SU1450114A1 - Arrangement for calibrating the electric part of remote measurement system - Google Patents

Abstract

The invention relates to the field of telecommunications, m. used in telemetry systems, automatic control systems and data transmission systems. The purpose of the invention is to increase the calibration accuracy. The device contains a block 1 of strain gages, a converter of 2 information signals, a source of 3 sync pulses, rc 4 of a calibration signal, a block of 5 calibration consisting of a regulating block 6 and a resistor 7. 1.1 differential amplifiers 9, an operational amplifier (op-amp) 10, a rectifier 11, and a multiplier 12, consisting of a PA and a low-pass filter. Calibration of the measuring channel occurs by changing the total resistance of unit 5, and this value is maintained by the input of remote control 8, 9, multiplier 12, op-amp 10 and top 11, which is independent of the current and voltage in the unit of 1 ton. was proportional to the calibrating voltage at the output of Mr. 4. Mr. 4, synchronized from source 3, generates a control signal that determines the necessary law of change in the magnitude of the unbalance. The magnitude of the imbalance is determined by the control voltage on block 6 and is independent of the voltage on the strain gages of block 1 and the current through them. 1 hp ff, 2 ill. and S (L f.f

Description

The invention relates to telecommunications, can be used in telemetric systems, systems

automatic control and data transmission systems, the signal sources of which are strain sensor sensors.

The aim of the invention is to improve the accuracy of the calibration.

Fig. 1 shows the structural electrical circuit of the device for calibrating the electrical part of the telemetry system; 2 is a structural electrical circuit of a resident 15 resident.

The device contains a block 1 strain-resistance resistors, a converter of 2 information signals, a source of 3 sync pulses, a generator 4 of a calibration-20 signal, a calibration block 5 consisting of a regulating block b and a resistor 7, the first 8 and second 9 differential amplifiers, an operational amplifier 10, a rectifier 11 and 25 multiplier 12 consisting of a digital-to-analog converter .13 and a low-pass filter 14.

The device works as follows

at once.

Block 1 is affected by a measured physical quantity. In this case, the strain gage bridge (half bridge) of unit 1 is unbalanced. The midpoint potential of the bridge circuit, proportional to the magnitude of the imbalance and the supply voltage of the bridge (half bridge) of unit 1, is fed to the converter 2, where the component depending on the magnitude of the imbalance occurs and transmitted to the communication channel. Source 3 provides synchronous operation of converter 2 and generator 4, and the presence in the transmitted signal of the calibration signal is indicated in the communication channel by special service feeds. Calibration of the measuring channel occurs by changing the total resistance of block 5, and this value is maintained by the first 8 and second 9 differential amplifiers, multiplier 12, operational amplifier 10 and rectifier 11 independent of current and voltage in block 1 so that that the imbalance is proportional to the calibrating voltage at the output of the generator 4. The generator 4, synchronized from source 3, generates

five

0

5 0 j

The control signal determines the necessary law for changing the magnitude of the unbalance. This signal is fed to the first input of the multiplier 12, to another input from the output of the second differential amplifier 9, a signal proportional to the voltage drop at block 5. Then the inverting input of the operational amplifier 10 receives a signal proportional to the voltage drop, at block 5 and calibration voltage. The other non-inverting-1 input of the operational amplifier 10 from the output of the first differential amplifier 8 receives a signal proportional to the current flowing through the resistor 7. Operational amplifier 10 amplifies the difference of these sigg :. It also transfers the control unit to the control unit through the rectifier 11. 6

Thus, the amount of imbalance is determined by the control voltage on the regulating unit 6 and does not depend on the voltage on the strain gauges of the bridge (half-bridge) circuit of unit 1 and the current through them.

Claims (2)

1. A device for calibrating the electrical part of a telemetry system, comprising parallel-connected .. resistance strain gauge blocks, a calibration block consisting of a series-connected regulating unit and a resistor, as well as an information signal converter, a calibration signal generator and a clock source, the outputs of which are connected to clock inputs calibration signal generator and information signal converter, the input of which is connected to the output of the resistance strain gauge unit, is This is due to the fact that, in order to improve the calibration accuracy, first and second differential amplifiers and serially connected permocables, an operational amplifier and a rectifier, the output of which is connected to the control input of the regulating calibration unit, the first differential amplifier are connected, whose subtracting input is combined with the subtracting code of the second 14501 a differential amplifier whose summation is combined with the output of a strain gauge block, the output of the calibration signal generator is connected to the first input of the multiplier, to the second input of which the output of the second differential amplifier is connected, and the output of the first differential amplifier is connected to the second input of the operational amplifier. .. 14 2. A POP.1 device, characterized in that the multiplier comprises a serially connected digital-analog converter and a low-pass filter whose output is the output of a multiplier whose first inputs are an information input of the digital-analog converter whose reference voltage input is the second input multiplier / J / f 1st year