SU920589A1 - Device for checking magnetic cores - Google Patents

Description

(54) DEVICE FOR THE CONTROL OF MAGNETIC CORE

one

The invention relates to the measurement of magnetic quantities and is intended to automatically control the magnetic characteristics of the cores used to manufacture the memory elements of switching devices on reed switches.

A device for determining the magnetic properties of samples of magnetic materials is known, which contains a magnetizing device, an alternating magnetic field generator, a ballistic galvanometer, and a low-pass filter. By acting on a test sample at the same time by a constant field, corresponding to the measured induction value, and by a damped field variable field, a hysteresis-free magnetization of the test sample is performed. Then the circuit of the ballistic galvanometer is closed and an alternating magnetic field is switched on, the amplitude of which is sufficient to saturate the sample. The average

the value of induction in the sample varies from the desired to zero and the resulting induction increment is equal to the measured value. This resulting value is determined by the ballistic galvanometer l.

However, this device is characterized by insufficient accuracy and low productivity.

It is also known a device for

10 permanent magnets control and Production control of magnetic properties of magnets for reed relays and ferrite matrices. This device contains a magnetizing current block.

15 demagnetizing current unit, nama | pull-down and measuring windings, flow meter of induction setpoints, comparison units, voltage meter, block of voltage settings.

20, this device measures the parameters of the limiting hysteresis loop of the material from which the cores are made. Using a block of magnetizing current to ensure the saturation of the test sample. In the block of induction settings and in the block of intensity settings, the values of the settings corresponding to the specified values of induction and magnetic field strength are set. Then, using a demagnetizing current unit, the current in the magnetizing winding changes smoothly, while the intensity meter continuously measures the magnitude of the magnetic field at the surface of the core. 3 The moment when the surface tension becomes equal to the value of the setpoint voltage, the demagnetizing current unit turns off and the magnetizing current unit and the flow meter turn on. The sample is again transferred to the saturation state and the flow meter measures the magnitude of the magnetic flux increment in the controlled core 2. The core is considered suitable if each of the parameters of the parameters is within the normal range. The control of cores for each of the parameters makes it impossible to take into account their interconnection. The quality of the core is determined by its geometrical dimensions and magnetic parameters of the material from which it is made, therefore the output. several parameters outside the permissible range could be neutralized by the optimal value of the remaining parameters. Thus, the control of certain parameters does not reflect the real quality of the cores and leads to the rejection of a larger number of practically fit cores. In addition, the use of repeated magnetization reversals and magnetizations leads to a decrease in productivity and complication of equipment. The aim of the invention is to improve the accuracy of the control. This goal is achieved in that a device for controlling magnetic cores containing a synchronizer connected in series, a voltage setting block, a DC block whose output is connected to a magnetizing winding located on a controlled core, and also a magnetomotive unit of comparison. force, the first input of which is connected to a registering device connected to the second output of the synchronizer, a set of magnetomotive force settings, an alternating damping current generator, a magnetomotive force meter and a demagnetize winding located on the controlled core and connected to the output of the alternating damping current generator whose input with the third output of the synchronizer, the fourth output of the synchronizer is connected to the input of the block of settings of the magnetomotive force, the output of which is connected to the second th comparing unit input magnetomotive force and magnetomotive force meter connected to an input of the recording devices. FIG. 1 is a functional diagram of the device; FIG. 2 is a graph explaining the operation of the device. A device for monitoring magnetic cores contains a synchronizer 1 connected in series (Fig. 1), a voltage setting block 2, a DC unit 3, the output of which is connected to a magnetize winding 4 located on a controlled core 5. The second output of the synchronizer 1 is connected with its first the input of the registering device 6, the second input of which is connected to the magnetomotive force meter 7, and the output is connected to the first, the input unit of the magnetomotive force comparison unit 8. The second input of the magnetomotive force comparison unit 8 is connected to the output of the magnetomotive force setting unit 9. On the controlled core 5, there is also a demagnetization winding 10 connected to the output of the alternating damping current generator 11, the input of which is connected to the third output of synchronizer 1, and the fourth output of synchronizer 1 is connected to the input of block 9 of the magnetomotive force settings. The device works as follows. In the controlled core 5, a degrading winding 10 connected to an alternating damping current generator 11 creates a smoothly falling alternating magnetic field. Due to the effect of this field, the core 5 is brought to the initial (demagnetized) state (Fig. 2,

point 0). Thus, the core 5 (Fig. 1) is prepared for measurement.

In block 2 of the settings of the junction, the value of the setpoint is equal to the average value of the coercive force of this group of cores HFD (Fig. 2). Using the DC unit 3, a current corresponding to the HDO is set up in the magnetizing winding unit 6 and a magnetomotive force comparison unit 8. The meter 7 determines the magnitude of the magnetomotive force developed by the core 5 corresponding to the point A (Fig. 2) of the main magnetization curve of about. Next, synchronizer 1 (Fig. 1) turns off the alternating damping current generator 11 and the registering device 6, and in the winding k magnetization c using a DC unit 3, a current is set to ensure the saturation of the monitored core 5. After this, the DC block 3 is turned off and the recording device 6 is turned on, determining the magnitude of the remaining, point of the magnetomotive force , Respectively .stvuyuschey point B (FIG. 2) at the intersection of a hysteresis loop of the demagnetization curve t and the load straight S.,

The measurement result with the aid of block 8 of the comparison of the magnetomotive force {FIG. 1) is compared with the set value of the magnetomotive force, recorded in block 9 of the settings of the magnetomotive force. If the measurement value at the point. A (Fig. 2) does not exceed, and at the point B exceeds the predetermined values for these parameters, the core 5 is suitable for installation in the magnetic system of the switching device.

The proposed device improves the efficiency of control, due to the increased output of cores recognized as suitable, and the efficiency of control.

Claims (2)

1. Authors certificate of the USSR. No. 3852Ai, Cl. G 01 R 33/12, 1971. 2. USSR author's certificate If 55060, cl. G 01 R 33/12, 197.