Abstract: In order to increase the resolution and visual quality of the image produced by the transverse magnetic imaging technique, a magnetic printing head has an odd number of stacked elongated comb-type recording head sub-assemblies which are offset relative to each other in the elongated direction. Individual word and bit coincident current-type conductors are wound the gaps between the teeth of each comb such that unidirectional current will generate in the adjacent gaps of each comb magnetic fields in opposite directions along the length of each comb and such that the magnetic fields in like-ordered gaps of adjacent combs are also in opposite directions.

Abstract: Apparatus for controlling the cycles of AC power supplied to a variable thermal load in response to analog signals representing the temperature of the load comprising means for quantizing the analog signals into digital signals and controlling the proportion of integral cycles of AC current blocked to those supplied to said load, while providing a uniform spacing in time of the integral cycles supplied, in accordance with said digital signals. Also means are provided for modifying said digital signals in response to a predetermined average current overload.

Abstract: Coincident current windings on a magnetic print head are driven in a special sequence to minimize undesired spurious printing effects otherwise caused by undesirable concentrations of magnetic flux. Rather than energizing all digit windings (in accordance with supplied data values) for each successive energization of a word winding, the digit windings are driven in multiple sub-sets or groups. Only one such sub-set is energized at any given time and the members of each sub-set are chosen to minimize undesired spurious magnetic flux distributions for any given magnetic printing head configuration.