| 摘要 |
PURPOSE:To simplify circuit constitution by supplying a common bias winding with an AC bias current which has a superposed direct current, and then supplying a unidirectional signal current to each magnetic head. CONSTITUTION:Waveforms of recording currents supplied from amplifiers A1- Ak are supplied as unidirectional pulse currents to signal windings n1-Nk of respective magnetic heads M1-Mk. As an AC bias, the current consisting of the current of a high-frequency bias power source B and a DC current from a DC voltage source E is supplied to a bias winding nb. In this case, the DC current is set to cancel a residual magnetism component, so no residual magnetism component in a polarized state remains on a magnetic tape Ta. |
