MAGNETIC TAPE RECORDER FOR DIGITAL SIGNALS

To permit recording of digital data in a digital code using d-c level, particularly for recording of digital video data by a rotating video transducer (4, 5, 29) on a rotating head wheel (6) of a scanner, without degradation of recorded signals due to d-c shift upon an extended sequence of bits of the same polarity, two current generators (30, 31) are provided, each supplying a current of opposite polarity, connected to a logic circuit which connects, selectively, current of the respective polarity in accordance with the respective bit to the transducer, so that, at each time, and corresponding to the respective bit, the current through the transducer will be of sufficient magnitude to change the magnetic properties of the magnetic tape (T), then in contact with the transducer, to saturation in the direction controlled by the direction of current flow through the transducer head. A d-c restoring clamping circuit (27) and logic control circuit (34, 35) to control the current switches (32, 33) is located as a unit (12) on the head wheel (6) itself, which receives the signals via non-contacting transducers (9, 23, 24). A non-contacting power supply (26, 40) transfers power from the stator (20) to the rotor (21) of the scanner (1, 2).