MAGNETIC TAPE ERASER

摘要

PURPOSE:To obtain an AC eraser of a low power consumption type by using an AC erasing head having an azimuth and then using a coil wound round the core of said erasing head as an oscillating coil of an oscillating circuit which supplies an erasing current. CONSTITUTION:The oscillation frequency of an oscillating circuit 36 is decided by a capacitor 45 and a coil 35 wound round a core 31 of a magnetic material having high permeability of an AC erasing head 46. The coil 35 functions as an oscillating coil and at the same time produces AC magnetic fields at gaps 33 and 34. Then the coil 35 impresses the AC magnetic fields leaked out of the gaps 33 and 34 to a magnetic tape and erases them. In this case, a remaining magnetization pattern obtained after erasion is reproduced by a reproducing head with an azimuth loss since the gaps 33 and 34 have azimuths. Thus the erasion frequency can be set within an audio band, and the impedance of the head 46 is lowered. Therefore the erasion power is also reduced. Furthermore the voltage impressed to the circuit 36 can be reduced less than the conventional level.