Abstract: An oscillating erase current circuit for erasing information recorded on magnetic media. The inductance of an erase head is coupled with capacitors to form a tank circuit having a natural resonant frequency. The self-oscillating erase current circuit generates an oscillating signal having a frequency of oscillation determined by and therefore equal to the natural resonant frequency of the tank circuit. Once enabled, the self-oscillating erase current circuit continuously oscillates without any external drive circuit.

Abstract: A circuit apparatus for driving a magnetic head to generate a magnetic field wherein a driving frequency of the magnetic head is increased and a recording density of an information recording medium is raised. In this circuit apparatus, a bridge circuit is constructed in which a chief coil for generating a magnetic field is arranged between a first connection node disposed between a serially connected first auxiliary coil and first switch element and a second connection node disposed between a serially connected second auxiliary coil and second switch element, and the magnetic field is modulated in accordance with an information signal by on-off control of the first and second switch elements to change the direction of current flowing in the chief coil. Further, third and fourth switch elements are respectively connected in parallel with the first and second switch elements so that a current path of the chief coil is separated from respective current paths of the auxiliary coils.