Abstract: A high voltage active device such as a power FET is employed in a circuit configuration which maximizes the terminal impedance. This high impedance is placed in series with the gaseous discharge device to be driven. The gaseous discharge device is able to sustain conduction, between pulsed operations, at very low currents due to the very high impedance presented by the FET. A further refinement of the invention provides the supply voltage for the combination of the FET and the gaseous discharge device from a capacitor which can be charged during normal pulse-forming network charging.

Abstract: Methods and apparatus are disclosed for supplying and controlling simmer current to a flashlamp 28. A direct current-to-direct current converter including a transformer 12, full-wave bridge rectifier 24, and first and second switching means 20 and 22 produces an output which is always higher than the maximum required by the flashlamp 28 at its lowest simmer current. The converter (12, 20, 22, 24) is coupled to flashlamp 28 through an inductor 26. The current I(s) through a pair of inductors 26, 30 is sensed by a lamp current sensing circuit 34 which turns the converter on or off, respectively, when a preselected minimum or maximum value is reached. The converter transformer 12 is maintained in its operating range by the switching of two devices such as power FET's 20, 22 so that one or the other of the two halves of the primary winding 14 is used alternately. The initial ionization of flashlamp 28 is provided by simmer trigger circuit 38.

Abstract: A power supply (20) incorporates a switching regulator circuit and a flyback transformer (26) having diodes (42) for unidirectional current flow from an output circuit of the transformer to a load (24). Substantially noise-free sensing of currents in both input (32) and output (34) windings of the transformer is provided by a sensing circuit composed of a sense winding (46) on the transformer and an integrator (50) coupled to the sense winding. The integrator provides an output signal proportional to volt seconds or flux which, in turn, is proportional to either the input current or the output current. The input current and the output current flow alternately due to a switching action of the regulator circuitry.

Abstract: In a power supply having transformer coupling for regulation of voltage by a pulsing of primary current, a control circuit integrates the output voltage to obtain a measure of flux and primary current. A comparator monitors the integrated voltage to terminate a pulse of primary current prior to saturation of a core of the transformer. This insures linear operation and efficient transfer of energy from the primary to the secondary windings of the transformer. A sensor of secondary current initiates a new pulse of primary current when the secondary current has decayed to a fractional value of the peak secondary current.

Abstract: A system for generating data for input to a computer representing the length of time the worker has spent at a workstation performing a task includes portable memory circuit, a data entry circuit, and a data reading circuit. The memory circuit stores data relating to the task. The data entry circuit is located at the workstation and is adapted to electrically connect to the memory circuit and automatically and periodically writes into the memory circuit data program into the entry circuit which relates to the task at the workstation. The data reading circuit is electrically connected to the computer and is also adapted to electrically connect to the circuit. The data reading circuit transfers into the computer the data written into the memory circuit by the data entry circuit.

Abstract: This invention is an improved ranging system including an improved digital single shot circuit that has a resettable shift register therein so that a signal representative of the last target return occurring at any point of a predetermined range interval will be provided to the timing counter of the system. The digital single shot circuit includes a flip flop responsive to the first trigger pulse during the predetermined range interval, resetting the shift register so that, when the output pulse from the shift register representing the last target return is applied to the timing counter, it will terminate a fixed number of clock edges after the last trigger pulse determined by the number of stages of the shift register. The fixed delay in terminating the output of the shift register may represent the preset time of the readout counter.

Abstract: A flyback type power supply in which dissipation losses associated with switch transition time are substantially eliminated by performing all switching operations at or near zero current by the use of a plurality of resonant circuits. In a first resonant circuit an intermediate storage capacitor is resonantly charged through an inductor and a first switch until, after a half sinewave of charging current, the voltage on the capacitor is twice the input supply voltage. The capacitor is then discharged through a second switch and the primary inductance of a flyback transformer having rectifiers on the secondary that are back-biased initially so as to provide a resonant current buildup in the primary winding with an amplitude that follows a sinewave function, the primary voltage following a cosine function.

Abstract: A pulse generator adapted for providing electrical pulses to a reactive load circuit. First and second energy storage circuits are coupled to the reactive load circuit and to each other by means of switching devices such that energy initially stored within the first energy storage circuit is sequentially circulated to the reactive load, then to the second energy storage circuit and back to the first energy storage circuit. In accordance with a second embodiment of the invention which is especially adapted for high repetition rate applications, a plurality of the above described pulse producing circuits are coupled in parallel and are controlled to operate in multiphase operational cycles so that each section produces one output pulse during each operational cycle.