167 results about "Digital potentiometer" patented technology

The invention relates to the technical field of voltage acquisition, in particular to a battery string voltage acquisition system with a calibration system and a voltage acquisition method. Which comprises a multi-path voltage input end, a voltage signal adjusting end, a voltage follower, an analog-to-digital converter, a main control center and a communication circuit, and is characterized in that the voltage signal adjusting end comprises a dynamic voltage division network, consists of a digital potentiometer and a high-voltage operational amplifier, and dynamically adjusts the voltage division ratio to suppress common-mode voltage; the main control center is integrated with a multi-channel synchronous sampling calibration module and generates a global synchronous signal through the main MCU to control the ADC to perform synchronous acquisition; a temperature compensation module is arranged between the voltage follower and the ADC, and a digital temperature sensor is adopted to correct the gain drift of the operational amplifier in real time; the voltage division ratio of the dynamic voltage division network is dynamically adjusted according to the real-time common-mode voltage and a preset safety threshold value. According to the scheme, dynamic partial pressure adjustment, multi-channel self-calibration, nonlinear temperature compensation and a rapid protection mechanism can be integrated.

The invention belongs to the technical field of electrical safety, and particularly discloses an insulation resistance intelligent detection system and method for an energy storage converter, and the system is based on a bridge balance structure, integrates a temperature and humidity sensor and a voltage sensor, and collects environment parameters and bridge unbalance signals in real time. A digital potentiometer and a resistor array are driven through a PID algorithm to dynamically adjust bridge balance, and environmental interference is eliminated in combination with a temperature and humidity compensation model; and carrying out intelligent analysis on the preprocessed multi-dimensional data by utilizing a band-pass filtering and detection model, and outputting a high-precision insulation resistance value. The method achieves full-automatic detection, is high in precision, is quick in response, is suitable for complex working conditions, and remarkably improves the reliability of the insulation performance evaluation of the energy storage converter.

The invention particularly relates to a noise suppression test method and device for a vehicle-mounted chip, electronic equipment and a medium, and the method comprises the steps: correspondingly generating a noise waveform and a to-be-tested noise signal based on each piece of noise information of a vehicle, simulating a real noise signal of the vehicle based on the to-be-tested noise signal, and obtaining a target noise signal, the target noise signal is injected into the vehicle-mounted chip data link, the error code state of the vehicle-mounted chip data link is recognized, if no error code exists in the vehicle-mounted chip data link, the resistance value of the digital potentiometer is adjusted, the initial resistance value of the digital potentiometer is reset, and the step of injecting the target noise signal into the vehicle-mounted chip data link through the noise injection module continues to be executed; and generating a noise suppression test result of the vehicle-mounted chip until error codes exist in the data link of the vehicle-mounted chip. Therefore, the problem that the inhibition capability of the SerDes chip in the ultimate noise environment cannot be accurately evaluated due to the fact that complex noise interference in a real vehicle-mounted environment cannot be comprehensively simulated is solved.

The invention relates to the technical field of sensors, in particular to a rigid-flexible coupling rotating body deformation sensor based on full-flexible design and a testing method. The sensor comprises an annular main body; the annular main body is a closed ring formed by alternately connecting a plurality of rigid arcs and a plurality of flexible arcs; the rigid arc and the flexible arc are arranged in a manner of meeting dynamic balance; the plurality of micro data acquisition devices are respectively integrated on each rigid arc; the miniature data acquisition device comprises a Wheatstone bridge, a filtering module, a digital potentiometer, an analog-to-digital conversion module, a digital acquisition module, a single-chip microcomputer, a wireless signal sending module and a battery unit. The plurality of strain gauge groups are respectively arranged on the outer surface of each flexible arc; and the thickness of the flexible arc is uniform. According to the invention, deformation adaptation and high-sensitivity measurement are realized through a rigid-flexible arc alternating structure, and convenient monitoring under a rotation working condition is realized through a wireless communication miniature data acquisition device.

The invention discloses a control circuit and method for preventing battery heating from being out of control and a storage medium. One end of the control circuit is connected with the positive electrode of a battery, and the other end of the control circuit is sequentially connected with a main relay, a controllable fuse, a heating relay, a digital potentiometer, a heating film and a diverter in series to be connected to the negative electrode of the battery; the battery management system BMS is connected with the temperature sensing array, the main relay, the controllable fuse, the heating relay, the digital potentiometer and the shunt; the temperature sensing array is arranged near the battery; the battery management system BMS is set to control the main relay and the heating relay to be closed and control the circuit to be switched on; when the battery temperature reaches a threshold value, the digital potentiometer is controlled to increase the resistance value, so that the heating film reaches the safe heating power density; or the heating relay and / or the main relay are / is controlled to be switched off; or the controllable fuse is controlled to be fused; according to the invention, through dynamic threshold grading protection, multi-parameter collaborative fusing and distributed temperature sensing technologies, rapid blocking of abnormal temperature rise and active prevention of thermal runaway can be realized.

The control method comprises a control unit and a processing unit, the control unit comprises a plurality of resistors, a plurality of operational amplifiers, a digital potentiometer, a trigger, a counter and a phase inverter, one end of a resistor R15 in the plurality of resistors is connected with a CS pin and a 11 end of a digital potentiometer U8, and the other end of the resistor R15 in the plurality of resistors is connected with the other end of the digital potentiometer U8; 11, inputting a low-level signal during valve control; a U / D pin of a digital potentiometer U8 is connected with one end of a resistor R12 and an output pin of a phase inverter U7, an A1 pin is connected with a power supply, and a W1 pin, a B1 pin, one end of a resistor R13, a reverse end of an operational amplifier U11 and an in-phase end of an operational amplifier U10 are connected; the inverting end of the operational amplifier U10 is connected with a reference voltage end 21; the in-phase end of the operational amplifier U11 is connected with the reference voltage end 22; and the output ends of the operational amplifier U10 and the operational amplifier U11 are connected with a 1CLK pin of the trigger U9 and a CP pin of the counter U5.

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 belongs to the technical field of integrated circuits, and particularly discloses a numerical control programmable gain amplifier chip, which adopts an SIP (Session Initiation Protocol) packaged operational amplifier, a digital potentiometer, an input end Vin and an output end Vout, and is characterized in that an alternating current signal is input from the Vin end and is connected to an inverted input end of the operational amplifier through a capacitor C1 and an input resistor R1; a positive power supply pin of the operational amplifier is connected with a power supply positive electrode VDD, a negative power supply pin is grounded, and a VDD / 2 direct current bias voltage is obtained by an in-phase input end through a precision resistance voltage dividing network and is accessed after low-pass filtering; the high end of the digital potentiometer is connected with the Vout end, the low end is connected with the inverting input end of the operational amplifier, and a feedback path is formed through a sliding end. The digital potentiometer and the operational amplifier are integrated, high integration and modularization of the programmable gain amplification circuit are achieved, and the problems that in a traditional discrete scheme, due to analog switch conduction resistance, gain precision is insufficient, reliability of a multi-element system is lowered, and the circuit size is large are solved.

The invention discloses a driving circuit of a tunable laser, which comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a tenth resistor, a first operational amplifier, a second operational amplifier, a third digital potentiometer, a fourth operational amplifier, a first triode and a first voltage stabilizing diode, one end of the first resistor and one end of the fourth resistor are connected with a power supply, the other end of the first resistor is connected with the cathode of the first voltage stabilizing diode and the in-phase end of the second operational amplifier, and the anti-phase end of the second operational amplifier is connected with one end of the second resistor and one end of the third resistor. The output end of the second operational amplifier is connected with the other end of the second resistor and the anti-phase end of the first operational amplifier, the output end of the first operational amplifier is connected with one end of the tenth resistor and a second pin of the third digital potentiometer, and a seventh pin of the third digital potentiometer is connected with one end of the fifth resistor.

The invention provides a power supply regulating device and a voltage-adjustable power supply circuit thereof, and relates to the technical field of power supply regulation, the circuit is additionally provided with a sampling resistor, an operational amplifier unit and an MCU on the basis of keeping the original sampling partial voltage, and adjustable analog level output by the MCU is injected into a DC-DC feedback pin after being subjected to operational amplifier gain, so that the voltage-adjustable power supply circuit is formed. The potential of a feedback node is biased in a voltage superposition mode, so that the output voltage and the analog level are in an approximately linear relation; according to the invention, higher resolution adjustment can be obtained in a preset full range only by changing the DAC level or the PWM duty ratio, the gear intervals are uniform, digital potentiometers or segmented switching are not needed, the calculation is simple, the hardware cost is low, and the control is convenient. The high-precision power supply can be widely applied to occasions requiring a software controllable high-precision power supply, such as a thermal printing head test fixture, ink-jet head ink quantity control, motor torque adjustment and the like. The invention aims to solve the problems that the resolution of a low-voltage section is suddenly reduced and the fineness is insufficient due to resistance-voltage nonlinearity during wide-range voltage regulation of a traditional digital potentiometer type DC-DC feedback network.

The invention discloses an integrated multi-mode transcranial electrical stimulation and high-intensity deep brain stimulation device, and belongs to the field of neuromedical treatment, in the device, a main control module is used for receiving data sent by a serial port display screen communication module and processing and analyzing the data, and then a signal source module is driven to output a target signal; the signal source module selectively outputs a transcranial alternating current stimulation waveform, a time intervention electrical stimulation waveform, a high-current phase modulation time intervention electrical stimulation waveform, a transcranial pulse electrical stimulation waveform and a transcranial direct current stimulation waveform based on a plurality of waveform generators and digital potentiometers; and the signal amplification and constant current output module is used for amplifying the waveform voltage signal output by the signal source module, converting the waveform voltage signal into a constant current signal and outputting the constant current signal to the output module. According to the invention, the electric field intensity generated by the stimulation current at the deep brain target spot is improved, so that the deep brain region is effectively stimulated, and a more remarkable stimulation intervention effect is achieved.

The invention provides a wide dynamic range methane detection system based on synchronous accumulation and system reconstruction. The device is characterized by comprising a modulated laser (1), a gas absorption cell (2), a photoelectric detector (APD) (3), a variable gain trans-impedance amplifier (TIA) (4) based on a digital potentiometer, a dual-threshold voltage comparator circuit (5) and a microcontroller processing unit (6). The device can be used for large-dynamic-range real-time monitoring of the methane gas concentration, and the problem that a traditional TDLAS system is prone to saturation or limited in detection limit when the concentration span is large is effectively solved. The method can be widely applied to the fields of gas concentration detection, industrial safety control and the like.

The utility model belongs to the technical field of analog resistors, and particularly relates to a closed-loop feedback type analog resistor output circuit which comprises a micro-control unit. A sampling resistor; the programmable differential gain amplifier is connected with the sampling resistor and the micro-control unit; the digital-to-analog converter is respectively connected with the programmable differential gain amplifier and the micro-control unit; and the digital potentiometer is connected with the digital-to-analog converter. The micro-control unit monitors and controls each part, continuously digitally adjusts the gain of the programmable differential gain amplifier, the D value of the digital-to-analog converter, the digital voltage division ratio of the digital potentiometer and other parameters, and continuously optimizes the whole analog resistance output process according to feedback signals. Therefore, the highest precision of the analog resistor is ensured to reach 0.01%.

The nanosecond narrow pulse circuit comprises a nanosecond narrow pulse signal generation circuit and a signal driving enhancement circuit, an external trigger signal respectively passes through a first buffer and a second buffer of the nanosecond narrow pulse signal generation circuit to obtain two paths of same signals, a second resistor of the second RC time delay circuit is a digital potentiometer, the pulse width of signals can be set by changing the resistance value of the digital potentiometer, narrow pulse signals are obtained after two paths of same signals pass through a first AND gate, and narrow pulse signals with opposite phases and high driving capacity are obtained after the narrow pulse signals are input into a gate driving chip. And when the signal output by the gate driving chip is low level, the bias voltage, the current-limiting resistor and the light emitting diode form a current loop through the gate driving chip, and the light emitting diode is excited to emit light. The technical problems that an existing scheme for achieving a second narrow pulse laser is high in cost, difficult to be suitable for batch production and low in reliability are solved.

A Peripheral Nerve Stimulation (PNS) system and method are disclosed. The system includes a headset with ear hooks and electrodes for placement on the mastoid processes. A stimulation device connected to the headset via lead wires delivers a pulsed electrical current to the electrodes. The device communicates with a computing device equipped with a mobile application that controls the stimulation characteristics. The mobile application allows users to adjust settings, monitor progress, and access treatment sessions. The system also includes snap ports for electrode attachment, self-adhesive hydrogel electrodes, and current control mechanisms using a digital potentiometer and waveform generator. The method includes pre- and post-session anxiety rating, personalized treatment based on user inputs, and tracking of physiological biomarkers. The application supports multiple operating systems, secure cloud data storage, and enables data sharing with healthcare providers. The invention provides a comprehensive, customizable, safe solution for managing anxiety and insomnia.

The invention discloses a charging and discharging control circuit for independently controlling a battery and a system thereof, and relates to the technical field of battery charging, the control circuit adopts an independent control mode to carry out closed-loop regulation on the charging current of a BAT, and the problems of aging difference, capacity fading and the like caused by consumption of the cycle index of the battery are avoided; the control efficiency can be optimized according to charging time constants of different battery parameters, the adaptation range can be expanded, the control circuit comprises a control unit, the control unit comprises a plurality of operational amplifiers, a plurality of resistors, a plurality of digital potentiometers, a field effect transistor and a phase inverter, and the in-phase end of an operational amplifier U1 in the operational amplifiers is connected with a third pin of the digital potentiometer U2 and one end of a resistor R3; the anti-phase end is connected with one end of the resistor R2 and one end of the resistor R5, and the output end is connected with one end of the resistor R4; the in-phase end of the operational amplifier U4 is connected with the Vin1 end, the anti-phase end of the operational amplifier U4 is connected with the fifth pin and the sixth pin of the digital potentiometer U3 and the third pin of the digital potentiometer U6, and the output end of the operational amplifier U4 is connected with the second pin of the digital potentiometer U3, the input end of the inverter U5 and the P1 end.

This invention relates to a drive control circuit, its control method, medium, and switching circuit. The control method includes: controlling a power switch to start in an adaptive starting current identification mode; monitoring the starting current of the power switch; determining whether the starting current is within a preset range; and if not, adjusting the resistance of a digital potentiometer to bring the starting current within the preset range. This invention enables the automatic adjustment of the conduction speed of the power devices in the switching circuit based on the state of the downstream power circuit, thereby controlling the circuit's starting current and ensuring safe circuit startup.

The invention provides an over-acceleration protection system of an electric motorcycle. A Hall rotating handle outputs an operation control signal to a vehicle-mounted controller and a first input end of a comparison control circuit; the output end of the speed sensor is connected to the second input end of the comparison control circuit; the power input ends of the first electronic switch and the second electronic switch are connected to the power output end of the motor driving circuit, the power input end of the first electronic switch is connected to the power end of the driving motor, and the power output end of the second electronic switch is connected to the input end of the digital potentiometer. The output end of the digital potentiometer is connected to the power supply end of the driving motor, and the control end of the digital potentiometer is connected to the vehicle-mounted controller; the control input end of the first control circuit is connected to the first control output end of the comparison control circuit, and the first control circuit is used for controlling the on-off of the first electronic switch; the control input end of the second control circuit is connected to the second control output end of the comparison control circuit, the control output end of the second control circuit is used for controlling the on-off of the second electronic switch, and the second control circuit is also used for controlling the on-off of the first electronic switch when the second electronic switch is conducted.

The application relates to a self-enclosed self-adaptive amplitude equalizer. The equalizer comprises an equalization circuit, a tuning branch one and a tuning branch two adopting an electric tuning topological structure, the resistance values of the tuning branch one and the tuning branch two are adjusted to realize continuous slope adjustment of-10 dB to +10 dB in a 300 MHz to 1200 MHz frequency band; a main transmission circuit, an input end RFin and an output end RFout of which are respectively used as an input end and an output end of the equalizer; and the outputs of the tuning branch one and the tuning branch two are connected to a fusion node A on the main transmission circuit; a data acquisition and operation circuit, temperature and amplitude-frequency response data are collected in real time through an MCU microcontroller, and a pre-stored temperature-frequency-compensation lookup table and an aging model are combined to calculate a compensation control signal. The equalization circuit slope is adjusted through SPI control of a digital potentiometer and a varactor, and closed-loop self-correction is realized without manual intervention.

The utility model discloses an intelligent vibration switch circuit, which belongs to the technical field of switch circuits and is characterized in that electronic components adopt a filtering mode and a low-pass and high-pass mode to meet the gain in a wide frequency band range; according to the utility model, the digital potentiometer is adopted to control the gain, so that automatic switching of control channels is realized; a second digital potentiometer is adopted to automatically adjust the change of the phase to obtain the optimal phase; according to the utility model, by reducing the variety of the electronic module, the applicability of the electronic module is improved, and the intelligence of the electronic module is improved; the application applicability of the whole machine is improved; through self-diagnosis, the reliability of the instrument can be conveniently judged, the service life is prolonged, and the production efficiency of products and the rapidness and convenience of automatic maintenance in application are improved.

This utility model provides a high-performance power board, including a power input, a filter circuit, a surge protection circuit, a power conversion module, and a power output module. The power conversion module includes a full-bridge switching circuit and a transformer. The power conversion module has multiple independent outputs. A digital potentiometer is connected to the voltage regulation module of each independent output of the power conversion module, and the value of each independent output of the power conversion module is adjusted based on circuit feedback. This utility model device has the advantages of small size, high stability, and multi-channel adjustable output.

The application belongs to the technical field of integrated circuits, and specifically discloses a digital control programmable gain amplifier chip, which adopts an SIP packaged operational amplifier, a digital potentiometer, an input end Vin and an output end Vout, an alternating current signal is input from the Vin end, is connected to the inverting input end of the operational amplifier through a capacitor C1 and an input resistor R1, a positive power supply pin of the operational amplifier is connected to a positive electrode VDD of a power supply, a negative power supply pin is connected to the ground, a same-phase input end obtains a VDD / 2 direct current bias voltage through a precision resistor voltage dividing network and is connected after low-pass filtering, a high end of the digital potentiometer is connected to the Vout end, a low end is connected to the inverting input end of the operational amplifier, and a feedback path is formed through a sliding end. The operational amplifier and the digital potentiometer are integrated, high integration and modularization of the programmable gain amplification circuit are realized, and the problems of insufficient gain precision, decreased reliability of a multi-element system and large circuit volume caused by the on-resistance of an analog switch in a traditional discrete scheme are solved.

The invention discloses a smog methane composite detection method and device, relates to the technical field of smog methane detection, and solves the technical problems of weak anti-interference capability in a data processing link and lack of a multi-parameter compensation and calibration system. The effective acquisition range is dynamically calculated in combination with a factory calibration interval, the signal amplification factor is adaptively adjusted by using a digital potentiometer, the electric signal strength is ensured to be stabilized in the optimal interval, the influence of laser loss and environment temperature on basic data is eliminated from the source, and the filtering coefficient is dynamically adjusted in combination with the signal-to-noise ratio by using a layered filtering strategy. Random noise is filtered out, and key features of an absorption peak are reserved; through segmented weighted polynomial fitting, accurate extraction of core parameters of the absorption peak is realized; and a unified multi-round outlier elimination mechanism eliminates the interference of abnormal data on the methane concentration, the absorption peak position and the smoke sensing value, and improves the credibility of the data.

The invention relates to a damaged wire detection method, device and system suitable for automatic wire stripping equipment and an embedded program product. The system comprises a signal acquisition module, a frequency conversion module, a digital adjustment module, a phase lock processing module, a signal output module, a buffer amplification module, a master control algorithm module, an anti-interference module and other functional modules. Through a signal acquisition unit formed by an SMA coaxial connector, an EMC protection network and a current-limiting resistor, high-sensitivity detection of capacitance change between a wire core and a cutter in a cable stripping process is realized. The RC inverting oscillator and the digital potentiometer bridge network realize frequency conversion, the phase-locked loop and the low-pass filter are combined to output an analog voltage signal, and the main control unit performs real-time threshold judgment and abnormity identification based on the signal. The system supports multi-channel detection and full-process data archiving, has the advantages of high detection sensitivity, strong anti-interference capability, adaptability to automatic high-speed takt and the like, and can realize real-time, lossless and high-reliability monitoring of cable stripping and damage in a complex industrial environment.

The utility model discloses a program-controlled frequency sweep signal source circuit, which comprises a sawtooth wave generator, a digital potentiometer, an MCU (Microprogrammed Control Unit) control circuit and a DAC (Digital-to-Analog Converter) circuit. The output end of the MCU control circuit is respectively connected with the input ends of the sawtooth wave generator, the digital potentiometer and the DAC circuit; the input end of the sawtooth wave generator is connected with the MCU control circuit, and the output end of the sawtooth wave generator is connected with the digital potentiometer; the input end of the digital potentiometer is respectively connected with the sawtooth wave generator and the MCU control circuit; the input end of the DAC circuit is connected with the output end of the MCU control circuit. The MCU control circuit can efficiently process parameters such as frequency sweep signal source bandwidth, frequency sweep frequency and central frequency point input from the outside and convert the parameters into internal control signals, and the highly integrated design simplifies the circuit structure and improves the reliability and stability of the system.

The invention discloses a modulatable and bipolar high-voltage square wave generating circuit, which comprises a power supply unit, a low-voltage square wave generating unit, a high-voltage amplifying unit, an adjusting unit and an MCU (Microprogrammed Control Unit), the power supply unit comprises a low-voltage unit and a high-voltage unit, the low-voltage square wave generating unit comprises a grid driving chip U6, an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) Q1 and an MOSFET Q2, the high-voltage amplifying unit comprises an operational amplifier U1, and the high-voltage amplifying unit comprises a high-voltage amplifying unit, an adjusting unit and an MCU (Microprogrammed Control Unit). The power supply of the operational amplifier U1 is connected with the high-voltage unit, the input signal of the high-voltage amplifying unit is connected with the low-voltage square wave generating unit, the adjusting unit comprises a digital potentiometer U10, the adjusting unit is connected with the MCU unit, and the MCU unit is connected with the power supply unit, and is connected with and controls the input level of the gate driving chip U6. The amplitude and the frequency of a low-voltage square wave signal are adjusted through the gate driving chip U6 and the digital potentiometer U10, and then the amplitude and the frequency of a bipolar high-voltage square wave circuit are adjusted through the operational amplifier U1 in the high-voltage amplification unit, so that multi-voltage adjustment in the microfluidic liquid drop driving process is facilitated.

The present application relates to nuclear radiation detection technical field, provide a kind of nuclear measurement analog quantity transmission method based on feedback compensation circuit, the hardware part used by this method includes ARM chip, digital-analog converter, digital potentiometer, operational amplifier, isolated voltage current converter, isolation chip, A / D conversion chip, the ARM chip is connected with digital-analog converter, digital potentiometer respectively, the ARM chip is connected with A / D conversion chip after isolation chip, the first operational amplifier is connected with digital-analog converter, digital potentiometer, isolated voltage current converter respectively, the output current of isolated voltage current converter is connected with A / D conversion chip through precision resistance, second operational amplifier.The present application method can be promptly revised output current according to the comparison result of output signal and input signal, and the mode of feedback compensation is used to adjust input signal, improves output accuracy.

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.

An apparatus for characterizing a sample using nuclear quadrupole resonance (NQR) spectroscopy is described whereby a plurality of NQR detectors operate in tandem, whereby each NQR detector is optimized to operate within a designed frequency range, having the means to shuffle the sample from one NQR detector to the next such as an automatic sample changer, having the means of controlling the frequency and amplitude of the radiofrequency field generated by the NQR detector through motors controlling variable capacitors or through the use of varactor diodes, digital capacitors, or digital potentiometers, having a plurality of Zeeman modulation coils to create a magnetic field surrounding the sample which may be arranged to minimize stray fields, such as a toroid, having the means of operating the spectrometer in frequency modulation mode, and having the capability of configuring the device for either continuous-wave NQR or pulsed NQR.

The utility model discloses an operational amplifier power supply adjusting circuit comprising an operational amplifier tube which is provided with a power supply end and an output end; the first current converter is provided with an input end, an output end and a control end, the input end of the first current converter is coupled with a first power supply, and the output end of the first current converter is coupled with the power supply end of the operational amplifier tube; the first digital potentiometer is provided with a first end, a second end and a third end, the first end of the first digital potentiometer receives a first control signal, and the second end and the third end of the first digital potentiometer are both coupled to the control end of the first current converter. When the voltage difference between the power supply voltage of the operational amplifier tube and the voltage output by the operational amplifier tube is large, the difference between the power supply voltage and the voltage output by the operational amplifier tube can be reduced, the problem of overhigh temperature or temperature drift of the operational amplifier tube caused by overlarge voltage difference is avoided, the gain of the operational amplifier can be optimized, the signal-to-noise ratio and the sensitivity of the circuit are improved, and the reliability of the circuit is improved. And the service life of the circuit can be prolonged.