SU1711199A1 - Exponential converter - Google Patents

Abstract

The invention relates to automation and computer technology and can be used in differential pressure measurement transducers — differential pressure gauges. The purpose of the invention is to expand the scope. The power converter contains alternating current generator 1, 2 displacement transformer converter, half-wave rectifiers 3, 4, switches 5-8, memory capacitors 9-11, buffer amplifiers 12, 13, adder 14, differential amplifier 15, integrators 16, 17 with reset, analog-to-digital converter 18 push-pull integration, stable voltage source 19, element NOT 20, voltage converter 21 — current. The device reduces the influence of the instability of the alternator 1 on the conversion accuracy. 1 il. Ё b //. F o y

Description

The invention relates to automation and computer technology and can be used in differential pressure transducers — differential pressure gauges used in variable pressure drop flow meters, where the function of square root extraction and normalization of the output signal for communication with centralized control devices are necessary.

The purpose of the invention is to expand the scope.

The drawing shows a functional diagram of the proposed Converter.

The power converter contains an alternating current generator 1, a transformer converter 2 movements, the first 3 and second 4 half-wave rectifiers, the first 5, the second b, the third 7 and the fourth 8 keys, the first 9, the second 10 and the third 11 storage capacitors, the first 12 and the second 13 buffer amplifiers, adder 14, differential amplifier 15 first 16 and second 17 integrators with reset, analog-to-digital converter 18 (ADC) push-pull integration, stable voltage source 19, HE element 20 and voltage converter 21 - t OK.

The Converter operates as follows.

In the first phase of the impulse conversion cycle. So, from the output of the autocorrection zero drift signal, the ADC 18 opens keys 7 and 8 and the storage capacitors 10 and 11 are charged through rectifiers 3 and 4 by voltages from the first and second outputs of transformer converter 2, respectively. The voltage amplitude of the transformer converter 2 increases as the plunger moves at the first output and falls at the second output. Accordingly, the voltage on the second storage capacitor 1 rises (Y, and on the third storage capacitor, capacitor 11 drops. The primary winding of the transformer converter 2 is powered by an unstabilized alternating current generator 1. The voltage from the second 10 and third 11 storage capacitors through buffer amplifiers 12 and 13 are respectively supplied to the inputs of the differential amplifier 15, at the output of which an input voltage of their ADC 18 is formed, proportional to the voltage difference between the first and second outputs of the transformer. The transducer 2 is fed to the input of the adder 14, the output of which forms the reference Uon voltage proportional to the sum of the voltages of the transformer converter 2. This reduces the influence of the amplitude instability of the generator 1 and the dependence of the transfer coefficient of the transformer converter 2 on the conversion accuracy, so as a change in any of the voltages on the second 10 or third 11 storage capacitor leads to a similar change in the voltages Ux and Uon.

In the second phase of the conversion cycle, during the time T, the voltage Ux from the output of the differential amplifier 15 is fed to the information input of the ADC 18.

The voltage Ux is integrated by the integrator of the ADC 18.

In the third phase of the conversion cycle of tx duration, the tx signal from the output of the HE element 20 connected to the pulse output of the ADC 18 is fed to the reset input of the second integrator 17. The voltage Uon from the output of the adder 14 is integrated by the integrator 17, and simultaneously the voltage Uoi from the integrator output 17 (by

polarity reverse Ux) is applied to the input of the reference voltage of the ADC 18. The integrator of the ADC 18 is discharged until the end of the phase equal to

tx-kiVUT, (1)

where Ki 2n T / Uon is a constant coefficient;

TI is the integrator integration constant 17,

which corresponds to the square root of the voltage difference across the storage capacitors 10 and 11.

The tx signal opens the first switch 5 and the voltage UCT from the output of the stable voltage source 19 is fed to the input of the first integrator 16, the output voltage of which rises to level taking into account relationship (1)

Uo2 UcT-tx / r2, (2)

where ng is the integration integrator constant 16;

 K2 is a constant coefficient.

The voltage Uo2 charges during the time T.A.K (the second key 6 is closed the first storage capacitor 9, and during the time T the output signal of the initial conditions setting of the ADC 18 is fed to the reset input of the first integrator 16 and discharges the integrator capacitor 16. The voltage Uo2 is converted by converter 2.1 voltage - current to the output current of the power converter, proportional to the square root of the signal at the information input of the power converter (measured by the differential pressure AP).

An introduction to the converter is an alternating current generator 1, a transformer converter 2 movements, the first 3 and second 4 rectifiers, the third 7 and fourth 8 keys, the second. 10 and third 11 storage capacitors, first 12 and second 13 buffer amplifiers, adder 14, differential amplifier 15 of the second integrator with a reset, the NOT element 20 allows to expand the range of application of the converter and reduce the effect of instability of the alternator 1 on the conversion accuracy.

Claims (1)

Claims of the Invention A power converter containing a push-pull integrated analog-to-digital converter, the pulse output of which is the corresponding power converter output and connected to the control input of the first key, the drift zero auto-correction signal output is connected to the control key of the second key, and the output signal the initial conditions are set to the reset input of the first integrator, the output of a stable voltage source through the first key connected in series, the first integrato p, the second switch and the first voltage-current converter are connected to the current output of the power converter; the output of the second switch is connected via the first storage capacitor to the zero potential bus, characterized in that, in order to expand the field of application, two half-wave rectifiers are introduced into it, the third and fourth keys, the second and third storage capacitors, two buffer amplifiers, the element is NOT, the second an integrator, a differential amplifier, an alternator connected by an output to an electrical input of the primary power supply of a transformer displacement converter, and an adder connected by an output to an information input of a second integrator connected by an output to the input voltage of an analog-to-digital two-stroke integrated converter whose time output pulse connected through the element NOT to the reset input of the second integrator, and the information input is connected to the output of the differential preamplifier, the first and second inputs of which connected to the first and second inputs of the adder, connected to the outputs of the first and second buffer amplifiers, respectively; the first and second outputs of the transformer displacement transducer, whose mechanical input is the information input of the power converter, are connected via the first and second half-wave rectifiers to the information inputs of the third and third the fourth keys, the control inputs connected to the output signal of the auto-correction of the drift zero analog-digital converter two integrating stroke and outputs connected to the inputs, respectively, of the first and second buffer amplifiers, connected through the second and third memory capacitors, respectively, with a zero potential bus.