SU1033947A1 - Eddy-current checking device - Google Patents

Description

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CO 4 The invention relates to non-destructive testing and can be used to measure electrical conductivity, electroplating thickness and defectoscopy. A phase flaw detector is known, comprising a generator, a sensor, a reference and measuring channels consisting of amplifiers according to a common emitter with two-diode limiters, transformers, phase detector on triggers, indicator With the disadvantage of the device is low temperature stability, due to the significant phase error in the circuit blocks, More closely to the invention, the technical entity is a device for an eddy current controller, comprising a generator, a three-coil eddy current converter (EPR) connected to it, and a phaser and indicator 2. This device measures the phase difference between the signals of the reference and measuring channels, which is a function of the monitored physical quantity. Selective amplifiers serve to isolate the first harmonic from square-wave signals formed by limiters. The amplitude constant sinusoidal signals from the outputs of the selective amplifiers are fed to the inputs of a balanced diode phase-sensitive detector, the output constant voltage of which is proportional to the phase difference of the input voltages. The disadvantage of the device is low control accuracy, due to the low temperature stability of the blocks. The purpose of the invention is to show the accuracy of the control. The goal is achieved by the fact that a device for eddy current testing, containing a generator connected to it / sin-winding vikh retokovy converter (VTP) and the phase shifter and indicator, is equipped with a consistently connected first second and third differential amplifiers limiting, circuit 2 OR, pulse shaper stable amplitudes and an RC circuit, included between the ETP output and the indicator input, and the fourth differential limiting amplifier, connected between the output of the phase shifter and the second input house of the circuit 2 OR, the drawing shows a block diagram of a device for eddy current testing. The device for eddy current testing contains a series-connected, one-generator 1, VTP 2, first, second and third limiter amplifiers 3 i and 5. logical element OR, driver 7 stable amplitude pulses, RC-circuit 8 and indicator 9, and connected in series the phase shifter 10 and the fourth amplifier-limiter 11 connected between the output of the generator and the second input of the logic element 2 OR. The device works as follows. The generator 1 of sinusoidal oscillations feeds the exciting winding of the ECP sensor (not shown). The voltage from the generator is also fed to the input of the phase shifter 10. Signals taken from the phase shifter 10 and the VTP test and compensation windings connected in series (not shown) are fed, respectively, to the inputs of the reference and measurement channels, which include differential amplifiers-limiters 3-5 and 11, made under the scheme GENERAL MANIFOLDER GENERAL BASE. The number of series-connected limiting amplifiers in the channels is chosen sufficient to provide the necessary steepness of the square fronts at the outputs of the channels. The logic element 6 on the current switches performs the logical addition of rectangular pulses from the outputs of the reference and measurement channels. The output voltage of the logic element, which is a pulse with a lithium proportional to the measured phase difference, and with an amplitude limited by the mode of its operation, is fed to the driver 7 of stable amplitude pulses. Volt-second area of the output voltage of the shaper of 7 pulses of a stable mplitud is proportional to the measured phase difference. To the output of the form .3 yuzze 4

The inverter 7 pulses of a stable ampere in phase shift, which the RC circuit 8 is connected to at the onset, highlights the increase in the temperature steel constant component of the device, as well as pulsed voltage. The result is to reduce the working currents of the elements.

The measurement is fixed by the indicator 9 5 to reduce power consumption.

Due to the introduction of differential inherent differential amplifiers-limiters according to the schetelit m-limitite m according to the scheme GENERAL

GENERAL COLLECTOR - OBU | AH BASE logical-COLLECTOR - OBVA | AYA BASE and logical

Element 2 OR on the switch element 2 OR on the switches “1”, pulse stabilizer-1bka high input and low output

Noise amplitude and RC circuits improve di-impedances allow for

characteristics are reduced, the connection of these elements with each other with

the phase error of the device and the breeder using simple means that leads

The effect of temperature variation is simplified to simplify the design of the device.

Claims (1)

DEVICE FOR Eddy current monitoring, containing a generator, a three-winding eddy current converter (ETC) connected to it and a phase shifter and an indicator, characterized in that, in order to increase the accuracy of control, it is equipped with first, second and third differential amplifiers-limiters connected in series, circuit 2 OR , a stable-amplitude pulse shaper and an RC circuit connected between [the ECP output and the indicator input, and • the fourth differential limiter amplifier connected between the ph ovraschatelya and a second input of the circuit OR 2. I „„ 1033947 1 1033947 2