SHORT-TIME TEST DEVICE FOR ITEMS FROM ELECTROTECHNICAL STEEL PLATES Russian patent published in 2011 - IPC G01R33/00 G01R33/12 

FIELD: electricity.

SUBSTANCE: invention is designed for measurement of dynamic hysteresis loop and the main magnetisation curve of items from electrotechnical steel plates at frequencies of 1 to 10000 Hz. Short-time test device for items from electrotechnical steel plates includes AC source, differential magnetic bridge applied to the tested specimen and representing H-shaped core from permalloy, to neutral section of which there applied is measuring coil, and to four poles - similar magnetising coils, which are connected in series so that lower and upper coils are connected to each other in alignment, and pair of upper and pair of lower ones are connected in opposite manner, and connected to AC source output. AC source consists of sine voltage generator and AC amplifier the first input of which is connected to output of sine voltage generator and the second one is connected to measuring coil output. Current sensor is connected in series to magnetising coils. Device also includes memory unit with delay of output signal relative to input signal for one fourth of period of output voltage of generator; the first input of memory unit is connected to output of measuring coil, and the second one is connected to the second output of sine voltage generator, recording unit having two inputs; the first one is connected to output of memory unit and the second one is connected to current sensor output.

EFFECT: possibility of measuring magnetic induction and intensity of magnetic field in the tested specimen; increasing test speed and improving measurement accuracy.

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