Abstract: A bistable hysteretic integrated circuit is designed such that the hysteretic characteristic is determined by the ratio of the resistances of two resistors.

Abstract: The uniformity of density of characters printed by thermal printers upon thermally sensitive paper is enhanced by controlling the amount of energy supplied to the print head during subsequent printings before the print head has completely cooled to ambient temperature. To obtain the desired uniformity the energy supplied to the print head for subsequent printings is made proportional to the energy lost by cooling of the print head between printings. This results in the print head being reheated to substantially the same printing temperature for each printing of a character or character segment.By using a dot driver having an R-C circuit that recharges the capacitor between print pulses at a rate that is proportional to the thermal time constant of the print head, the energy stored by the capacitor can then be used to re-heat, or control the re-heating, of the print head to substantially the same selected print temperature. By maintaining the R-C charging time constant substantially between 0.1.tau. and .tau.

Abstract: A method and apparatus for rotating through a selected angle the polarization vector of a substantially linearly polarized electromagnetic beam by using three or four reflections with the output electromagnetic beam being substantially free of ellipticity. By selecting the second and third angles of incidence such that the ellipticity introduced by the second reflection is cancelled by the third reflection and the first and fourth angles of incidence which introduce substantially no ellipticity, the polarization vector of the incident electromagnetic beam need not be restricted to being parallel or perpendicular to the incident plane.

Abstract: A transformer bobbin assembly having a first bobbin piece dimensioned to accommodate at least one additional bobbin piece within its central cavity. Each bobbin piece having a pair of flanges, one at each end and perpendicular to its central cavity, defining a channel around the outer surface of the bobbin piece to accommodate a single coil winding. The surface distance over the flange of the larger bobbin piece from the end of its cavity to the top of the flange plus the thickness of this flange is selected to provide at least the minimum creepage and clearance distances required by a selected industrial safety standard.If two bobbin pieces, each being fully insertable within the interior cavity of the larger bobbin piece, are utilized, the necessary creepage and clearance distances between the coil wound on each of these nesting bobbin pieces is provided by a web within the cavity of the larger bobbin piece. This web is centrally located within and parallel to the flanges of the larger bobbin piece.

Abstract: Spurious emissions caused by a newly-described vibration mode in an acosutic imaging transducer are suppressed by cancelling the net displacement of the center of mass of each piezoelectric element in the transducer array.