| 摘要 |
PURPOSE:To detect the write characteristic of a magnetic head to produce the magnetic head with a high precision by applying a DC bias current to the thin film magnetic head to be examined to measure the reduction of impedance due to saturation of the magnetic core of the magnetic head. CONSTITUTION:The high frequency signal due to an AC oscillator 8 is inputted to a bridge circuit 7, and the output is taken out through a capacitor 13. This output has the amplitude detected by an AC-DC converter 11 after amplified by a differential amplifier 10. This amplitude is proportional to the unbalance of impedance of the bridge circuit 7 which is caused by the impedance of a magnetic head 5, and it is detected as a signal corresponding to the impedance of the magnetic head 5. The current generated from a pulse oscillator 9 is allowed to flow to a conductor winding 4 of the magnetic head 5 as a bias current to magnetically saturate the magnetic head 5 periodically. Magnetic saturation increases the magnetic resistance of the whole of the magnetic core and is detected as the reduction of inductance of the magnetic head 5. |
