| 摘要 |
PURPOSE:To make the residual magnetic flux to almost zero, by zeroing the magnetic field, after the application of magnetic field less than coercive force of opposite polarity, after the magnetization in saturation, in DC demagnetization of magnetized magnetic material. CONSTITUTION:The magnetic substance 5 has the saturated magnetic flux with the magnetizing signal. When the demagnetizing signal is applied. The voltage difference between the dividing voltage and the reference voltage by the thermister 9 and the magnetic resistive element 8 for monitor is produced at the voltage comparator 20, the flip-flop 26 is set at the trailing of demagnetizing signal, and it is fed to the relay driving circuit 27. On the other hand, the output of the flip-flop 26 operates the resistance control circuit 31, the resistance value of the variable resistor element 24 is decreased, and a reverse current flows to the electromagnetic coil 10. Thus, the magnetic flux density of magnetic substance reduces on the hysteresis curve, and the supply of demagnetizing current is stopped when the output of the voltage converter due to the change in the resistance value of the magnetic resistive element is inverted, and complete demagnetization is made by removing the magnetic field. |
