voltage corresponding to the power of the current light source based on the working current and working voltage of the current light source obtained in real time; performing differential amplification processing on the equivalent voltage and the expected voltage to generate a constant power modulation instruction of the light source; the expected voltage is a constant voltage simulated according to the rated power of the light source; driving power of the light source is generated based on a constant power modulation instruction of the light source and a feedback adjustment instruction, the driving power is amplified by using a preset power amplification coefficient, the amplified driving power is used for driving the light source to emit light, and the feedback adjustment instruction is generated based on sampling feedback of the driving power of the amplified light source. The constant-power driving of the light source is adopted, so that the service life, the precision and the response speed of the light source are ensured.

The invention discloses a high-precision alternating-current voltage direct-current component detection circuit which comprises a capacitance-resistance voltage division circuit, a differential amplification circuit, a second-order RC filter circuit, a voltage following and lifting circuit and an AD voltage clamping circuit which are arranged in sequence. The invention aims to improve the detection precision of the direct-current voltage in the alternating-current output voltage of the energy storage converter and feed back the detected accurate direct-current voltage amplitude to the CPU to carry out closed-loop control on the system output voltage so as to achieve the purpose of reducing the direct-current component in the alternating-current output voltage of the energy storage converter.

Low noise amplifiers (LNAs) are disclosed herein. In certain embodiments, an LNA includes an input balun configured to convert a single-ended radio frequency (RF) receive signal to a differential RF receive signal, an amplifier chain configured to amplify the differential RF receive signal to generate a differential amplified RF receive signal, and an output balun configured to convert the differential amplified RF receive signal into a single-ended amplified RF receive signal. The LNA's amplifier chain is operable in multiple gain modes, and includes a first differential amplification stage, a second differential amplification stage, and a third differential amplification stage.

The invention provides a gas infrared cross detection system and a detection method, and belongs to the technical field of gas detection. A first detection channel and a second detection channel are arranged in a cavity in parallel at an interval. The first photoacoustic receiving module converts a first photoacoustic signal generated in the first detection channel into a first electric signal. The second photoacoustic receiving module converts a second photoacoustic signal generated in the second detection channel into a second electric signal. The first signal processing module filters and amplifies the first electric signal to obtain a first detection signal. The second signal processing module filters and amplifies the second electric signal to obtain a second detection signal. And the differential amplification module performs differential amplification on the first detection signal and the second detection signal to obtain a concentration detection signal, so that the purpose of differential noise reduction is achieved, and a target signal is enhanced. The main control module determines the concentration of the detected gas according to the concentration detection signal, so that the concentration detection precision is improved, and the problem of low detection accuracy in the traditional technology is solved.

The utility model discloses a background suppression photoelectric sensor realized based on double PD. The background suppression photoelectric sensor comprises an MCU control circuit, an LED drive circuit, an acquisition module, a target object, a differential amplification circuit, a voltage comparison circuit and a self-adaptive output circuit. The acquisition module is used for receiving reflected light signals of a target object and converting the reflected light signals, then the differential amplification circuit amplifies and converts PD signals received by the acquired signals, and then analog quantity signals are converted into pulse signals through the voltage comparison circuit, so that the MCU control circuit can be used for processing logic signals and modulating PWM signals. The LED driving circuit is arranged to drive the LED diode D6 to work; the background suppression photoelectric sensor realized by a photodiode PD1, a photodiode PD2, a differential amplification circuit, a voltage comparison circuit and an MCU control circuit adopts an automatic frequency conversion technology to solve the problem of optical crosstalk among multiple sensors, and is suitable for background suppression photoelectric sensing.

The invention relates to the field of intelligent sensing, and particularly provides a clothes humidity detection device and method. The device comprises a PCB, a first electrode plate, a second electrode plate and a third electrode plate are arranged on the PCB, and planar capacitors are formed between the first electrode plate and the second electrode plate and between the first electrode plate and the third electrode plate. The method comprises the following steps: S1, signal excitation; s2, receiving a signal; s3, amplifying the signal; s4, carrying out signal differential processing; s5, humidity information is output; the method is realized by using the device. The three electrode plates are arranged on the PCB to form two planar capacitors, the electric field distribution is wide, the surface and internal humidity change can be sensed, and the clothes drying degree can be accurately reflected. By means of differential amplification processing of detection signals of the second electrode plate and the third electrode plate, initial capacitance and noise interference are eliminated, and high-accuracy humidity detection is achieved under the complex humidity distribution condition.

The invention relates to a weak current signal detection system and method based on a fluxgate, and the system comprises an excitation module, a range selection module, a power amplification module, a fluxgate magnetic core coil, a sampling resistor, a differential amplification module and a data processing module which are connected in sequence, the magnetic core current reaches saturation current; the range selection module is used for adjusting the gain of the power amplification module; the power amplification module is used for amplifying the excitation signal; the fluxgate magnetic core coil is used for sensing current to be measured; the sampling resistor is used for sampling saturation current of a magnetic core coil of the fluxgate; the differential amplification module is used for amplifying saturation current of a magnetic core coil of the fluxgate; and the data processing module performs time difference calculation on the amplified saturation current through resampling, and outputs a weak current detection result. Compared with the prior art, the hardware cost can be reduced while the measurement precision is improved.

To improve an image quality in a solid-state imaging element that performs differential amplification. A reference-side amplification transistor supplies a reference current corresponding to a predetermined reference potential. A read-side amplification transistor supplies a signal current corresponding to a difference between a potential of a gate and the reference potential from a drain to a source. A pair of reset transistors initializes the potential of the gate and the reference potential. A potential control circuit controls a potential difference between the gate and the drain to a predetermined value when the potential of the gate and the reference potential are initialized.

The invention discloses an automatic temperature compensation circuit and method based on a thermal flowmeter, and relates to the technical field of temperature compensation, and the compensation circuit comprises a constant current source module used for driving the thermal flowmeter; the Wheatstone virtual bridge arm is used for acquiring a changed digital-to-analog converter output voltage value output by the controller, and performing voltage conversion on a first voltage and a second voltage which are output on the thermal flowmeter due to the change of the external temperature according to the output voltage value to obtain a third voltage; the digital-to-analog converter is used for performing correction compensation on the third voltage according to the correction compensation value calculated by the controller; and the differential amplification module adopts a differential amplifier to amplify the third voltage and the fourth voltage output by the thermal flowmeter, and outputs a compensated flow signal. The compensating circuit is simple in structure and higher in reliability and precision, and compared with a digital potentiometer, the output value of the Wheatstone virtual bridge arm is changed by using the output value of the digital-to-analog converter, so that the adjusting resolution is higher.

The invention relates to the technical field of battery self-discharge testing, in particular to a zero-impedance-based battery self-discharge testing device and a zero-impedance-based battery self-discharge testing method. The battery self-discharge testing device comprises a connector module; the current detection unit comprises a sampling resistor Rsense and a differential amplification circuit, and the sampling resistor Rsense is connected in series in a current input loop; the differential amplification circuit is in bridge connection with the two ends of the Rsense of the sampling resistor and outputs a voltage signal proportional to the self-discharge current Idischarge current; the input end of the voltage detection unit is connected with the four-wire system voltage test terminal, and the open-circuit voltage VOCV of the battery to be tested is sampled in real time; the controllable voltage source module is used for outputting a dynamic compensation voltage Vapplied which is equal to the sum of VOCV and Idischarg * Rcircit, wherein the Vapplied is equal to VOCV + Idischarg * Rcircit; the controller module is used for calculating the real-time voltage drop of the total impedance Rcircuit of the circuit based on the VOCV and the Idischarge, and dynamically adjusting the output of the controllable voltage source, so that the terminal voltage of the battery to be detected is locked as the VOCV; and when the terminal voltage of the to-be-detected battery is stabilized within the range of VOCV + / -0.0001%, determining that the to-be-detected battery enters a constant potential mode, and continuously recording the current value until the current value is stable.

The invention relates to the technical field of intelligent control systems, in particular to an intelligent control system of a tumor electric field treatment device, which comprises a resistivity acquisition module for measuring tumor electrical impedance under differentiated frequencies by using a four-electrode measuring instrument, recording resistivity data changing along with time, enhancing the signal-to-noise ratio of signals by using a differential amplification technology, and acquiring the tumor electrical impedance by using the resistivity acquisition module; and calibrating the reading of the instrument, and generating a calibrated resistivity parameter set. According to the method, by analyzing the correlation between tumor electrical impedance and gene expression data, accurate adjustment of treatment electric field parameters is achieved, the treatment pertinence and the treatment effect are improved, the method allows personalized adjustment of a treatment scheme according to specific biomarkers of tumors, optimal matching of the electric field parameters and specific tumor characteristics of patients is ensured, and the treatment effect is improved. The application of clustering analysis realizes fine group division in patients with different tumor types or stages, so that the electric field treatment can be optimized according to specific tumor biological behaviors, and the phenomenon of one-time cutting possibly occurring in traditional treatment is avoided.

The invention discloses a seesaw type optical fiber end face weak force sensor which comprises a seven-core optical fiber, a seesaw type additive structure and an interference light beam. The seven-core optical fiber is composed of a central main fiber core and six symmetrically-distributed auxiliary fiber cores. The seesaw-type additive structure is composed of a short vertical beam, a vertical beam on a central main fiber core of the seven-core optical fiber and a cross beam connected to the vertical beam, and the whole structure is prepared through the two-photon polymerization technology of a femtosecond laser processing platform; the interference light beam is composed of two light beams in an interference cavity, wherein the lower surfaces of the left side and the right side of the seesaw-type additive structure are aligned with the end faces of two auxiliary fiber cores on the left side and the right side of the seven-core optical fiber. According to the invention, a two-photon polymerization technology is used to build an additive structure on the end face of the seven-core optical fiber, so that the sensing structure is small in overall size and is suitable for application in a limited space; the Fabry-Perot interferometers on the two sides of the sensing structure are connected in parallel to form an optical dynamic vernier structure, the sensitivity is improved through differential amplification of weak mechanical disturbance, and the anti-interference capability is enhanced through common-mode denoising.

A high-speed, low-noise laser signal detection apparatus, comprising a low-noise linear regulated power supply and a laser detection processing module. The low-noise linear regulated power supply (01-03) comprises an isolation unit (01), a voltage regulation and filtering unit (02), and a reference unit (03). The laser detection processing module (04-09) comprises a laser light signal detection input unit (05), a bias unit (04), a differential amplification unit (07), an active filtering unit (08), and an output interface unit (09). An output end of the voltage regulation and filtering unit (02) is connected to the reference unit (03) and the laser detection processing module (04-09). The reference unit (03) is connected to the bias unit (04) and is configured to provide a reference voltage to the bias unit (04). The bias unit (04) is configured to provide a bias voltage to the differential amplification unit (07). The differential amplification unit (07) comprises a multi-stage in-phase proportional differential amplification circuit, and the active filtering unit (08) comprises a multi-order active low-pass filter. According to the high-speed, low-noise laser signal detection apparatus, the detection bandwidth of a laser signal can be expanded, the signal-to-noise ratio of high-frequency pulse measurement can be reduced, and the anti-interference characteristics of a power supply can be improved.

The invention discloses a detection device and a detection system for harmonic oscillator capacitors of a hemispherical resonator gyroscope, and relates to the technical field of capacitor detection, the detection device comprises a signal detection circuit, a modulation compensation circuit, a differential amplification circuit and a control circuit, the signal detection circuit is connected with the output ends of the two harmonic oscillator capacitors; the modulation compensation circuit is correspondingly connected with two input ends of the signal detection circuit; the differential amplification circuit is correspondingly connected with two output ends of the signal detection circuit; the control circuit is configured to output modulation voltage to the two input ends of the modulation compensation circuit according to a voltage signal of the output end of the differential amplification circuit, and zero setting is carried out on voltage at the connecting positions of the two output ends of the modulation compensation circuit and the two input ends of the signal detection circuit. According to the invention, the modulation compensation circuit is adopted to enable the output ends of the two harmonic oscillator capacitors to work near zero voltage, the circuit has the characteristics of ultrahigh linearity, extremely low temperature drift, rapidness and stability, errors caused by power supply drift can be eliminated, and the detection precision is improved.

The invention provides an infrared detector reading circuit based on a dark current suppression structure, which comprises a dark current suppression circuit, an integrating circuit, a double sampling circuit, a source follower, a differential amplification circuit and an output buffer circuit which are electrically connected in sequence, and also comprises a sequential logic circuit, the dark current suppression circuit is used for generating a controllable current which is not influenced by temperature change, and the current is mirrored and then used for counteracting the dark current of the infrared detector; the sequential logic circuit is used for providing row selection logic, column selection logic and a sampling time sequence when a target pixel is selected from an infrared detector pixel array; the reading circuit can read the current signal of the target pixel according to the row selection logic, the column selection logic and the sampling time sequence; according to the invention, the signal-to-noise ratio of the readout system is improved by suppressing dark current, the function of reading out according to the column is realized based on the sequential logic circuit, the noise interference among the readout circuits in the array can be effectively reduced, and the focal plane array readout circuit is suitable for preparing a large-array-scale focal plane array readout circuit.

The invention relates to the technical field of analog integrated circuits, and discloses an LDO (Low Dropout Regulator) frequency compensation circuit based on a voltage-controlled current source, which comprises an input differential amplification module, a power regulation module, a frequency compensation module and a feedback voltage division module, and is characterized in that the output end of the input differential amplification module is electrically connected with the input end of the frequency compensation module; the frequency compensation module comprises a voltage-controlled current source and a compensation capacitor C1, the compensation capacitor C1 is matched with the voltage-controlled current source to adjust the loop frequency response, through a multi-stage current mirror and a Miller compensation network, pole distribution is optimized in a targeted mode, the Miller effect of the compensation capacitor C1 is matched, the dominant pole frequency can be actively lowered, a dominant pole is made to be away from a high-frequency area, and the loop phase margin is guaranteed; the self-excited oscillation is fundamentally suppressed, and the output voltage is stable and free of fluctuation.

Provided is a differential amplifier comprising: a first differential amplification circuit that has a first input terminal, a second input terminal, a first output terminal and a second output terminal which respectively output a first output signal and a second output signal; an RC filter that filters the first output signal and the second output signal and outputs them; a second differential amplification circuit that has a third input terminal and a fourth input terminal to which the first output signal and the second output signal filtered by the RC filter are respectively input and a third output terminal which outputs a third output signal; and a third amplification circuit that has a fifth input terminal to which the third output signal is input and a fourth output terminal which outputs a fourth output signal according to the third output signal.

The invention relates to a high-precision accelerometer signal pseudo-differential digital conversion circuit and a working method. The circuit comprises an I-V conversion circuit, a pseudo-differential amplification circuit and an AD conversion circuit. The I-V conversion circuit is used for converting a current signal output by an accelerometer into a voltage signal, filtering high-frequency interference and realizing impedance matching with the pseudo-differential amplification circuit so as to reduce signal distortion; the pseudo-differential amplification circuit is used for differentiating the ground and an input signal so as to reduce the influence of common-mode interference on the detection precision of the circuit, and adjusting the amplitude of an input voltage signal at the same time; and the AD conversion circuit is used for performing high-precision digital conversion on the input pseudo-differential voltage signal. According to the invention, I-V conversion with high common-mode noise suppression is realized, and high-precision voltage signal digital conversion is also realized.

The utility model belongs to the technical field of human body pulse detection, and discloses a pulse amplifying circuit based on a pressure sensor and a pulse signal acquisition system, and the circuit comprises the pressure sensor, a first-stage amplifying circuit, a second-stage amplifying circuit, a third-stage amplifying circuit, a fourth-stage amplifying circuit and a reference circuit, the signal input end of the first-stage amplification circuit receives an original pulse signal output by a pressure sensor and then outputs a differential amplification signal, the signal input end of the second-stage amplification circuit receives the differential amplification signal and then suppresses a common-mode signal and outputs a second amplification signal, and the signal input end of the third-stage amplification circuit receives the second amplification signal and then outputs the third amplification signal. The isolated direct current passes through a signal and outputs an alternating current signal in a following mode, a fourth-stage amplifying circuit receives the alternating current signal and then amplifies and filters the alternating current signal, and an amplified pulse signal is obtained and output. According to the utility model, the cost of the product is reduced, the circuit is simplified, the practicability is enhanced, and the pulse signal can be accurately measured.

A TMR sensor-based non-contact current measuring device, comprising a TMR sensor module, a differential processing module, a signal processing module, and an intelligent control module. The TMR sensor module is used for acquiring a detection signal and transmitting the detection signal to the differential processing module; the differential processing module is used for performing differential amplification, filtering and conversion processing on the detection signal to output a single-ended signal; the signal processing module is used for performing inverting amplification processing on the single-ended signal to obtain a control signal; and the intelligent control module is used for receiving the control signal and implementing control. According to the TMR sensor-based non-contact current measuring device, a current detection signal is obtained on the basis of the TMR sensor module, differential amplification, filtering and conversion processing are performed on the current detection signal by means of the differential processing module to output a single-ended signal, and inverting amplification processing is performed on the single-ended signal by means of the signal processing module, thereby improving the detection signal precision, and thus improving the accuracy of current detection.

The invention discloses a silicon carbide MOSFET parallel current sharing system and method for a pulse power supply, and belongs to the technical field of SiC MOSFET parallel current sharing, the system comprises a main power circuit connected with a plurality of SiC MOSFETs in parallel and an active driving circuit, when the SiC MOSFETs are turned on, a source inductor generates an induced voltage in direct proportion to the current rising rate, and when the SiC MOSFETs are turned on, the active driving circuit drives the main power circuit to rotate; current sharing when a plurality of SiC MOSFETs are connected in parallel is realized through an in-phase amplification circuit used for detecting and amplifying an induced voltage, a differential amplification circuit used for detecting and comparing an induced voltage value, and a proportional current source circuit is controlled to extract a SiC MOSFET gate drive current. By adopting the method, the unbalanced current can be suppressed, the balance of the current flowing through each branch of the parallel SiC MOSFETs is ensured, the SiC MOSFET device in the high-voltage pulse power supply is effectively protected, and the working reliability of the circuit is improved.

The invention discloses an electric leakage detection method based on wavelet transform harmonic suppression, and the method comprises the steps: synchronously collecting a current signal through a dual-channel differential sampling circuit, and obtaining two paths of differential voltages; after common-mode interference is eliminated through differential amplification and impedance matching, low-pass filtering and digital conversion are carried out; extracting signal multi-scale energy characteristics by using wavelet decomposition, and setting a threshold value to separate leakage low-frequency components from high-frequency noise; a pure electric leakage signal is obtained through inverse wavelet reconstruction, and a high-speed switching circuit compares a preset threshold value to trigger a protection action. According to the scheme, differential sampling, impedance matching and wavelet analysis technologies are combined, the signal-to-noise ratio and the detection precision are effectively improved, the problems that in the prior art, electric leakage signals are prone to interference and slow in response speed are solved, and the reliability and the real-time performance of electric leakage protection are remarkably improved.