DIGITAL STRAIN-GAGE TRANSDUCER ON CARRIER FREQUENCY

摘要

FIELD: measuring equipment.;SUBSTANCE: invention relates to measurement equipment and industrial electronics and serves to measure deformations, forces, pressures and other physical values by means of strain-gauge pickups assembled in measuring bridge. Disclosed is a digital strain-gage transducer on a carrier frequency, controlled from a computer through a system backbone, a command decoder and a programmable sine generator of the carrier frequency comprising a measuring bridge, generator output voltage level switch, generator voltage power amplifier for measuring bridge supply, sinusoidal generator to rectangular converter to control synchronous detectors of converter, preliminary instrumental amplifier of bearing frequency of measured signal, rejection filter 50 Hz, carrier frequency amplifier with programmable amplification factor, synchronous detector of measured signal with switchable transmission coefficient, low-pass filter with programmed cutoff frequency, buffer precision amplifier with differential output, two-channel analogue-digital sigma-delta converter with differential inputs, buffer amplifiers in reverse feed circuit of measuring bridge, calibration signal generator from measuring bridge supply voltage, synchronous power supply detector of measuring bridge, low-frequency filter of supply voltage of measuring bridge, buffer precision amplifier, which generates reference voltage of sigma-delta ADC (ratiometric measurement circuit), device for selection of operating mode of converter. Compensation of phase shift of signal in measuring channel, which occurs due to influence of reactive parameters of cables connecting measuring bridge with transducer and introducing error into result of measurement, is carried out using device that generates time shifts of control signals of synchronous detectors, realized in microchip of programmable logic.;EFFECT: high resolution of the converter, high accuracy of measuring static and low-frequency dynamic signals, simplifying the electrical circuit, reducing overall dimensions, realizing the structure in the form of a module in the international standard PXI (3U).;1 cl, 1 dwg