METHOD FOR DEMAGNETIZING LARGE-SIZED ARTICLES Russian patent published in 2000 - IPC

FIELD: electrical engineering; quality control. SUBSTANCE: method involves exposing a ferromagnetic article to alternating magnetic field which amplitude drops from some maximum value to zero. Its frequency depends on magnetic permeability and thickness of the article. An alternating magnetic field is superimposed over a basic low frequency magnetic field, its frequency being equal to mechanical resonance natural frequency of the article. Magnetic field action under mechanical resonance frequency is achieved by increasing rate of pulse front rise and decay. The action is created by connecting the treating winding to accumulator unit. EFFECT: increased contribution of higher harmonics field; lower current in windings fields. 2 dwg