27656 results about "Resistor" patented technology

The invention discloses an automatic control method and system for secondary granulation of a high-voltage zinc oxide resistor disc, relates to the technical field of intelligent manufacturing of power equipment, and solves the problems of out-of-control particle morphology caused by dynamic coupling parameter identification lag and control instability caused by multi-physical field parameter coupling in an existing method. According to the invention, a dynamic physical property parameter matrix is generated in real time based on multi-band dielectric relaxation spectrum analysis and terahertz wave tomography; predicting a fluidized phase change threshold value and an energy gathering area through multi-physics field coupling modeling; a time sequence attention deep reinforcement learning algorithm is adopted to generate a multi-field cooperative adjustment instruction; positioning a parameter conflict source and triggering decoupling compensation by combining a high-frequency vibration and acoustic emission combined monitoring module; performing closed-loop correction on the control network weight based on the laser spectrum data and a partial least squares regression model; the real-time performance of fluidization parameter identification, the stability of multi-field coupling control and the recovery efficiency of abnormal working conditions are remarkably improved, and meanwhile the batch consistency of the electrical performance of the resistor discs is guaranteed.

An aerial vehicle or another system having moving components may be configured with a capacitive sensing system for detecting body parts of humans or other animals within proximity. The capacitive sensing system includes conductive components provided in association with surfaces of housings within which motors rotate propellers or other objects. The capacitors are coupled to circuits including transistors, resistors, capacitors or other features that are configured to determine levels of capacitance on the conductive components during operations of the aerial vehicle or other system. When a body part approaches a conductive component, and disrupts a level of capacitance on a capacitor coupled to the conductive component, a change in the level of capacitance on the capacitor is detected. Where the change exceeds a predetermined threshold, predetermined actions such as stopping or otherwise altering operations of the motors may be performed.

The invention relates to the field of high-voltage direct-current power transmission, and aims to provide an MMC converter valve and method for realizing alternating-current and direct-current fault ride-through based on an energy consumption sub-module. On the basis of a topological structure of a conventional MMC converter valve, M energy consumption sub-modules which are sequentially connected in series and are the same in structure are arranged between a bridge arm inductor of each bridge arm and the midpoint of an upper bridge arm and the midpoint of a lower bridge arm, and each energy consumption sub-module comprises a main through-flow branch, an energy consumption branch and a bypass loop which are connected in parallel; in the main through-current branch, the half-controlled switching device T1 is reversely connected in parallel with a fly-wheel diode D1 of the half-controlled switching device T1, and then is reversely connected in series with the full-controlled switching device T2 and a reverse fly-wheel diode D2 of the full-controlled switching device T2; the energy consumption branch comprises an energy consumption resistor Rd, and the bypass branch comprises a bypass switch K. According to the invention, alternating current fault ride-through and direct current fault ride-through are integrated into the topology of the MMC converter valve, so that the integration level of the protection scheme is improved; voltage fluctuation during alternating-current fault ride-through can be effectively smoothed, and the stability during alternating-current fault ride-through is improved.

The invention discloses a fault ride-through hierarchical control method for a network-constructed converter, and the method comprises the steps: introducing a virtual resistor formed by fault current negative feedback into the voltage and current inner loop control of the network-constructed converter based on VSG control through a current inner loop dynamic amplitude limiting control layer after the converter enters a fault ride-through state, the size of the virtual resistor is adjusted in real time along with the amplitude of the fault current so as to carry out dynamic current limiting control on the virtual resistor; and the power outer loop dynamic compensation control layer dynamically adjusts an active power instruction value and a reactive power instruction value of the network construction type converter based on VSG control during the fault ride-through period according to the voltage drop degree of the power grid after the converter enters the fault ride-through state. And respectively performing active-frequency control and reactive-voltage control based on the active power instruction value and the reactive power instruction value. In addition, the method also comprises a state coupling and parameter self-adaption module. According to the method, the GFM converter can have better dynamic performance in the fault recovery stage.

The invention discloses a high-precision current detection circuit calibration system, and belongs to the technical field of current detection circuit calibration. Comprising a shunt resistor, a Hall sensor array, a chopping amplifier, a low-noise operational amplifier, a temperature sensor, an ADC acquisition unit, an RC low-pass filter, a signal conditioning unit, a main control unit, an environmental parameter adaptive compensation module and a gain adaptive adjustment module. After an original signal is obtained from a multi-channel sensor, a dynamic error model is constructed in combination with temperature data, a long-term imbalance trend is extracted by using a moving average or median filtering algorithm, and real-time compensation is performed through a pre-calibrated temperature-drift function, so that the system maintenance period is remarkably prolonged.

The invention discloses a control circuit of an electronic load, the electronic load and a power supply test system. The circuit comprises an MCU; the signal output end of the MCU is connected with the input end of the DAC module; the closed-loop control circuit comprises a first error amplifier, a mutual inductor, an MOS (Metal Oxide Semiconductor) tube, a current sampling resistor and a power supply end VBUS; a mutual inductor is arranged between a first error amplifier and an MOS tube of the closed-loop control circuit, a power supply end VBUS is connected with a drain electrode of the MOS tube through a primary side of the mutual inductor, a first secondary side of the mutual inductor feeds back an input signal of the first error amplifier, and a second secondary side of the mutual inductor feeds back a driving signal of the first error amplifier to the MOS tube. According to the invention, the dynamic response speed when the electronic load pulls the high-frequency current can be improved, and the test requirements of high precision and high dynamic response are met.

The invention discloses a SiC MOSFET gate oxide layer degradation monitoring method based on turn-off oscillation, and the method comprises the steps: measuring the drain-source current change rate diDS / dt when a SiC MOSFET is turned off through the source stray inductance voltage vcir, and carrying out the measurement of the gate oxide layer degradation of the SiC MOSFET based on the offset of the negative temperature sensitivity of the threshold voltage VTH in the diDS / dt and the positive temperature sensitivity of the electron mobility mu. Zero temperature sensitivity of a source stray inductance voltage negative peak value vcircmin is realized by adjusting a driving resistor RG and a negative voltage VEE during turn-off, and the gate oxide layer degradation degree of the SiC MOSFET is monitored under a selected monitoring driving resistor RGM and a turn-off gate voltage VEEM. The monitoring method is high in universality and has a good monitoring effect on degradation of gate oxide layers of SiC MOSFETs of different models; the temperature influence is extremely small, so that the device can work in an environment with large temperature fluctuation; a pin of a monitored device does not need to be used as a measurement interface, so that the system invasiveness is small; the parameter measurement methods are many and mature; and the method has great online application potential.

The invention provides a resonance elimination device and method for suppressing ferromagnetic resonance in a power system, and relates to the technical field of power system safety prevention and control. The resonance elimination device for suppressing the ferromagnetic resonance in the power system comprises a resonance elimination module used for consuming energy generated by the ferromagnetic resonance; an acquisition module; the detection module is used for detecting excitation inrush current between the neutral point of the voltage transformer and the high-voltage damping resistor in real time; the calculation module is used for calculating the rising edge slope of the magnetizing inrush current and calculating the offset voltage of the neutral point to the ground; the judgment module is used for continuously judging the relationship between the rising edge slope of the excitation inrush current detected in real time and each threshold value and the relationship between the numerical value of the neutral point to ground offset voltage detected in real time and each threshold value, and judging whether the system has a single-phase ground fault or not; and the control module controls the input of the harmonic elimination module. The resonance elimination device can accurately and quickly eliminate ferromagnetic resonance and effectively improve the resonance elimination efficiency of the ferromagnetic resonance.

The invention relates to the technical field of wireless communication, and provides a radio frequency low-noise amplifier which comprises an input matching module, a power amplification module, an output matching module, an RC attenuation module and an RC feedback module, the first end of the first inductor serves as the input end of the output matching module, the first end of the first inductor is connected with the output end of the power amplification module, the control end of the switch and the first end of the first adjustable resistor, and the second end of the first inductor is connected with the first end of the second inductor and the first end of the third capacitor. The output end of the switch is connected with the first end of the first capacitor and the first end of the second capacitor. The second end of the second capacitor is connected with the second end of the first adjustable resistor and the second end of the second inductor and used for being connected with a power supply. The second end of the first capacitor is connected with the second end of the third capacitor and serves as the output end of the output matching circuit. The radio frequency low-noise amplifier is adjustable in gain, low in noise and good in linearity performance.

The invention relates to the technical field of electromagnetic materials, and discloses a lossy multimode resonant metasurface unit and a multifunctional active coding wave absorber. The lossy multimode resonant metasurface unit comprises a lossy metal pattern layer, a supporting dielectric layer, an impedance matching dielectric layer and a metal ground layer which are sequentially arranged from top to bottom; the lossy metal pattern layer comprises a multi-mode resonator and a radio frequency PIN diode, the multi-mode resonator is used for realizing a plurality of resonance modes and playing a role in electromagnetic wave frequency selection, and the radio frequency PIN diode is used for playing a role of an adjustable resistor and adjusting the electromagnetic wave loss so as to realize intensity adjustment of reflected electromagnetic waves; every two adjacent multi-mode resonators are connected in a cascading mode through a radio frequency PIN diode and are combined to form a closed-loop pattern. The multifunctional electromagnetic wave absorber is simple in structure, has the constant phase scattering cancellation characteristic, and can independently regulate and control the reflection amplitude so as to solve the technical problem of an existing multifunctional electromagnetic wave absorber.

The invention relates to the technical field of power electronics, in particular to a filter equivalent circuit design simulation system suitable for an energy storage converter, which comprises a main circuit topology unit, a control strategy unit, a parameter optimization and design unit, a simulation engine unit and a performance evaluation unit, wherein the main circuit topology unit is used for building a filter equivalent circuit topology of the energy storage converter and configuring passive element parameters of an inductor, a capacitor and a resistor. According to the method, automatic high-robustness optimization of filter parameters is realized through genetic algorithm-particle swarm hybrid optimization, multi-objective collaborative optimization and digital twinning auxiliary optimization, and a'design-optimization-verification-iteration 'closed loop is formed by combining dynamic working condition evaluation, reliability modeling and artificial intelligence auxiliary analysis, so that the method has the advantages of high robustness and high robustness. The harmonic suppression capability, efficiency and long-term operation reliability of the filter are remarkably improved, the design period is shortened, and the development cost is reduced.

The invention relates to the technical field of wiring terminals, in particular to an intelligent testing method and system for the contact resistance of a wiring terminal, and the method comprises the following steps: adjusting the resistance testing frequency according to the environment temperature to adapt to different conditions, combining current and voltage data, analyzing the historical change trend of the resistance, predicting the potential change range, and obtaining the contact resistance of the wiring terminal through the current and voltage data. Evaluating the mutual influence with the resistor, judging the abnormal reason of the resistor, adjusting a test scheme according to fault diagnosis, predicting potential faults, and making a test plan. According to the invention, through environment induction and data analysis, the resistance test frequency is adjusted in real time to adapt to environment change, so that the resistance measurement in the test process is more sensitive and accurate, the response speed and data quality of the test process are improved, historical and current resistance data are automatically analyzed, potential faults can be effectively predicted and identified, and the test efficiency is improved. Problems caused by operation errors are reduced, and a prospective fault prediction function enables the adjustment of the test period to be more scientific.

The invention relates to the technical field of photovoltaic cells, and discloses a method for improving laser-assisted sintering contact uniformity and a processing device. The method comprises the steps that a probe presses a main grid of a first area on the front face of a battery piece, first laser power is used for scanning a second area on the front face of the battery piece in a laser scanning mode in the fine grid direction, first reverse bias voltage is applied to the battery piece, and a variable resistor adjusts the resistance value of the variable resistor according to the distance between scanning point positions and the probe so as to balance the bias voltage difference of different scanning point positions; performing laser-assisted sintering on the second area; the probe presses a main grid of a second area on the front face of the battery piece, laser scanning is conducted on a first area on the front face of the battery piece in the fine grid direction through second laser power, second reverse bias voltage is applied to the battery piece, the resistance value of the variable resistance piece is adjusted according to the distance between the scanning point position and the probe, and laser-assisted sintering of the first area is completed. According to the method, the bias voltage difference of different scanning point positions can be balanced, the interface contact difference of different areas can be balanced, and the battery performance and effect can be improved.

The invention discloses a charging and discharging control method and device for an elevator energy storage system, a medium and a product, and relates to the field of data processing. The method comprises the steps that real-time operation data such as the position and the load capacity of an elevator car are obtained, and the instantaneous power generation power and the power change rate of a traction machine are determined accordingly; determining a power change predicted value in a future preset time period based on the parameters, and obtaining the total amount of power generation energy required to be stored by the energy storage system through zero setting of a positive value, integral operation and efficiency compensation; according to the power change rate, the state of the energy storage unit and the power grid electricity price time period, the charging and discharging priorities fed back by the super capacitor, the lithium battery and the power grid are determined; controlling the bidirectional DC / DC circuit to switch charging and discharging modes according to the priority, and adjusting the PWM duty ratio of the brake resistor; and based on the charging and discharging mode and the duty ratio, charging and discharging control over the elevator energy storage system is achieved. According to the method, the problem of inaccurate real-time matching of the dynamic load and the energy fluctuation of the current elevator energy storage system can be relieved.

The invention relates to the technical field of field data acquisition, in particular to an on-line temperature self-compensation calibration method and circuit for a force measurement transmitter. The calibration method comprises the steps that a working strain gauge and a temperature compensation gauge are synchronously excited through a two-way precision constant current source, the working strain gauge and the temperature compensation gauge are consistent in material parameter and are located in the same temperature field, and output current values of the two-way precision constant current source are equal and are controlled by a high-precision reference voltage source and a sampling resistor in a closed-loop mode. According to the invention, differential signals of the working strain gauge and the temperature compensation gauge are decoupled in real time through double-path precise constant-current source excitation and synchronous ADC acquisition technologies, gradient compensation is carried out on the temperature change rate in combination with a dynamic weighting algorithm, a lag error of traditional fixed coefficient compensation in a transient temperature field is effectively eliminated, and the accuracy of temperature compensation is improved. And online self-compensation of the temperature drift of the strain gauge is realized.

The invention provides a method and system for achieving elevator energy feedback data communication. The method comprises the steps that multi-modal data are collected, and fault features are extracted, encrypted and packaged; and after decryption, phase deviation of elevator operation and power grid voltage is calculated by utilizing an algorithm, a current phase is synchronously fed back, and a feedback instruction is generated. Uploading the harmonic suppression parameter to an energy center, calculating a demand, generating a region-level feedback strategy, dynamically distributing a feedback power upper limit, synchronizing the harmonic suppression parameter, and obtaining region-level feedback data. And aggregating feedback data, and setting a global optimization target, including cost minimization, feedback maximization and carbon emission reduction. And calculating feedback energy and carbon integral according to a target adjustment algorithm, automatically settling to an operator account, and adjusting the target of the next period. Through an algorithm and an optimization mechanism, the problem of energy waste of a brake resistor in a traditional feedback technology is solved, the feedback efficiency is improved, and energy waste is reduced.

The invention relates to the technical field of active damping control, and discloses a bidirectional DC-DC power supply active damping control system and method, and the system comprises a front-end AC input rectification module, an LLC resonant circuit, and a Buck converter module: the front-end AC input rectification module is used for converting an AC input voltage into a DC voltage; the LLC resonance circuit is used for inverting the rectified direct current voltage into alternating current with a set frequency and transmitting the alternating current to a secondary side through a transformer; and the Buck converter module is used for rectifying an alternating current signal and adjusting the alternating current signal into a required direct current output voltage, and further comprises an LC filter and an active damping control module. By adopting the active damping control method, the resonance peak caused by the LC filter can be effectively suppressed without additionally adding a physical resistor, so that the fluctuation of the output voltage is limited. According to the control strategy, the problems of power loss and heating caused by a traditional passive damping method are avoided, and the energy efficiency of the system is remarkably improved.

The invention discloses an electronic load system, a power supply test method, an electronic device and a storage medium, and relates to the technical field of electrics. A main control circuit can provide a reference voltage for a current sampling and control circuit, and can also obtain load current setting parameters; the current sampling and control circuit determines a control voltage mainly by acquiring a sampling voltage and comparing the sampling voltage with a reference voltage so as to control an on-resistor in the power circuit through the control voltage and further control the magnitude of the current passing through the on-resistor, and meanwhile, the change rate of the current can be controlled due to a load current parameter. Therefore, the rapid change of the load current can be realized. Therefore, the technical problems of how to realize the rapid change of the current and improve the accuracy of the test result can be solved, and the technical effects of meeting the rapid change requirement of the current and improving the test result are achieved.

The present application discloses a method and apparatus for detecting insulation impedance of a direct current side of a photovoltaic inverter. The method includes the following steps: sampling a voltage of a protective earthing and a voltage of the positive terminal of a direct current bus respectively; obtaining a first voltage difference between voltages of the protective earthing at different moments and a second voltage difference between voltages of the positive terminal of the direct current bus at different moments; and calculating the insulation impedance of the direct current side of the photovoltaic inverter based on the first voltage difference, the second voltage difference, a resistance of an equivalent resistor between each terminal of the photovoltaic inverter and a signal ground, and resistances of equivalent resistors between the positive terminal and the negative terminal of the direct current bus and the protective earthing.

The invention discloses a sensitivity compensation method and system based on a TMR sensor. The method comprises the steps that a temperature compensation circuit introduces a negative temperature coefficient temperature sensitive resistor to be connected with a TMR current sensor in series; a fitting compensation technology is used, the corresponding relation between the temperature and the sensitivity of the sensor is accurately measured, data fitting is carried out through a least square algorithm, and a mapping curve of the temperature and the sensitivity is obtained; constructing and training a neural network model for learning and simulating a complex mapping relationship between environmental factors of a space geomagnetic field and temperature and measurement output of the TMR current sensor; and performing real-time correction compensation on the original output signal of the TMR current sensor by using the trained neural network model according to the environment temperature information acquired by the upper computer in real time and the correction factor predicted by the model. Through a unique compensation mechanism and an optimization algorithm, the accuracy of current signal acquisition and the stability of the system are remarkably improved, and the influence of environmental factors is reduced.

The invention discloses a memristor-based signal detection circuit and method, a receiver and equipment, and relates to the field of wireless communication, a voltage source module of the circuit is connected with a voltage input end of a memristor array module, and a current source module is connected with a current input end of the memristor array module; the current output end of the memristor array module is connected with the reverse input end of the operational amplifier module and one end of the feedback resistor module, the other end of the feedback resistor module and the output end of the operational amplifier module are connected with the input end of the multiplier module, and the output end of the multiplier module is connected with one end of the resistor module. The voltage of the voltage source module is set according to the emission vector set; the current of the current source module is set according to the received radio frequency signal, and the conductance value of the memristor is set according to the channel matrix, so that a relatively low bit error rate of signal detection can be realized on the basis of greatly reducing calculation time and power consumption, and meanwhile, the requirement on programmable bit precision of the memristor is also reduced.

Embodiments of the present application discloses a totem-pole power factor correction circuit and a power supply equipment. The circuit includes a sampling unit and a detection control unit. The sampling unit includes a first sampling resistor and a second sampling resistor, the first sampling resistor being electrically connected between a second connection point and an anode of a first diode, and the second sampling resistor being electrically connected between the second connection point and a cathode of a second diode. The detection control unit may output a control signal through a voltage at both terminals of the first sampling resistor or the second sampling resistor or a voltage at both terminals of the first sampling resistor and the second sampling resistor connected in series to drive the third switch or the fourth switch to turn off, thereby effectively avoiding components damage caused by a late turn off of the third switch or the fourth switch.

The invention relates to the technical field of data processing, in particular to a metal alloy current detection resistor detection data processing method and system. The method comprises the following steps: acquiring a plurality of current data and voltage drop data, and obtaining each sub-window of each current data; obtaining the stability degree of each sub-window of each piece of current data, and obtaining the authenticity of each sub-window of each piece of current data according to the stability degree of each sub-window of each piece of current data and the relation between the numerical value change of the current data and the numerical value change of the voltage data; acquiring a reference window of each current data according to the authenticity; according to the method, the fuzzy entropy value of each current data is obtained according to the reference window of each current data, each abnormal data is obtained according to the fuzzy entropy value of each current data, the judgment of the abnormal condition of the metal alloy current detection resistor is completed, the noise influence is avoided, and the accuracy of abnormal detection is improved.

The invention discloses a photovoltaic inverter topology circuit and a control method thereof. The photovoltaic inverter topology circuit comprises a plurality of operational amplifiers, a plurality of MOS tubes, a plurality of resistors, a plurality of connectors, a plurality of capacitors and a plurality of diodes, the in-phase end of an operational amplifier U1 in the operational amplifiers is connected with one end of a resistor R2, the source electrode of an MOS tube Q2, the anti-phase end of the operational amplifier U1 in the operational amplifiers is connected with one end of a resistor R3, the source electrode of an MOS tube Q1, and the output end of the operational amplifier U1 in the operational amplifiers is connected with the other end of the resistor R3; the in-phase end of the operational amplifier U5 is connected with the cathode of the diode D4, the anti-phase end is connected with the in-phase end of the operational amplifier U6, the cathode of the diode D2 and one end of the capacitor C1, and the output end is connected with the anode of the diode D2; the inverting end of the operational amplifier U6 is connected with the output end and one end of the resistor R1; the grid electrode of the MOS tube Q1 is connected with the grid electrode of the MOS tube Q2, and the drain electrode is connected with one end of the resistor R4 The drain electrode of the MOS tube Q2 is connected with the other end of the resistor R1; the anode of the diode D4 is connected with the P1 end of the connector; the other end of the resistor R4 is connected with the P2 end of the connector; the other end of the capacitor C1 and the other end of the resistor R2 are grounded.

The invention provides a two-stage converter topological structure and a control method. The two-stage converter topological structure comprises a power supply, a DAB circuit, a Boost circuit, an input capacitor and a load resistor, a power supply voltage, an actual voltage of a second multiplexing capacitor and an actual output voltage of a DAB circuit are collected and input into a controller; the controller calculates the power supply voltage, the actual voltage of the second multiplexing capacitor and the actual output voltage of the DAB circuit to obtain a PWM driving signal of each switching tube; the turn-on time difference of the primary side switch tube and the secondary side switch tube in the DAB circuit is controlled through the PWM driving signal of each switch tube, and the output power of the two-stage converter is adjusted; the turn-on time of each switch tube in the Boost circuit is controlled through the PWM driving signal of each switch tube, and the voltage gain of the two-stage converter is adjusted; and the electric energy conversion efficiency is improved while electric isolation is realized.

The invention discloses an anode potential adjusting device and an electron accelerator, the electron accelerator comprises a first electrode plate, a second electrode plate and a high-voltage end, the high-voltage end is connected with the first electrode plate, the anode potential adjusting device comprises a rheostat and an oil cylinder, and the rheostat is connected with the oil cylinder. The rheostat is connected between the first electrode plate and the second electrode plate; the oil cylinder is connected with a hydraulic pump through a hydraulic oil pipeline, a piston of the oil cylinder is connected with the rheostat, and the piston is used for driving the rheostat to adjust the resistance value. According to the invention, the change condition of the beam current can be observed in real time under the condition that the high voltage and the beam current exist simultaneously, so that the optimal anode resistor can be optimized more easily, and the electron gun can be in the optimal working state.

The invention provides a preparation method of an island and beam film structure micro differential pressure sensor with an IC (Integrated Circuit), which comprises the following steps: arranging an N-type buried layer, a P-type buried layer and an island film structure on an SOI (Silicon On Insulator) silicon wafer, then connecting the SOI silicon wafer with a double-parabolic silicon wafer, and arranging a medium isolation groove, an N-type buried layer connecting region, a P well, a P-type buried layer connecting region, a sensitive resistor, a P-type base region, an N-type base region, an N-type emitter region and a P-type emitter region on the SOI silicon wafer. According to the invention, the preparation of the complementary bipolar transistor double-buried layer is completed by combining a semiconductor manufacturing technology and an MEMS manufacturing technology under the condition of not using an epitaxial process; the process flow is integrally simplified, and the preparation efficiency is improved.

The utility model relates to a pre-charging circuit and an energy storage power supply, in the pre-charging circuit, a control module samples an input voltage of an input power supply and outputs a first control signal to a second switch module and a pre-charging protection module when the input voltage is within a preset range; the second switch module is switched on when receiving the first control signal to control the first switch module to be switched on, so that the input power supply supplies power to the load through the first switch module and the pre-charging resistor; when the pre-charging protection module receives the first control signal, the pre-charging protection module transmits the first control signal to the third switch module after delaying a preset time; and the third switch module is switched on when receiving the first control signal to control the power supply on-off module to be switched on, so that the input power supply supplies power to the load through the power supply on-off module, and meanwhile, the input power supply does not supply power to the load through the first switch module and the pre-charging resistor. According to the invention, the circuit can be prevented from being damaged due to overvoltage during pre-charging, and the safety of the circuit is improved.

A power circuit for a computer system is disclosed. The power circuit includes a voltage regulator circuit and a pull-down circuit. While activated, the voltage regulator circuit generates a particular voltage level on a regulated power supply node. In response to the voltage regulator circuit being deactivated, the pull-down circuit couples a first resistor between the regulated power supply node and a ground supply node. After a period of time has elapsed since the deactivation of the voltage regulator circuit, the pull-down circuit decouples the first resistor, and couples a second resistor, whose value is greater than the first resistor, between the regulated power supply node and the ground supply node.

The invention discloses a PUF (Physical Unclonable Function) generation device and a PUF generation method based on a magnetoresistor or a magnetosensitive current sensor. The signal acquisition and processing module acquires a voltage output signal of each magneto-sensitive current sensor and calculates a voltage effective value and a zero offset value; the signal acquisition and processing module uses the calculated effective value output by each magneto-sensitive current sensor to obtain the current value of the conductor to be measured; and the PUF processing module correspondingly generates a digital code of 1 or 0 according to the zero offset value of each magneto-dependent current sensor, and takes the obtained n 1 or 0 digital code sequences as a generated physical unclonable function PUF for digital identity authentication. According to the method, the PUF sequence is generated by adopting the own characteristics of the TMR, the characteristics of good confidentiality, simple scheme, high practicability and the like are achieved by utilizing the randomness of the process, an additional PUF chip does not need to be added, and the additional cost is not increased. With the increase of the TMR number, the higher the measurement accuracy is, the higher the safety is.