99 results about "Instrument amplifier" patented technology

The invention discloses an output voltage detection method and system based on an aviation power supply, and relates to the technical field of aviation power supply voltage detection. A differential voltage sensor is connected to the output end of an aviation power supply, a high-frequency suppression capacitor is connected in parallel, the sampling rate of 20-50 times of the working frequency is set according to the type of the power supply, and the signals are collected and converted into analog voltage signals; the analog signal is subjected to two-stage filtering, is amplified to 0-5V through an instrument amplifier, and is converted into a digital voltage sequence through a 16-bit ADC (Analog to Digital Converter); calculating AC power supply effective value, peak value and other parameters, DC power supply average value, ripple coefficient and other parameters; comparing the characteristic parameters with a preset threshold value, determining that the characteristic parameters exceed the threshold value and recording related information; and a detection result is transmitted to a monitoring terminal through an RS485, data is locally stored, and a switching value is output to an alarm device when the data is abnormal. The method adapts to aviation power supply load fluctuation and environment temperature change, detection precision is high, data transmission and storage are safe, abnormity is accurately identified and early warning is carried out in advance, and aviation power supply operation and maintenance reliability and efficiency are improved.

The invention discloses a low-noise and high-precision analog front-end circuit for biological signal acquisition. The low-noise and high-precision analog front-end circuit comprises a chopping capacitance coupling type instrument amplifier circuit, a switched capacitor type programmable gain amplifier circuit and a Sigma-Delta analog-to-digital converter modulator circuit. T-type capacitance feedback, chopping modulation and programmable technologies are introduced on the basis of an existing amplifier, and the low-noise and programmable gain functions of the pre-amplifier are achieved. Through the three-order one-bit quantized feed-forward chopping type Sigma-Delta modulator, the signal to noise ratio and the effective bit number of the signal are improved. Compared with the prior art, the analog front-end circuit not only has the capability of changing the gain multiple according to the bio-electricity signal, but also has the low-noise and high-precision signal processing effect, and the problems that a traditional analog front-end circuit is large in noise and low in signal processing precision are solved. In addition, the biological signal acquisition-oriented circuit provided by the invention can also be used in other analog front ends, such as an audio processor and the like, and is wide in application range.

The invention provides a temperature sensor for rapid calibration and a calibration method of the temperature sensor, and the temperature sensor comprises a bias module which is used for providing a bias current for a temperature sensing module; the temperature sensing module is used for determining a first VBE voltage and a second VBE voltage according to the bias current, generating a voltage signal in positive correlation with the temperature through a VBE voltage difference between the first VBE voltage and the second VBE voltage, and transmitting the voltage signal to the analog-to-digital conversion module and the instrument amplifier respectively; the analog-to-digital conversion module is used for determining a first temperature value through the voltage signal and the original reference voltage of the temperature sensor; the instrument amplifier is used for determining a second temperature value through the voltage signal; wherein the temperature difference value between the first temperature value and the second temperature value is used for calibrating the original reference voltage to obtain the target reference voltage. According to the embodiment of the invention, the environment requirement for temperature sensor chip calibration can be greatly reduced, the calibration time of the chip is shortened, and the production efficiency of the chip is improved.

The utility model aims to provide the testing device based on the arm model heat flow, which is low in cost, can meet uv-level voltage testing requirements, can realize voltage testing of a plurality of channels, and can improve the testing efficiency. The device comprises an arm model, a heat flux sensor, a temperature sensor, an operational amplifier, an instrumentation amplifier, an analog-to-digital converter and a main control board, the heat flux sensor and the temperature sensor are both mounted on the surface of the arm model, the temperature sensor is mounted on the surface of a product, the temperature sensor is connected with the main control board, and the operational amplifier is connected with the main control board. The heat flux sensor is connected with the input end of the operational amplifier, the operational amplifier increases input impedance, the output end of the operational amplifier is connected with the input end of the instrument amplifier and amplifies and converts signals into differential analog signals, the output end of the instrument amplifier is connected with the 24-bit analog-to-digital converter, and the analog-to-digital converter is connected into an external upper computer through the main control board. The device is applied to the technical field of heat flux testing.

The invention relates to the technical field of amplifiers, and discloses an analog-to-digital converter combination instrument amplifier which comprises a first-stage amplifier, the first-stage amplifier is in signal connection with a second-stage amplifier, the second-stage amplifier is in signal connection with a front-end low-pass filter (LPF), the front-end low-pass filter (LPF) is in signal connection with an analog-to-digital converter (ADC), and the analog-to-digital converter (ADC) is in signal connection with the analog-to-digital converter. And an unbalanced input-to-balanced differential circuit output module is arranged between the second-stage amplifier signal and a front-end low-pass filter (LPF). From the perspective of signal processing and conversion, a precise signal transition bridge is constructed by adding an unbalanced input-to-balanced differential circuit output module, unbalanced signals output by a second-stage amplifier are converted into double-end balanced differential signals, common-mode noise interference is effectively resisted through a differential transmission mode, the signal purity is guaranteed, and the signal quality is improved. The front-end low-pass filter and the analog-to-digital converter are adaptive to differential signals, so that the signal transmission is stable and anti-interference, and the analog-to-digital conversion is more accurate.

The invention provides a frequency converter embedded current waveform analysis method and system and a medium, and relates to the technical field of current waveform analysis, and the method comprises the steps: obtaining a sampling circuit configured in a current path of a frequency converter; calculating the required total gain based on the original output voltage signal of the sampling resistor and the required input voltage of the analog-to-digital converter; the signal quality of the original output voltage signal is evaluated, the required total gain is dynamically distributed to an instrument amplifier and a programmable gain amplifier, the original output voltage signal is amplified and then passes through an analog-to-digital converter, and current waveform data is obtained for current anomaly analysis; when the signal quality is lower than a first threshold value, the gain share of the instrument amplifier is increased preferentially; when the signal quality is higher than a second threshold, the gain share of the programmable gain amplifier is increased preferentially. According to the invention, the technical problem of low accuracy of current waveform analysis in the prior art can be solved, and the technical effect of improving the accuracy of waveform analysis is achieved.

The invention relates to a signal amplification device and system for photoacoustic spectrometry, and relates to the technical field of photoacoustic spectrometry, and the device comprises a buffer which is connected with a crystal resonator and is used for receiving a photoacoustic spectrometry signal emitted by the crystal resonator, and outputting a first amplification signal according to the photoacoustic spectrometry signal; the instrument amplifier is connected with the buffer and is used for receiving the first amplified signal, providing a common-mode rejection ratio and outputting a second amplified signal based on the first amplified signal and the common-mode rejection ratio; and the digital control gain amplifier is connected with the instrument amplifier and the remote control end, and is used for performing gain adjustment in response to a remote control instruction sent by the remote control end, and outputting a third amplification signal as an amplified photoacoustic spectrum signal based on the adjusted gain and the second amplification signal. By adopting the device, the noise interference in the photoacoustic spectrum signal amplification process can be reduced.

The high-precision NDIR gas sensor comprises a gas detector, a signal processing circuit, a microprocessor with an analog-to-digital converter (ADC), a light source driving circuit, a power conversion circuit, a communication module and circuit, a screen driving circuit and a display. The signal processing circuit carries out preliminary amplification and analog filtering on output signals of the detector through an instrument amplifier, a band-pass filter and isolation, noise can be effectively removed, and the characteristics of target signals can be enhanced. A microprocessor with an analog-to-digital converter (ADC) collects signals and achieves digital filtering through FFT conversion, the signal quality is further optimized, and finally the detected gas concentration value is displayed on a display screen in real time. The system can realize high-efficiency signal processing on the premise of ensuring real-time performance, has the advantages of simple structure, easy realization, low cost and the like, and is suitable for various signal processing scenes including but not limited to the fields of industrial automation, sensor data processing, medical signal analysis and the like.

The invention relates to the technical field of integrated circuits, and discloses a high-pass filter circuit and a low-noise and high-common-mode-rejection-ratio high-speed instrument amplifier, and the low-noise and high-common-mode-rejection-ratio high-speed instrument amplifier comprises a high-pass filter circuit which is used for providing a high-pass filtering function; the input end of the current feedback instrument amplifier circuit is connected with the high-pass filter circuit and used for providing high input impedance and a high common-mode rejection ratio, and the input end of the transconductance amplifier circuit is connected with the output end of the current feedback instrument amplifier circuit and used for improving the load driving capacity; wherein the high-pass filtering circuit adopts a connection mode of a small-capacitance capacitor and an adjustable pseudo resistor to realize high-pass filtering, and the small-capacitance capacitor refers to an on-chip capacitor of which the capacitance value is less than 100pF so as to realize complete integration. The instrument amplifier effectively solves the problem that a traditional instrument amplifier cannot have high speed, low noise, high common-mode rejection ratio and direct-current voltage offset suppression at the same time.

The invention discloses a signal acquisition circuit for a brain-computer interface, and relates to the technical field of integrated circuits. The acquisition circuit comprises a sensing amplifier, wherein the sensing amplifier comprises a chopping modulation capacitance coupling instrument amplifier and a band-pass filter which are connected in series; the chopping modulation capacitance coupling instrument amplifier comprises an input main chopping modulator, an input capacitor, a negative feedback circuit, a first amplification circuit and a second amplification circuit which are sequentially connected in series; a pre-charging circuit, an input capacitor and a first amplifying circuit are connected to the input main chopping modulator in parallel, a positive feedback enhancing loop is connected to a second amplifying circuit in parallel, the first amplifying circuit and the second amplifying circuit are connected with a first direct-current servo loop and a negative feedback circuit in parallel, and a ripple suppression loop is connected to the second amplifying circuit in parallel. And the second amplification circuit is connected with the signal output end through the band-pass filter. The sensing amplifier in the acquisition circuit can output the electroencephalogram signals with higher quality, so that the quality of the acquired brain-computer interface signals is higher.

The invention relates to the technical field of measurement of long-distance and high-accuracy temperature measurement resistors, and particularly discloses a resistor temperature measurement method, which comprises a constant current source I, temperature measurement resistors RX and RY, a reference resistor RR, an analog switch, an instrument amplifier, an analog-to-digital converter and a microcontroller, the method comprises the following specific steps that S1, an analog switch controls a constant current source I to sequentially flow through temperature measurement resistors RX and RY and a reference resistor RR, and current generates a voltage on each resistor and is in direct proportion to the resistance value of the voltage; and S2, measuring the voltages of the temperature measuring resistors RX and RY and the reference resistor RR through an instrument amplifier and an analog-to-digital converter to obtain VX1, the voltage of the temperature measuring resistor RX under the forward current condition, VY1, the voltage of the temperature measuring resistor RY under the forward current condition, and VR1, the voltage of the temperature measuring resistor RR under the forward current condition. According to the resistance temperature measurement method, 0.00025 DEG C or better uncertainty can be obtained, and observable errors caused by thermoelectromotive force can be effectively eliminated.

The application discloses a kind of multi-modal flexible sensor adaptive signal conditioning system design method, belong to flexible sensor signal conditioning technical field.The present application overcomes the defects of poor universality, performance compromise, high cost of mass production of existing conditioning circuit, adopts layered decoupling and dynamic reconstruction system-level architecture: through multi-modal feature analysis and demand mapping modeling, the feature vector composition of scene recognition is determined;Design configurable analog front end, integrate instrument amplifier, transimpedance amplifier, charge amplifier, bridge amplifier four parallel processing sub-modules, wherein charge and bridge amplifier adopt self-designed architecture with dynamic adaptive gain adjustment capability;Build heterogeneous digital processing platform with NPU, CPU, DSP as core, through cross-modal data fusion, scene recognition engine, dynamic hardware configuration combined with feedforward and feedback, loadable algorithm library and closed-loop optimization control law, realize the real-time scene reconstruction of hardware parameters and digital algorithm;Combined with domestic single-chip selection, rigid-flex PCB and automatic calibration, meet the demand of low-cost mass production.The present application realizes the native adaptation and performance optimization of single hardware platform to voltage, current, charge, impedance and other types of sensor signals, and can be widely applied in robot dexterous hand, medical monitoring, intelligent bandage, consumer motion monitoring and industrial monitoring fields.

The invention discloses a constant transconductance circuit of a DDA instrument amplifier and the DDA instrument amplifier. The constant transconductance circuit comprises BJT input pair transistors and is used for converting a pair of differential input voltages into a pair of differential output currents and generating a pair of emitter voltages and a pair of collector voltages. When the pair of differential input voltages changes, the transconductance replica circuit generates transconductance replica current according to the pair of collector voltages so as to introduce the current change generated by the BJT input pair transistors along with the change of the pair of differential input voltages into the source degeneration circuit. Furthermore, a constant ratio between the pair of differential output currents and the pair of differential input voltages is ensured. The BJT device is adopted, and compared with a traditional CMOS transconductance circuit, the BJT transconductance circuit has lower noise and offset. By utilizing the source electrode degeneration and transconductance replication technology of input geminate transistors, constant transconductance can be maintained in a wider input voltage range, and high linearity can be maintained in a wide input range.

The application provides a kind of hollow core polarization maintaining optical fiber cutting machine tension control system and control method, belong to optical fiber cutting control technical field, system uses four layers architecture of perception layer, processing layer, control layer, execution layer: perception layer is measured by double strain gauge symmetrical compensation device and temperature sensor synchronous acquisition mechanics and environmental signal;Processing layer adopts Wheatstone bridge, instrument amplifier, low-pass filter, 16-bit ADC and temperature compensation unit to realize signal multistage conditioning;Control layer deploys feedforward adaptive PID compound control system, combined with optical fiber diameter-tension parameter library feedforward compensation and dynamic PID adjustment, and integrates step loading control and fault early warning mechanism;Execution layer adopts torque mode motor and outputs linear tension through lead screw mechanism.

A robotic system is provided, which automatically changes settings on an audio system. The audio system (e.g., an instrument amplifier, effect processor, etc.) typically includes one or more controls that impact the operation of the audio system. Correspondingly, the robotic system includes a device interface coupled to a control sequencer. The device interface adapts to one or more controls of the audio system that are to be changed. In this regard, the device interface includes one or more control couplers. Each control coupler is adapted to a corresponding control of the audio system to be changed. The control sequencer provides a control sequence to the device interface that causes the control coupler(s) to vary the settings on the audio system. In practical applications, a combination of sequence values of the control sequence can represent a sufficiently high number of samples to determine a responsive behavior of the audio system.

A kind of parallel machine current adding system belongs to the technical field of electronic equipment for measurement and testing, solve how to design a kind of hardware circuit simple, control precision high parallel machine current adding and system problem;The parallel machine current adding and system of the present application, comprising: multiple single machine current sampling circuits, parallel machine current adding and circuit;Single machine current sampling circuit includes: first differential amplifier circuit, first proportional regulating circuit, first unit inverter circuit, first digital potentiometer;Parallel machine current adding and circuit includes: instrument amplifier circuit, second proportional regulating circuit, second unit inverter circuit, second digital potentiometer and multiple proportional input end resistance;Digital potentiometer is applied to parallel machine circuit, and the resistance value of potentiometer is assigned by the number of parallel machine table set to realize the adjustment of amplification factor, replace the single proportional resistance resistance value of traditional resistance proportional circuit to realize the adjustment of amplification factor, hardware circuit is simple, amplification factor control is accurate.

The present invention belongs to the technical field of cardiopulmonary function detection, and specifically relates to a high-precision, sports-type, non-invasive portable cardiopulmonary function parameter measurement device, comprising a host computer and a slave computer, the slave computer comprising an electrocardiogram detection module, a chest impedance detection module, a microcontroller and a wireless communication module, the chest impedance detection module comprising a signal generator, a filter, a constant current source, an instrument amplifier, a common-mode filter, a detection circuit, a high-pass filter, a high-precision signal amplifier, a differential circuit and a voltage raising module; the slave computer also comprises an acceleration sensor, and the device ensures that electrocardiogram signals and chest impedance signals can be accurately detected even in a motion state, greatly reduces noise interference caused by motion, improves the recognition of data feature points by the host computer algorithm, makes the detection data more accurate, and fills the gap in the domestic non-invasive cardiopulmonary related equipment for exercise cardiopulmonary function.

The utility model provides a temperature protection circuit. The temperature protection circuit comprises an instrument amplifier sub-circuit, a subtraction operation amplification sub-circuit, a cold junction compensation sub-circuit and a hysteresis comparator sub-circuit, the forward input end and the reverse input end of the instrument amplifier sub-circuit are used for receiving first voltage converted by the thermocouple; the subtraction operation amplification sub-circuit comprises a first operational amplifier, the output end of the instrument amplifier sub-circuit is connected with the reverse input end of the first operational amplifier, and the output end of the cold junction compensation sub-circuit is connected with the positive input end of the first operational amplifier; the hysteresis comparator sub-circuit comprises a second operational amplifier, the output end of the subtraction operation amplification sub-circuit is connected with the reverse input end of the second operational amplifier, the output end of the second operational amplifier is used for being connected with a switch, and the switch can switch the switch state according to an output signal of the second operational amplifier. According to the utility model, no extra space is occupied, and the set values of the protection temperature and the recovery temperature can be adjusted as required, thereby being more flexible.

Implementations and methods of an audio amplifier having a special function of driving a speaker without generating electro-acoustic noise are described herein. The phenomenon is inherent in an analog circuit, and is caused by the propagation of sound and heat when an audio signal acts on a circuit element material. The structure which is more resistant to electromechanical stress is not easy to generate such noise, and the appropriate circuit can also eliminate the residual effect. Compared with the prior art, the tone quality is greatly improved, and a music player has a greater degree of freedom in the aspect of tone research and can play music more easily. Similar improvements are also obtained when the invention is used for driving loudspeakers of music making studios and all applications requiring optimal sound quality.

The invention belongs to the field of integrated circuits, and discloses a low-voltage high-precision instrumentation amplifier analog IC (integrated circuit) chip which takes a high-performance reference current source circuit without an operational amplifier as a biasing circuit. In the low-voltage design, in order to solve the problem that the signal-to-noise ratio of the instrument amplifier is gradually deteriorated, a rail-to-rail input and output structure is adopted. According to the invention, the folded cascode structure provides a large gain and also serves as a resistor to be connected with the Miller compensation capacitor to form an unconventional RC network, so that the zero point problem is ingeniously solved, the additional chip area is not increased, and the response speed of the instrument amplifier is also improved; the MOS capacitor is used as the compensation capacitor, compared with a traditional metal capacitor, the MOS capacitor has the advantages of being high in integration level, small in area and the like, and the chip area is greatly reduced while the compensation effect is achieved.

The utility model discloses a catalytic combustion type gas sensor signal conditioning circuit, which comprises an instrument amplifier circuit, a zero point adjusting resistor network and a passive low-pass filter circuit, and is characterized in that the zero point adjusting resistor network comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5; one ends of the first resistor R1, the second resistor R2 and the third resistor R3 are connected with the single chip microcomputer, the other ends of the first resistor R1, the second resistor R2 and the third resistor R3 are grounded through the fifth resistor R5, one end of the fourth resistor R4 is connected with input voltage, and the other end of the fourth resistor R4 is grounded through the fifth resistor R5.

The invention discloses an underground receiving system suitable for a borehole telemetering system, which comprises a differential pre-amplification receiving circuit, a differential filtering amplification circuit, a differential amplification circuit, a differential data acquisition circuit and a main control unit which are electrically connected together in sequence, the differential output signals Vout + and Vout-of the previous circuit are the differential input signals Vin + and Vin-of the next circuit, and the differential output signals Vout + and Vout-of the differential data acquisition circuit are sent to the main control unit for processing. According to the system disclosed by the invention, a fully differential circuit design is adopted, so that common-mode signal input is avoided. And a low-noise instrument amplifier is arranged in the differential pre-amplification receiving circuit, so that the signal input noise can be reduced, and the common-mode influence can be reduced. A single-end power supply is used for supplying power, the number of power supply groups and occupied space are reduced, and the device is suitable for being used in underground limited space.

The utility model discloses a kind of multi-loop processing CV mode electronic load instrument, it includes main control module, main power module, auxiliary power module, display module, button module, power amplifier module, communication board module and interface module.Main control module is core control unit, contains instrument amplifier, and difference proportional circuit, integrated operational amplifier circuit, advance adjustment circuit, lag adjustment circuit and analog switch, different input signal characteristics are adapted by flexible switching adjustment mode.The main power module and auxiliary power module provide stable power supply respectively;Display module and button module form man-machine interface;Power amplifier module drives high-power MOS tube to maintain constant voltage output;Communication board module supports multiple communication protocols;Interface module provides physical connection port for external equipment.The utility model significantly improves system stability and adaptability through multi-loop design, suitable for a variety of application scenarios.

The invention relates to the technical field of electromagnetic positioning, in particular to a five-degree-of-freedom sensor for electromagnetic positioning and an induction signal processing system, and the induction signal processing system adopts a three-stage circuit architecture: the first stage is an instrument amplifier pre-amplification circuit with input filtering and common-mode suppression functions; the low-noise amplifier is used for performing low-noise amplification on a microvolt-level original signal; the second stage is a Sallen-Key type active high-pass filter circuit and is used for suppressing power frequency and low frequency interference; and the third stage is a Sallen-Key type active low-pass filter circuit which is used for filtering high-frequency noise. Wherein the output of the pre-amplification circuit is connected to the third-stage low-pass filter circuit and then is cascaded with the second-stage high-pass filter circuit to jointly form a band-pass filter path, and finally, a stable analog signal with a high signal-to-noise ratio is output. The problems that a micro sensor is weak in signal, prone to interference and high in system complexity are effectively solved, and the performance and reliability of the electromagnetic positioning system in high-precision application scenes such as medical navigation and virtual reality are remarkably improved.

The invention discloses a strong PUF (Physical Unclonable Function) circuit for security protection of the Internet of Things, which comprises two TMR sensor arrays, two instrumentation amplifiers, two switched capacitor integrators and a comparator, and is characterized in that each TMR sensor array comprises a plurality of TMR sensor units, and the conduction number of the TMR sensor units in the two TMR sensor arrays is controlled through an excitation signal; two differential voltage signals are generated, two instrument amplifiers respectively carry out differential amplification on the two differential voltage signals to generate amplified voltage signals, two switched capacitor integrators respectively carry out sampling and accumulation on the amplified voltage signals to obtain sampled voltage signals, and the sampled voltage signals are output to a comparator. The comparator carries out voltage polarity judgment on the two sampling voltage signals to obtain a PUF response; the method has the advantages of high uniqueness and randomness, high stability, low bit error rate and high excitation-response pair number, and can meet the requirements of a high-reliability large-scale security authentication system.

The invention relates to the technical field of intelligent pots, and particularly discloses a temperature control system and method for an intelligent pot, and the system comprises a temperature collection module which comprises a temperature sensor and a signal conditioning circuit, and the signal conditioning circuit comprises an instrument amplifier and a low-pass filter which are electrically connected in sequence, the output end of the temperature sensor is electrically connected with the input end of the instrument amplifier; the signal input end of the core control unit is electrically connected with the output end of the low-pass filter; the power adjusting module comprises a PWM generating circuit and a power driving circuit, the control end of the PWM generating circuit is electrically connected with the PWM output end of the core control unit, and the input end of the power driving circuit is electrically connected with the output end of the PWM generating circuit; the self-adaptive power management unit comprises a DC-DC conversion circuit, and the DC-DC conversion circuit is electrically connected with the temperature acquisition module, the core control unit and the power regulation module; the problems that a temperature control system of an intelligent pot is unstable in structure, inaccurate in temperature measurement and weak in anti-interference capacity are solved.

The embodiment of the invention discloses a capacitive coupling chopping instrument amplifier circuit and a ripple calibration method. The circuit comprises a first chopping switch, an input capacitor, a first resistor, a second resistor, a two-stage operational amplifier circuit, a feedback capacitor, a second chopping switch and a ripple calibration module, the two-stage operational amplifier circuit comprises a plurality of first transistors and a plurality of second transistors which are used for signal amplification; the control end of the first transistor is connected with the first input end of the two-stage operational amplifier circuit, and the control end of the second transistor is connected with the second input end of the two-stage operational amplifier circuit; the ripple calibration module is connected with the first output end and the second output end of the two-stage operational amplifier circuit, samples signals of the first output end and the second output end of the two-stage operational amplifier circuit, and controls the access number of the first transistor and the second transistor according to the sampled signals; ripple waves generated by the chopping instrument amplifier circuit are reduced. The problem that a capacitor coupling chopping instrument amplifier circuit generates ripples due to offset voltage is solved.

The application discloses an output voltage detection method and system based on an aviation power supply, and relates to the technical field of aviation power supply voltage detection; a differential voltage sensor is connected to the output end of the aviation power supply, a high-frequency suppression capacitor is connected in parallel, a sampling rate of 20-50 times the working frequency is set according to the type of the power supply, analog voltage signals are collected and converted, two-stage filtering is performed on the analog signals, the analog signals are amplified to 0-5V by an instrument amplifier, and then the analog signals are converted into digital voltage sequences by a 16-bit ADC; the effective value, peak value and other parameters of the alternating-current power supply, the average value, ripple coefficient and other parameters of the direct-current power supply are calculated; the characteristic parameters are compared with preset threshold values, and if the characteristic parameters exceed the threshold values, it is determined that an abnormality occurs and relevant information is recorded; the detection results are transmitted to a monitoring terminal through RS485, data is stored locally, and when an abnormality occurs, an output switch quantity is output to an alarm device. The application is adapted to aviation power supply load fluctuation and environmental temperature change, has high detection precision, safe data transmission and storage, can accurately identify an abnormality and give an early warning, and improves the reliability and efficiency of aviation power supply operation and maintenance.

This invention provides an electrocardiogram (ECG) instrument amplifier circuit and an ECG signal acquisition system. In the ECG instrument amplifier circuit provided by this invention, a first terminal of a first capacitor scaling circuit is connected to the first output terminal of the instrument amplifier; a second terminal of the first capacitor scaling circuit is connected to the first terminal of a first neutralizing capacitor array; the second terminal of the first neutralizing capacitor array is connected to the first terminal of a first switch; and the second terminal of the first switch is connected to the first input terminal of the instrument amplifier. A second capacitor scaling circuit has its first terminal connected to the second output terminal of the instrument amplifier; its second terminal is connected to the first terminal of a second neutralizing capacitor array; the second terminal of the second neutralizing capacitor array is connected to the first terminal of a second switch; and the second terminal of the second switch is connected to the second input terminal of the instrument amplifier. A parasitic capacitance calibration circuit is connected to both the first and second input terminals of the instrument amplifier. This ECG instrument amplifier circuit can significantly improve the input impedance of the instrument amplifier.