Patent RU-2698072-C1 (RU)
Title: Method of determining parameters of impedance of a two-terminal device and device for its implementation
Inventor: KIM VALERIJ LVOVICH
IPC: G01R27/02
Filed: 2018-12-24
Granted: 2019-08-21
Abstract: FIELD: measuring equipment. 
     SUBSTANCE: inventions relate to electric measuring equipment, namely to measurement of active, reactive and full impedance of a two-terminal device, and can be used for measurement of parameters of passive electric circuits. Method of determining parameters of impedance of a two-terminal device involves preliminary determination of the impedance of the two-terminal element to direct current and determination of the value of the impedance module at the measured frequency in the range of operating frequencies of the two-terminal device. When determining the active component of the two-terminal device with the capacitive component, the change in the output current of the controlled voltage-current converter is set to the value of the constant voltage across the two-terminal device, which is equal to the upper limit of measurement of the voltage at the input of the microcontroller. When determining the capacitance component by changing the frequency of the controlled analogue generator of sinusoidal voltages, the amplitude of the alternating voltage on the two-terminal device is two times less than the constant voltage. Determination of the active component of the two-terminal device with the inductive component is carried out by setting the output direct current equal to the upper limit of the working range of the controlled voltage-current converter flowing through the two-terminal device. Inductive component of the two-terminal device is determined at a frequency at which the amplitude of the alternating voltage on the two-terminal device is one and a half times greater than the constant voltage across it. Bipolar impedance parameters are determined using formulas. Device for determining parameters of impedance of a two-terminal device comprises first and second input terminals for connecting the measured impedance, synchronous detector, which input is connected to first input terminal, and output is connected to low-pass filter, first and second multiplexers, power supply, controlled generator of sinusoidal voltages, control input of which is connected to first output of microcontroller. Power supply output is connected to the first input of the second multiplexer. Output of the low-pass filter is connected to the first input of the microcontroller, the second, third and fourth outputs of which are connected to the input of the alphanumeric indicator. Output of the manual control panel is connected to the second input of the microcontroller. Output of the second multiplexer is connected to the control input of the synchronous detector. Control input of the first multiplexer is connected to the fifth output of the microcontroller. Input of the controlled voltage-to-current converter is connected to the output of the first multiplexer. First output of the controlled voltage-to-current converter is connected to the first input terminal. Second output of the controlled voltage-current converter is connected to the second input terminal and common wire of the device. First input of the first multiplexer is connected to the first input of the second multiplexer, the third input of which is connected to the output of cosinusoidal voltage of the controlled analogue generator of sinusoidal voltages. Second inputs of the first and second multiplexers are connected to the output of sinusoidal voltage of the controlled analogue generator of sinusoidal voltages. Control inputs of the second multiplexer are connected to the sixth and seventh outputs of the microcontroller. Control input of the controlled voltage-to-current converter is connected to the eighth output of the microcontroller. 
     EFFECT: simple method and device for determining parameters of impedance of a two-terminal device without loss of accuracy. 
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