Abstract: An apparatus amplifies a signal in two different modes. The apparatus amplifies the signal in a linear mode when the voltage of the signal is much less than the voltage of the power source, and in a switching mode when the signal is at other voltages.

Abstract: Apparatus for substantially reducing the roll and pitch motions of a floating vessel in commonly occurring seas is described. The apparatus comprises a recessed cavity formed in a substantial area on the bottom of the hull of the vessel and has an airblower coupled to the cavity for introducing air into it. The apparatus may include horizontal planes for restoring the effect of the added mass of the water on the stability of the vessel.

Abstract: An improved feed horn for use with long f/D reflector antennae comprising an aperture having a plurality of protuberances orthogonally disposed around the periphery thereof, a conical section, a waveguide transition section and an impedance matching section.

Abstract: A seagoing vessel is stabilized by a passive system including tanks symmetrically disposed on the vessel below the water line. The tanks are connected by a conduit and pressurized with air to a selected pressure level. During each oscillatory roll and/or pitch cycle of the vessel, the tanks alternately fill and drain with selected volumes of water to reduce the righting moment of the vessel. The period of oscillation of the vessel is thus lengthened beyond the period of wave motion.

Abstract: This specification describes a power control circuit for reducing the brightness of multi-segment light-emitting diode (LED) characters in proportion to the number of segments illuminated to compensate for the apparent greater brightness of those characters having more segments illuminated than others. Since brightness is a function of power, the power required to drive multi-segment characters is substantially reduced, which extends useful battery life of battery powered equipment having light-emitting displays. Since less power is required by the display, the power driving and dissipation capability of the drive circuitry is also reduced.

Abstract: The circulating shift register time-keeping circuit of the present invention comprises five circulating shift registers and controller and time base circuits to provide real-time, stopwatch, date and alarm functions to an eight-digit display means via a display register. The real-time, stopwatch and date registers each include a binary adder, adder controller and auxiliary register coupled to clocked delay elements. The alarm register includes a comparator coupled to similarly clocked delay elements. Timing and command signals are provided to the five shift registers from the time base and controller, respectively.

Abstract: The thermal print head disclosed herein comprises resistive heating elements deposited on mesas of glass glaze over an aluminum oxide substrate for more efficient marking of thermally sensitive recording material. After the mesas are formed in the glass glaze by etching, resistive and conductive materials are deposited over the mesas by thin film techniques. Thereafter, the raised heater elements and conductors are delineated chemically, then heat-treated to upwardly adjust the resistance of and to grow a protective oxide over the individual heater elements. Since the resistance value of the heater elements can be controllably increased as a function of the temperature and time of heat treatment, external trimming resistors are eliminated.

Abstract: A battery-powered, hand-held calculator employs MOS/LSI calculator circuits to perform arithmetic and financial calculations. Data and commands are input to the calculator from a keyboard having a prefix key to double the functions of selected keys. A 15-digit, seven-segment light emitting diode (LED) display serves as the output for the calculator.

Abstract: Utilizing the method and circuit described herein regulated power is provided by controlling the duty cycle of p. fixed frequency signal as a function of the amplitude of unregulated D.C. voltage applied. A thin film thermal printer utilizing this power regulator is also described herein.

Abstract: A battery-powered, hand-held, calculator employs MOS/LSI calculator circuits to perform arithmetic and financial calculations. Data and commands are input to the calculator from a keyboard having shift key to double the functions of selected keys. A 15-digit, seven-segment light emitting diode (LED) display serves as the output for the calculator. The calculator circuits include a read-only memory circuit in which the algorithms for performing the arithmetic and financial calculations are stored; a control and timing circuit for scanning the keyboard, retaining status information about the condition of the calculator or of an algorithm, and generating the next read-only memory address; and an arithmetic and register circuit containing an adder, a group of working registers, a group of data storage registers forming a stack for roll down operation, and a constant storage register. These circuits are interconnected by a multiple line buss system.

Abstract: The quality of thermally printed characters is enhanced by controlling the time at which and the time for which power is applied to the resistive printing elements in a battery-operated moving-head thermal dot matrix printer. By sequentially strobing the elements in the pattern of the character to be formed as the print head moves across thermal sensitive paper, a high-quality slanted character is printed and parasitic losses are reduced. By inversely varying the time power is supplied to each dot as battery voltage varies, character quality is maintained and useful battery life is extended.