SU659989A1 - Complex resistance digital meter - Google Patents

Description

the logo-digital converter is connected to the memory block of another measuring channel, the adders are interconnected and the cf is connected to the voltage path, and the large-scale converters are connected to the sources of quadratic and quadrature sinusoidal voltages, respectively.

The drawing shows a structural electrical circuit diagram of the complex measuring instrument.

The digital impedance measuring device contains a source of polarizing 1 and in-phase sinusoidal 2 voltages connected to the inputs of the voltage-current converter 3, to the output of which the object under study 4 and voltage amplifier 5 is connected. The output of amplifier 5 of the interface is connected to the inputs of measuring channels 6 and 7, which consist of successively connected blocks 8 and 9 of memory, decoders 10 and 11, mass converters 12 and 13, adders 14 and 15, phase detectors 16 and 17, analogue digital converters 18 and 19 and reading devices 20 and 21. The inputs of the wide-scale converters 12 and 13 are connected respectively to sources of quadrature sinusoidal 22 and syphasic 2 and outlets. The inputs of the adders 14 and 15 are the inputs of the measuring channels 6 and 7. The outputs of the analog-digital converters 18 and 19 are connected respectively to the inputs of blocks 9 and 8 of the memory of the measuring channels 7 and 6.

The meter works as follows.

The signal inputs of the phase detectors 16 and 17 through the adders 14 and 15 and the voltage amplifier 5 and the alternating voltage of the object under study 4, equal to

ij U, K (ReZ +),

where - source voltage

2 common mode voltage;

  / (2, and / G are the transfer coefficients of the voltage-current converter 3 and the amplifier 5 and the voltage; Z is the value of the impedance of the object under study 4.

From the output of the phase detectors 16 and 17, the voltage, directly proportional, respectively, to the real and imaginary components of the complex resistance of the object under study 4, goes to analog-to-digital transformers 18 and 19, where they are converted into codes, which are fed to readout devices 20 and 21 and blocks 8 and 9 of memory, storing information about codes in the pauses between measurements. The signals of the units of us through the power of 10 and I control the transmission coefficients of the scale converters 12 and 13 so that in any of the measurement cycles their output voltages Vi and U are respectively

l-y / OL s - wad /, „2,

U, U, K ,,

where Lz and K are the transmission coefficients of the wide-scale converters 12 and 13.

After performing the summation operations, the output voltages of the adders 14 and 15 are equal to U + L / i and U + Uz, respectively, and do not contain measurable quadrature components, which excludes measurement errors.

This gauge, compared with the known gauges, improves accuracy and extends the range of measured impedances by more than an order of magnitude.

Claims (3)

Invention Formula A digital gauge of complex co-motions containing a source of quadrature sinusoidal voltage, voltage-current converter, the inputs of which are connected to sources of polarizing n in-phase sinusoidal voltages, and the output to the object under study and voltage amplifier, as well as two measuring channels each containing one phase detector and one readout device, characterized in that, in order to extend the range and increase the measurement accuracy, each The measuring channel is equipped with an analog-to-digital converter, a decoder, a large-scale converter, an adder and a memory unit connected through serially connected decoder, a large-scale converter, an adder, a phase detector and an analog-to-digital converter to the reading device, the analog-to-digital converter connected to the memory block of another the measuring channel, the adders are connected to each other and with the amplifier voltage, and the large-scale converters - respectively with the sources of in-phase and quadrature sinusoidal voltage. Sources of information irinigated into account and exertiz 1. US Patent N ° 3284705, cl. 324-57, published. 1965. 2. USSR author's certificate L 294109, cl. G 01R 19/06, 1969. 3. USSR author's certificate No. 451020, cl. G 01R 27/00, 1972.