Shao Yunfeng

Bio: Shao Yunfeng is an academic researcher. The author has contributed to research in topics: Resistor & Operational amplifier. The author has an hindex of 2, co-authored 2 publications receiving 10 citations.

High-precision small resistor resistance measurement circuit

Abstract: The invention discloses a high-precision small resistor resistance measurement circuit. The circuit comprises a constant current source circuit, a single-terminal/difference operation amplification circuit, an A/D conversion processing circuit and a microprocessor control circuit. The constant current source circuit provides a constant micro current for a measured resistor and generates a millivolt-level measured voltage on the measured resistor. The single-terminal/difference operation amplification circuit amplifies the millivolt-level voltage to acquire the measured voltage after operation amplification. The A/D conversion processing circuit converts the measured voltage after operation amplification into a digital waveform so as to acquire the measured voltage of the digital waveform. The microprocessor control circuit carries out filtering processing on the measured voltage of the digital waveform, calculates and acquires a resistance of the measured resistor. In the technical scheme, measurement precision of the small resistor is increased.

Universal tester for testing fire work equipment

Abstract: The present invention discloses a universal tester for testing fire work equipment. The universal tester comprises a differential input operational amplifier unit, a signal acquisition unit, an electrical isolation unit, a microprocessor control unit, a relay matrix module, a man-machine interaction module and a constant-current source unit. The differential input operational amplifier unit is sequentially and electrically connected with the signal acquisition unit, the electrical isolation unit, the microprocessor control unit and the man-machine interaction module. The relay matrix module is respectively and electrically connected with the differential input operational amplifier unit and to-be-tested fire work equipment. The man-machine interaction module is connected with a remote control terminal through a wired network or a wireless network. The universal tester is provided with a 16-bit high-precision A/D converter, thus being high in data resolution and capable of effectively improving the small-resistance measurement accuracy of fire work equipment. The universal tester is also provided with a temperature-compensated high-precision constant-current source unit and is capable of supplying a stable and reliable safety current to the to-be-tested fire work equipment.

Precise tester for micro-resistor

Abstract: The invention discloses a precise tester for a micro-resistor. The precise tester comprises a data processing module, a data acquisition module and a micro-resistor test module. The micro-resistor test module comprises a constant current source circuit and a signal amplification circuit which are connected with the micro-resistor Rx to be tested. The constant current source circuit is used for applying constant current to the micro-resistor Rx to be tested. The data acquisition module acquires and processes the amplified voltage signal. The data processing module calculates the resistance value of the micro-resistor according to the constant current value and the acquired voltage value. The constant current source circuit comprises a constant current source Is and a clamp resistor Rc whichis connected in parallel with the micro-resistor Rx to be tested. The constant current source Is is used for applying constant current which is not greater than the current threshold to the micro-resistor Rx. The clamp resistor Rc clamps the voltage Ux of the micro-resistor Rx to be lower than the voltage threshold so that the measurement error caused by excessively high output voltage can be avoided. The precise tester for the micro-resistor has high test accuracy, multiple measurable channels, high degree of test automation and fast measurement speed so as to be particularly suitable for batch test of the micro-resistor.

Cable network conduction test method based on constant current source

Abstract: The invention provides a cable network conduction test method based on a constant current source. The constant current source is used as the power supply of the cable network conduction test. The group test method is used in the cable network automatic test to perform quick testing between any two points in the network so as to realize the automatic test function of cable network conduction. The equipment uses a constant current module, a sampling module, a relay array and a test module with combination of automatic control of software so as to realize the test function of the network relationamong all the endpoints of the cable network. Implementation is convenient, the automatic test efficiency of the cable network can be enhanced and the present blank of the related domains in China can be filled.

Initiating explosive device resistance test device and initiating explosive device resistance test method

Abstract: The invention discloses an initiating explosive device resistance test device and an initiating explosive device resistance test method. The device comprises a control module, a DAC module, a voltageloss compensation module, an excitation signal generation module and a test signal generation module, wherein the control module sends at least a digital signal to the DAC module according to the signal of an FPGA module; the digital signal is used to transmit the parameters of an excitation signal and a test signal; the DAC module converts the digital signal into a first simulation signal and sends to the excitation signal generation module, and the excitation signal generation module converts the first simulation signal into a test current; the DAC module also converts the digital signal into a second simulation signal, and sends to the test signal generation module, and the test signal generation module converts the second simulation signal into a test voltage; the voltage loss compensation module is used for carrying out loss compensation on the returned test signal; the excitation signal generation module inlcudes a constant current feedback circuit for maintaining the stability of an output current; and the test signal generation module includes a clamp protection circuit and an ADC measurement circuit.

High-precision resistor measurement system and method based on combination of differential method and proportional method

Abstract: Disclosed are a high-precision resistor measurement system and method based on the combination of a differential method and a proportional method. The system comprises: a constant-current source, a reference resistor, a first differential amplifier, a programmable gain amplifier, an analog-to-digital converter, a microprocessor, a digital-to-analog converter and a measured resistor interface, wherein a measured resistor is connected to the measured resistor interface; the reference resistor and the measured resistor are connected in series to form a series branch that is connected between the constant-current source and the ground; two input ends of the first differential amplifier are respectively connected to two ends of the reference resistor, and an output end thereof is connected to a voltage reference end of the analog-to-digital converter; and a first input end of the programmable gain amplifier is used for being connected to a ground single-ended voltage of the measured resistor, a second input end thereof is connected to an analog output end of the digital-to-analog converter or the ground in a controlled manner, an output end thereof is connected to an analog input end of the analog-to-digital converter, and digital output ends of the analog-to-digital converter and the digital-to-analog converter are both connected to the microprocessor. By means of the system of the present invention, the influence of power supply fluctuations can be overcome, and the system has a low cost and a high measurement precision.

Test method for protective resistance

Abstract: The invention discloses a test method for a protective resistance. The device for the protective resistance is used for testing; constant current is output by a constant current source module in a device for the protective resistance, input to a test equipment interface through a relay switch circuit, and output to the protective resistance under test through a test cable; the voltage drop generated by the protective resistance under test is output through a product end interface, transmitted to an amplifying circuit through the test cable and the relay switch circuit, and conveyed to an AD acquisition module after being amplified by the amplifying module; an embedded computer system is used for calculating the protective resistance under test according to the calculation formula of the protective resistance under test; and when the measuring result of the protective resistance under test does not exceed an error, deviation is not required. The problem of instability in a traditional test measure is solved effectively; the test result of the test equipment researched by the automatic test method for the protective resistance is stable and accurate; and the influence of the measuring error of the test equipment on the judgement of production and test result is avoided.