SU1265624A1 - Automatic alternating current digital bridge - Google Patents

Abstract

This invention relates to measurements of parameters of complex resistances and can be used as a measurer of impedance parameters in a wide frequency range. Purpose . invention - increase measurement accuracy. The device contains voltage dividers 2 and 3, exemplary measures of capacitance 9 and active conductivity 10, equilibrium detector 11, automatic balancing unit 12 and clock generator 14, Introduction of A source (L

Description

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1 constant voltage, transform.

4, 5 and 6 DC to AC voltage and ring counter 13 with the formation of new connections between the elements of the device eliminates the additional frequency error. At the same time, the balancing elements of the bridge circuit retain the metrological characteristics in the entire operating frequency range, and the newly introduced ones do not introduce additional frequency errors up to a frequency of several hundred kilohertz. The accuracy of the device at a frequency of 100 kHz is practically not reduced compared with a frequency of 1 kHz. 1 il.

The invention relates to electrical measuring equipment, namely the measurement of parameters of complex resistances, and can be used as a measuring instrument for impedance parameters in a wide frequency range.

The purpose of the invention is to improve the measurement accuracy when operating in a wide frequency range by eliminating additional frequency error.

The drawing shows the functional diagram of the device.

The device contains a source of 1 constant voltage, dividers 2 and 3 voltage, key converters 4-6 constant voltage to alternating, clamps 7 and 8 for connecting the measurement object, exemplary capacitance "9" and active conductivity 10 j detector 11 equilibrium, an automatic balancing unit 12, a ring counter 13, a clock generator 14, the output of source 1 of a constant reference voltage connected to the input of the first voltage divider 2, and the output of the last connected to the input of the second voltage divider 3. The output of a constant voltage source is also connected to the input of the first key converter 4 of a constant voltage to an alternating voltage, and the outputs of the first and second voltage dividers are connected respectively to the inputs of the second and third key converters 5 and 6 of a constant voltage to an alternating voltage . The outputs of the first, second, and third DC / AC key converters are connected respectively to a clamp 7 for connecting one of the electrodes of the measurement object, the second

the electrode of which is connected to the second terminal 8 by exemplary measures of the capacitance 9 and active conductivity 10. A second terminal for connecting the measurement object, the second electrodes of the measures of active conductivity and capacitance are connected together and connected to the input of the equilibrium detector 1, the output of which is connected

with an input of the automatic balancing unit 12. The first output of the latter is connected to the control input of the first voltage divider, and the second to the control input of the second voltage divider.

The ring counter 13 is connected by the direct outputs of its flip-flops to the digital inputs of the first key converter, and the inverse outputs of the flip-flops to the digital inputs of the second and third key converters. The clock generator 14 is connected by the first output to the clock input of the automatic balancing unit 12, and by the second output to the input of the ring counter 13.

The device works as follows.

The DC voltages of the source 1 of the first 2 and second 3 dividers are respectively supplied to the inputs of the first 4, second 5, and third 6 DC / DC converters. With the help of the latter, variable stresses are formed. Moreover, the frequencies and phases of the output voltages of the second 5 and third 6 key converters are determined by the frequency, phase and frequency of the pulses at the inverse outputs of the ring counter 13 and are therefore the same as the frequency of the output voltage of the first converter 4

Claims (1)

Claim An automatic digital AC bridge containing an equilibrium detector, exemplary measures of active conductivity and capacitance, the first conclusions of which are connected to the input of the equilibrium detector, clamps for connecting the measurement object, the first of which is also connected to the input of the equilibrium detector, an automatic balancing unit, the input of which is connected to the output of the equilibrium detector, a clock generator, the first output of which is connected to the clock input / 5lock of automatic balancing, the color For voltage, the control inputs of which are connected to the outputs of the automatic balancing unit, characterized in that, in order to improve the measurement accuracy when working in a wide range by eliminating the additional frequency error, a constant voltage source, three key DC-to-AC converters are introduced into it, a ring counter, the input of which is connected to the second output of the clock generator, while the digital inputs of the first key DC-AC to AC converter e, connected to the lines, and the second and third - inverse to ring counter outputs, analog inputs of the first, second and third ". key DC-AC converters are connected respectively to the DC voltage source, the outputs of the first and second voltage dividers, and their outputs, respectively, to the second terminal for connecting the measurement object, the second output of the exemplary measure of capacitance and the second output of the exemplary measure of active conductivity, and the input of the first divider voltage is connected to a constant voltage source. ί