Abstract: In a video tape recorder of the helical scan type, a pair of rotary magnetic heads for the audio signal are provided in addition to the rotary video heads so that the audio signal is recorded on the same slant track as of the video signal on a multiplex basis. The audio head pair is provided with an azimuth angle with opposite polarities from each other and different in value from that of the video head pair. The system has a first operation mode of the standard tape speed and a second operation mode in which the tape is fed at a speed, for example, 1/3 the standard tape speed. The audio and video head pairs are disposed on lines intersecting at right angles with an offset of T.sub.1 /2+T.sub.1 provided in the axial direction of rotation between the two magnetic head pairs, where T.sub.1 is the track pitch of the recording track formed on the tape in the second operation mode. The system produces overlapping tracks for the audio and video signals on the magnetic tape.

Abstract: In a video tape recorder or audio tape recorder, the remaining tape length indicated as time or taken-up tape length indicated as time is calculated by use of microcomputer and then accurately indicated as a time length by detecting the angular velocities of a supply reel and a take-up reel. A rotational period of time of each reel is detected twice, so that the tape running speed is calculated from the two detected values and the known tape caliper thickness, thus calculating and indicating the remaining tape length indicated as time and the taken-up tape length indicated as time. The remaining tape length and taken-up tape length indicated as time in such operation modes of a tape recorder as fast forward, and rewind, as well as recording and reproduction are accurately indicated.

Abstract: Disclosed is a drive system for a motor, wherein a current proportional to a change of a load of a motor is sensed by a sensing resistor. A voltage produced across the sensing resistor controls an electronic switch in a manner that the output DC voltage of a DC - DC converter is used for a motor drive power source at a normal load and yet a DC power source with a higher voltage than the output DC voltage of the DC - DC converter is used therefor at an increased load.

Abstract: A tuner comprising a plurality of cylindrically assembled bases supported between a pair of support plates secured to a rotatable shaft, receiving circuit blocks for receiving waves in different frequency bands being provided in groups on the inner side of said bases, whereby it is possible to reduce the space requirement for the whole tuner construction and make ready adjustment of the individual receiving circuit blocks.