SU995037A1 - Device for rejecting cores by pulse magnetic permeability - Google Patents

Description

(5) DEVICE FOR CORRECTING CORE ACCORDING TO PULSE MAGNETIC PERMITTIVITY

one

The invention relates to a magnetic measuring technique and can be used to measure and screen out magnetic cores of a ring shape according to the magnitude of the pulsed magnetic permeability.

A device for measuring pulse magnetic permeability is known, comprising a magnetising pulse generator, the output of which is connected to the Q input sample terminal, an integrator whose input is connected to the output clip sample and measuring device

The disadvantage of this device lies in the fact that when determining the pulse pulse magnetic permeability 6, the value of the latter is judged by the amplitude of the signal at the integrator output. And since an oscilloscope or a volt meter is used as a measuring instrument, the error of the device has an unacceptably large amount (

Closest to the invention is a device for deflecting cores by pulsed magnetic permeability, which contains a generator of magnetizing pulses, the output of which is connected to the input clamp of the sample, the integrator, the input of which is connected to the output as sample of the sample, an electronic switch, two amplitude selectors and a control unit. The device is based on a comparison of the amplitude of the signal at the integrator output with a given level corresponding to the lower boundary of the Fit group. If the read signal exceeds this pre-set level, the controlled core is recognized as suitable and vice versa, if it does not exceed, then it is recognized as defective. 21 The disadvantages of the known device are as follows:

- the boundaries of the group (threshold voltage levels) are set in analog form, changing the boundaries require careful metrological testing by measuring equipment; - in time, the threshold levels under the action of temperature change their values, which necessitates their frequent checks, and this reduces the accuracy and performance of the equipment; - insufficient number of sorting groups (two groups - Fit and Defective), because of which cores with a pulsed magnetic permeability fall into the Defective group, the value of which is both lower and higher than the norm. The purpose of the invention is to improve accuracy. The goal is achieved by the fact that the device containing a magnetizing pulse generator associated with the magnetizing winding, and measuring winding, integrator and electronic key, has a drive divider, mode trigger, counting trigger, two elements AND, element OR, reversible counter, digital-to-analog converter, high-frequency control oscillator, amplitude-time converter, calibration source of signal j, upper and lower limit encoder, upper and lower limit triggers, and desh a flag criterion, wherein the first output of the accumulator is connected to the input of the counting trigger, in series with which the reversing counter, digital-analog converter, controlled high-frequency generator, electronic key, and the second and third outputs of the accumulator are connected to the first through the encoder the input of the lower limit trigger and the second inputs of the lower and upper limit triggers, the outputs of which are connected to the attribute decoder; the output of the magnetizing pulse generator is connected to the first input of the first element I and the input of the divider, the output of the last is connected to the first inputs of the mode trigger, accumulator, upper limit trigger and the second input of the reversible counter, the first output of the mode trigger I connected to the second input of the first I element I, the second output is connected to the third input of the reversible counter, and through the second input of the second element AND with a series-connected element OR, an integrator of an amplitude-time converter and an electronic with a central key, it is connected to the second input of the accumulator, and the source of the calibration signal is connected via the third input of the first element AND to the second input of the OR element, and the measuring winding is connected to the second input of the second element I. In FIG. 1 shows a block diagram of the device; in fig. 2 - time diagram of his work. The device (Fig. 1) contains accumulator 1, counting trigger 2, mode trigger 3, reversible counter 4, digital (; (alog converter 5 (DAC), controlled high frequency generator 6, electronic key 7, encoders upper 8 and lower 9 boundaries, lower bound trigger 10, upper bound trigger 11, 12 signs decoder, magnetizing pulse generator 13, first 14 and second 15 elements AND, divider 16, OR 17 element, integrator 18, amplitude-time converter 19, calibration signal source 20 , input 21 and output 22 clamps clamps sample 23. The first output of the accumulator 1 is connected to the input of the trigger 2 of the counting direction, in series with which the reversing counter 4, DAC 5. controllable high frequency generator 6 and the electronic key 7- the second and third outputs of the accumulator 1 are connected through encoders 8 and 9 boundaries are connected respectively with the first and second inputs of the lower limit trigger 10 and the second input of the upper boundary trigger 11. The outputs of the trigger 10 and 11 are connected to the inputs of the decoder 12 features. . The second output of the magnetizing pulse generator 13 is connected to the inputs of the first element I 14 and the divider 16, the output of the latter is connected to the first inputs of the trigger 3 mode, drive 1, the upper limit trigger 11 and the second input of the reversible counter 4. The first output of the trigger 3 mode is connected to the second the input of the first element And 14, the second output to the third input of the reversible counter 4, and through the second element AND 15 the element OR 17, the integrator. 18, the amplitude-time converter 19 and the electronic key 7 are connected to the second input of accumulator 1. The source 20 of the calibration signal is connected through the first element AND 14 to the second input of the element OR 17. The input 21 and output 22 terminals of the sample 23 are connected correspondingly with the first output to the generator 13 magnetizing pulses and the second input of the second element And 15. The device works as follows .. The generator 13 of magnetizing pulses produces a sequence of pulses shifted relative to each other (Fig. 2) E: The pulses from the second The second output of the generator 13 goes to divider 16, which reduces their frequency, for example, 10 n times, where n is any integer. The trigger 3 of the mode, changing the state with the overflow frequency of the divider 16, alternately forms calibration and measurement intervals (Fig. -2.0). At the beginning of each interval, the divider 16 performs the resetting of the accumulator 1 and the trigger 11 of the upper boundary of the Fit group (Fig. 2i). The calibration interval at the input of the amplitude-time converter 19 through the first element 14 and the element 17 and integrator 18 receives calibration pulses, the amplitude of which is given by the source 20 of the calibration signal (Fig. 2 (), and the follow frequency is equal to the frequency of the generator 13. Amplitude -time transducer 19 generates pulses (Fig. 26), the duration of which is proportional to the amplitude of the calibration signals. The pulses of the controlled high-frequency generator 6 when the signals from the amplitudes appear at the input of the electronic key 7 bottom-time converter 19 is passed to accumulator 1 (Fig. 2y. If the number of pulses in the calibration interval on accumulator 1 does not overflow it. T | eigger 2 of the counting direction retains its original state and At the end of the interval, the reversible counter k increases its state by one (Fig. 245). This increases the potential at the output of the DAC 5 and, therefore, the frequency of the controlled oscillator 6. Therefore, at the next calibration interval at the same value, the calibration signal to the input of the accumulator 1 will pass more pulses. The described process repeats until the trigger 2 of the counting direction detects an overflow of accumulator 1. The state of the reversible counter A decreases by one, causing a decrease in the potential at the output of the DAC 5 and, consequently, the frequency of the controlled oscillator 6. Small frequency resolution, necessary to achieve high measurement accuracy, is provided by the appropriate choice of the number of bits of the reversible counter and. DAC 5. Thus, in the calibration interval, instead of the read signal, the gauge is fed into the measuring circuit. A stable signal of a stable size provides automatic adjustment of the parameters of the measuring circuit to such values at which the calibration signal causes a complete filling of the signal 1. In the measurement interval, the pulses read from the output terminal 22 of the test sample 23 through the second element AND 15 are the OR element 17 and the integrator 18 are fed to the amplitude-time converter 19. In the same way as described, filling in accumulator 1 occurs. If the code in accumulator 1 does not reach the value specified by the encoder 9, the lower limit trigger 10 maintains the initial state, and the decoder of 12 signs at the end of the interval generates a Marriage signal below the norm. If the code in drive 1 exceeds the specified value, the lower limit trigger 10 goes into one state. If the code in the accumulator 1 also exceeds the value specified by the encryption, the upper boundary rator 8, the lower limit trigger 10 (Fig. 2i, k) returns to the initial state, and the upper limit trigger 11 goes to the single state. The decoder 12 signs, respectively, produces signals Fit or Marriage above the norm {Fig. 2). For on-line analysis, the current value of the monitored parameter can be displayed on a digital indicator that fixes the code in drive 1 after passing the last parcel on the measurement interval. Introduction to the splitter device 16 of the flip-flops 2 and 3, the reversible counter 4, the DAC 5 of the controlled high-frequency generator 6 and the calibration signal source 20 improves the accuracy of determining the informative parameter, since these elements provide automatic

calibration of the measuring circuit of the device.

Introduction of the accumulator 1, the encoder bottom 9 and top 8 boundaries to the device, and the decoder 12 features simplifies the maintenance of the device. In this case, the boundaries of groups are set in digital form, which is simpler, more detailed, and it is also possible to change the boundaries of the group, if necessary, without having to use special monitoring and measuring equipment. In addition, operational control of the current value of the measured parameter becomes possible. An increase of 15 the number of sorting groups is provided, which improves the performance of the equipment.

The technical and economic effect from the use of the proposed device consists in increasing the accuracy of determining the monitored parameter, increasing the productivity of the control by increasing the number of groups and reducing maintenance costs.

Claims (1)

1. Seleznev Yu.V. and others. Automatic control of magnetic parameters. M. Higher School, 19712. Author's certificate of the USSR No. 552579, cl. G 01 R 33/12, 12.01.76. f gz ff  DW) i / MjttiMf,