DISC TORQUIKING APPARATUS

摘要

The file includes a disc rotary drive mechanism, a transducer head for data transfer with the disc and a radial drive mechanism comprising a four-phase stepping motor for radially moving the head of the disc. The motor has a rotor and sets in four phases windings arranged sequentially. A control circuit normally energises the windings in a single phase drive mode to cause rotation of the rotor in discrete increments. The circuit energises at least one of the windings on each set for the preassigned length of time when the file is electrically tuned on and to start energising the first phase windings upon lapse of the preassigned length of time.