SU385320A1 - DEVICE FOR THE CONTROL OF RODS COVERED BY A FERROMAGNETIC FILM - Google Patents

Description

one

This invention relates to memory devices.

A device for testing rods coated with a ferromagnetic film is known, which contains a measuring module connected to an electromechanical drive, a block of numerical current formers, the outputs of which are connected to the numerical windings of the measuring module, a calibrating current driver, a bridge circuit, one arm of which includes a test rod and a compensating a wire, in a diagonal - a block of shapers of discharge current, on the other shoulders - the primary windings of a transformer. The secondary winding of the transformer through the switch and the relay contacts is connected to one inputs of amplifiers-discriminators, the other inputs of which are connected to the control unit, and the outputs to the inputs of the drive control unit.

The disadvantages of the known device are low speed and low reliability of the control.

The proposed device differs from the known one in that it contains a calibration roller, strung on a compensation wire and connected via a variable resistor to a calibration current driver. This makes it possible to increase the accuracy and fast operation of the device.

2

Pa figs. 1 shows a block diagram of an apparatus for monitoring rods coated with a ferromagnetic film; in fig. 2 - drive control unit, one of the options. The device contains a bridge readout circuit /, in one arm of which the checked rod 2 and compensation wire 3 are included, in the diagonal-shaper of discharge current 4, in the other shoulders - primary windings 5 and 6 of the transformer 7. Secondary winding 8 of the transformer through the switch 9 and the PI relay contacts are connected to the same inputs of the discriminator amplifiers 10 and 11, the other inputs of which are connected to the unit

control 12, and the outputs - to the inputs of the control unit of the drive 13. To the inputs of the amplifiers-discriminators 10 and // also connected to the divider of resistors 14 and 15.

The device also contains a measuring module 16 connected to an electromechanical drive 17, consisting of an engine 18. two pulleys 19 and 20 with a cable 21 draped over them. A measuring module 16

there are numerical windings 22 connected to a block of drivers of numeric currents 23, a calibration coil 24 strung on a compensation wire 3 and connected via a variable resistor 25 to the driver of a calibration current 26.

The bridge circuit 1 also includes balancing resistors 27 and 28, clamping contacts 29-32.

The device contains limit switches KBi and KBG, with which the measuring module interacts.

The drive control unit 13 (see Fig. 2) contains a transistor switch 33 with a PZ relay connected to the collector circuit and a control button 34, one-shot 35, pulse driver 36, OR 37 circuit, AND 38 circuit, 59 trigger, two delay circuits 40 and 41. At the same time, the outputs 42 and 43 of the amplifiers-discriminators W and 11 are connected to one of the inputs of the OR 37 circuit and the input of the delay circuit 40, respectively, and the output 44 of the one-oscillator 35 is connected to the transistor 33.

The device operates as follows.

The test rod 2 is passed through the system of numerical windings 22 and is fixed by contacts 30 and 32. The discharge current is fed to the diagonal of bridge circuit 1. When reading, the signal from the secondary winding 8 of the transformer 7 through the contacts of the relay PI goes either to the inputs of the amplifiers-discriminators 10 and 11, or to the input of a divider consisting of precision resistors 14 and 15. The divider resistance is chosen equal to the input resistance of the amplifiers.

Before testing, the measuring module 16 is in the leftmost position (see Fig. 1), which is the initial one. In this position, the limit switch contact K.Bi closes the relay circuit Pj. When triggered, the PI relay disconnects the numerical current generator 23 and turns on the calibration current driver 26 supplying the calibration coil 24. At the same time, the PI relay switches the inputs of discriminators 10 and 11 from the output of the transformer 7 to the output of the divider consisting of resistors 14 and 15. V In this state of the measuring module 16, a large portion of the film is switched on the compensation wire 3 (the number of turns of the calibration coil 24 is large enough). A large amplitude switching signal, the magnitude of which can be measured on an oscilloscope screen and set within the desired limits by a variable resistor 25, is fed to the input divides-el. The division ratio of the divider is known in advance. The signal from the output of the divider is fed to the inputs of amplifiers-discriminators 10 and 11.

The trigger threshold of the amplifier-discriminator 10 is set by the lower level of discrimination of the read signals, and the threshold of the amplifier-discriminator 11 is set by the upper level of discrimination. In the neutral position of the toggle switch 45, the button 34 is pressed. The lamp 46 goes out and the device is ready to check the rod. The described method of obtaining calibrated signals has several advantages, the main ones of which are:

1. For calibration, a film switch signal having the same frequency spectrum as the read signals from the test rod is used.

2. A calibration signal is generated in the readout circuit itself, and therefore, interference and attenuation introduced by the circuit are taken into account. After setting the trigger thresholds of the discriminating amplifiers 10 and 11, the toggle switch 45 is moved to the right position and the testing of the rods begins.

Each reading cycle from the control unit 13 to the input 47 of the trigger 39 receives a pulse. If the amplitude of the read signal is greater than the trigger threshold of the amplifier of the discriminator 10, then a standard amplitude pulse is generated and is fed to the input 48 of the trigger 39. A low potential from the output

trigger 39 is fed to the input of the circuit “And 38 and, delayed by the delay circuit 41, the signal through the circuit“ And 38 does not pass. Under these conditions, the potential at the output 44 of the one-shot 35 is high, the transistor switch 33 is closed and

verification continues. In the case of a defective point on the lower level of discrimination (or a calibration at the beginning of the test cycle), the pulse at the output of the amplifier-discriminator 10 is absent and the potential at the output of the trigger 39 is high. The pulse delayed by the delay circuit 41 passes through the circuit "AND 38, the one-shot 35 is generated and starts. The pulse width of the one-shot 35 is chosen by a little

longer PZ relay response time.

When triggered, the Pz relay self-locks, stops the engine 18, and turns on the lamp circuit 46. According to the position of the measuring module 16

and the metric ruler attached to the device manipulator (not shown in Fig. 1) determines the location of the rejected rod point. The drive 17 also stops when there is a pulse at the output 43 of the amplifier-discriminator 11, which means that there is a defective point in the upper level of discrimination.

In the case when checking is not required

the top level of discrimination, the amplifier / discriminator // can be disabled. By pressing the button 34, the measuring module 16 is moved from the rejected point and the engine 18 is restarted.

Note that the output signals of the one-shot 35 can be used to fix the rejected point in another way (for example, using a digitizer without stopping the measurement module 16). When the measuring module reaches the rightmost position, the limit switch HF stops the engine 18. The toggle switch 45 is turned to the left position, the button 34 is pressed and the test cycle continues. The next calibration check and

The control of the new rod begins in the leftmost position of the measuring module 16.

Subject invention

A device for testing rods coated with a ferromagnetic film, containing a measuring module connected to an electromechanical drive, a block of numerical current formers, the outputs of which are connected to the numerical windings of the measuring module, a calibrating current driver, a bridge readout circuit, one arm of which includes a test rod and a compensation bar the wire in the diagonal block of shapers of the discharge current, in the other shoulders, the primary windings of the transformer, the secondary winding of which through the switch and the relay contacts are connected to one inputs of amplifiers-discriminators, the other inputs of which are connected to the control unit, and the outputs to the inputs of the drive control unit, characterized in that, in order to improve the accuracy and speed of the device, it contains a calibration coil strung on a compensation wire and connected via a variable resistor to the calibrator current driver.

u-i ;;;,

Pvi one