SU1370460A1 - Voltage instrument transducer of variable relactance pickups - Google Patents

Abstract

The invention relates to electrical measuring equipment and serves to simplify the converter while maintaining the accuracy of the conversion. The converter contains sensor 1, power source 2, reference voltage source 3, and pulse shaper 4. The introduction of sampling-storage unit 5 and the execution of a pulse shaper 4 in the form of a comparator 6, AND-HE elements 7.9, resistors 10 and 11, and a capacitor acting as a detector and a compensator, simplify the converter circuit. Thus, conversion errors are reduced due to the influence of the voltage fluctuations of the power source 2 at a lower instrumental cost. This is especially important in multichannel information collection and processing systems. 2 Il. with (L

Description

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The invention relates to electrical measuring equipment, in particular, to voltage transducers of induction and transformer sensors.

The purpose of the invention is to simplify the converter while maintaining the accuracy of the conversion.

Fig, 1 shows a block diagram of the proposed Converter; Fig. 2 shows the time diagram of the converter operation.

The inductive sensor voltage transducer contains sensor 1, power source 2, reference voltage source 3 (ION), pulse driver 4 and sampling-storage unit 5 (BVH), and the power input of sensor 1 is connected to the first output of power source 2 The first output of which is connected to the first input is the pulse former 4, the second input of which is connected to the output of ION 3, and the output is connected to the control input of the sampling-storage unit 5, the second input of which is connected to the output of sensor 1, output BVH 5 is connected to the output of the mouth oystva.

The pulse shaper 4 contains a comparator 6, three IS-NE 7-9 elements, two resistors 10 and 11 and a capacitor 12, the first and second inputs of the pulse shaper 4 are connected respectively to the non-inverting and inverting inputs of the comparator 6, the output of which is connected to the first inputs elements AND-NOT 7 and 8 and with the first terminals of the resistors 10 and 11, the second output of the resistor 10 is connected to the potential + 5V, and the second output of the resistor 11 - to the second input of the element AND-NE 7 and through the capacitor 12 - to the common bus, output element AND- NOT 7 is connected to the second input of element AND- NOT 8, the output of which is connected to both inputs of the element AND-HE 9, the output of which is connected to the output of the driver 4 pulses.

As primary converters, DAT and DIT induction sensors, rotary transformers of the type 45V-32, 50D-32, 90D, etc. can be used, the main feature of which is the need to use a power source. As such a source, a generator is used that generates a sinusoidal voltage, to which no

The requirements are amplitude stability.

The pulse shaper 4 also contains a comparator, which serves to compensate for the effects of changes in the amplitude of the voltage of the power source 2, and a logic circuit containing three AND-NOT logic elements and an RC chain, which separates the pulse of a given duration on the shaper of the comparator 4 momentum. From the comparator output, pulses are received, the duration of which is proportional to the amplitude of the voltage of the power source 2 within a variation of, for example, ± 10% of the supply voltage.

Sampling-storage unit 5 is an integrated circuit of the type 1100 CC2.

The measuring transducer of the voltage induction sensors operates as follows.

The voltage of the power source 2 is supplied to the sensor 1 and to the non-inverting input of the comparator 6 of the pulse shaper 4, which converts it to rectangular pulses, the duration of which is proportional to the amplitude of the supply voltage.

The proportionality is due to the fact that the inverting input of the comparator 6 of the pulse shaper 4 receives a voltage Uon of such magnitude that the operation of the comparator 6 occurs in the initial linear portion of the sinusoidal voltage i.p. (Fig. 2), the angular frequency is in this case the limits

ABOUT ,

where to - angular frequency

supply voltage. In this area, the voltage is

UN. ,

where DO is the amplitude value of the power supply voltage; UPP is the direct current reference voltage.

Thus, the sampling moment is determined by the formula

, p / Uc ,.

The logic circuit consisting of three elements AND-NOT 7 - 9 and an RC circuit generates a pulse of a certain duration along the leading edge of the pulses, coming from the output of the comparator 6 of the driver 4 of the pulse (Fig. 2). These pulses control the operation of the VBO 5. The output voltage is then equal to

k and „

, kU, k.

F-U

where k is the transmission coefficient of sensor 1; F is pressure force;

k - coefficient of proportionality.

Thus, with a correctly chosen magnitude of the reference voltage depending on the voltage fluctuations of the power source, a measurement range can be obtained in which the effect of changes in U on Ug ,, is excluded.

Formation of the control pulse BVH 5 is carried out with equal voltages on the direct and inverse inputs of the comparator 6.

If, for example, the amplitude of the sensor supply voltage increases, then the comparator will switch earlier, so that the output voltage of the BBX 5 will remain unchanged at a constant pressure force F. Since the formation of a control pulse BWH 5 occurs only when the sensor supply voltage is positive or only at a negative phase (depending on the sign of the reference voltage), the output voltage of the sensor is also detected.

The introduction of a pulse shaper 4 and a BWH 5, which perform the functions of a detector and a compensator, simplifies the circuit of a measuring voltage converter for induction sensors. Thus, the proposed converter (in comparison with the known ones) reduces the conversion error.

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due to the influence of the voltage fluctuations of the power source, at lower hardware costs, which is especially important in multichannel data acquisition and processing systems.

Claims (1)

Invention Formula An inductive sensor voltage transducer containing a power source, a sensor, a pulse shaper and a voltage source, the first output of the power source connected to the sensor power input, characterized in that, in order to simplify the converter while maintaining the accuracy of the conversion, it is entered the sampling-storage unit, and the pulse shaper contains a comparator, three NAND devices, two resistors and a capacitor, the second output of the power supply and the output of the voltage source with are connected respectively through the first and second inputs of the pulse maker with non-inverting and inverting inputs of the comparator, the output of which is connected to the first inputs of the first and second AND-NES elements, to the power bus through the first resistor and to the first output of the second resistor, the second output of which is connected to the second the input of the first NAND element and through the capacitor is connected to the common bus; the output of the first NID element is connected to the second input of the second NAND element, the output of which is connected to both inputs of the third NAND element, the output of which The output of the pulse shaper is connected to the control input of the sampling-storage unit, the second input of which is connected to the output g of the sensor, and the output to the output of the device. 25 thirty shit 40 tf Impilca dyorki . 2