| 摘要 |
A series resonant AC erase head drive circuit apparatus for use with a miniaturized cartridge-type tape drive includes apparatus for generating a non-overlapping pulse wave forms and for driving switches, power switches and a voltage controlled DC current source. The pulse form generating and power switch driving apparatus includes a clock frequency input coupled to an externally supplied clock frequency signal and an enable input coupled to an externally supplied enable signal, and includes a plurality of power switch driving outputs. The power switch driving outputs provide a plurality of power switch control signals which include a non-overlapping interval. Power switches are coupled to the pulse form generating and power switch driving apparatus for switching power to the erase head in an AC fashion in response to the plurality of power switch control signals so as to allow current to flow through the erase head in a first direction for a first time interval, in a second, opposite direction for a second time interval and so as to prevent current from flowing through the erase head during the non-overlapping interval. The power switching apparatus comprises a series resonant H bridge circuit. Apparatus for providing a voltage controlled DC current source is coupled to the power switching apparatus. The erase head drive circuit is capable of operating at clock frequencies greater than 3.6 MHz.
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