Abstract: A power supply includes a coupled inductor having a primary winding, a secondary winding and a feedback winding. A rectifier/filter is coupled to the secondary winding for supplying the load with a DC current. A power switch is coupled in series with the primary winding for switching between conductive and non-conductive states to control the flow of current through the primary winding. A first drive circuit applies a first drive signal to the control lead of the power switch for switching the power switch into the conductive state. A primary current sense circuit generates a primary current feedback signal representative of the primary winding current. An output current sense circuit generates an output current feedback signal representative of the power supply output current. A programmable reference voltage generator generates a DC reference voltage having a magnitude determined by the output current feedback signal.

Abstract: A strobe trigger pulse generator includes a power supply, an energy storage capacitor coupled to the power supply and a trigger pulse generator which intermittently energizes a trigger pulse transformer to ionize the gaseous interior of a strobe flash lamp. The trigger pulse generator includes a trigger capacitor coupled to the trigger pulse transformer. A trigger capacitor charging device is coupled between the power supply and the trigger capacitor to selectively direct a charging current to the trigger capacitor. The trigger capacitor discharge circuit is coupled to the trigger capacitor to periodically discharge the capacitor through the trigger pulse transformer to generate a high voltage trigger pulse. A charge path disabling circuit is coupled to the current flow path between the power supply and the trigger capacitor to control the charging current directed to the trigger capacitor.

Abstract: The DC to DC converter includes a coupled inductor having a primary winding and a feedback winding. A drive current regulator circuit receives a variable input voltage from the feedback winding but transmits a constant base drive current to the base terminal of the converter switching transistor. The base drive regulator circuit thereby enables the DC to DC converter to operate at high levels of efficiency over wide ranges of DC input voltages such as twelve to forty-eight volts DC.

Abstract: A light fixture includes a parabolic reflector, a light source positioned at the focal point of the parabolic reflector and a lens assembly. The lens assembly includes a front lens for transmitting the primary beam reflected from the parabolic reflector. The lens assembly also includes a first lens section including one, two or more lateral focussing elements positioned between the front lens and the edge of the parabolic reflector to intercept omnidirectionally radiated light rays from the light source and to redirect the intercepted light rays into collimated lateral beams to illuminate selected areas at the side of the light fixture.

Abstract: A strobe trigger pulse generator includes a power supply, an energy storage capacitorcoupled to the power supply and a trigger pulse generator which intermittently generates trigger pulses to energize a trigger pulse transformer. The pulse generator includes a trigger capacitor having first and second leads, the first of which is coupled to the trigger pulse transformer. A trigger capacitor charge circuit includes an input terminal coupled to the power supply and an output terminal coupled to the second lead of the trigger capacitor to establish a current flow path between the power supply and the trigger capacitor to direct a charge current to the trigger capacitor. A trigger capacitor discharge circuit is coupled to the second lead of the trigger capacitor to periodically direct a discharge current from the trigger capacitor through the trigger pulse transformer to generator a high voltage trigger pulse.

Abstract: A light fixture includes a parabolic reflector, a light source positioned at the focal point of the parabolic reflector and a lens assembly. The lens assembly includes a front lens for transmitting the primary beam reflected from the parabolic reflector. The lens assembly also includes a first lens section including one, two or more lateral focussing elements positioned between the front lens and the edge of the parabolic reflector to intercept omnidirectionally radiated light rays from the light source and to redirect the intercepted light rays into collimated lateral beams to illuminate selected areas at the side of the light fixture.

Abstract: An optically transmissive, substantially cylindrical enclosure surrounds a light source. A generally circular base includes a vertically oriented first flange section dimensioned to fit coaxially within a vertically oriented lower section of the enclosure. The base includes a horizontally oriented, second flange section coupled to the first flange section and oriented perpendicular to the longitudinal axis of the lightining fixture. A circular clamp compresses a resilient gasket between a lower, horizontally oriented surface of the enclosure and the horizontally oriented second flange section of the base to create an hermetic seal between the base and the light fixture enclosure.

Abstract: A light source is positioned within a substantially cylindrical, optically transparent enclosure having a load supporting base. The exterior surface of the enclosure includes a light converging lens having a plurality of jagged edges subject to contamination by dirt and moisture. An optically transmissive, substantially cylindrical secondary cover having a smooth exterior surface is coaxially fitted over the first enclosure to protect the jagged elements of the enclosure lens from contamination by dirt or moisture. An hermetic seal is formed between the lower, outer surface of the lens and the lower, inner surface of the secondary cover to prevent introduction of either dirt or moisture into the chamber formed between the exterior of the lens and the interior of the secondary cover.

Abstract: The converter delivers current to an intermittently energized load and includes a coupled inductor having a primary winding, a secondary winding and a feedback winding. A switching transistor is coupled in series with the primary winding of the inductor and switches between conductive and non-conductive states to control the flow of current through the primary winding. A positive drive circuit provides positive bias voltage to the switching transistor. A current limiting circuit senses the voltage across the base-emitter junction of the switching transistor to measure the primary winding current, removes the positive bias voltage when the primary winding current reaches a predetermined value, and thereby switches the transistor out of the conductive state into the non-conductive state.

Abstract: An overvoltage protection circuit limits the output voltage of a DC to DC converter to a maximum desired output voltage. An output voltage sensing circuit includes a semiconductor device such as a sidac having a normal resistive region of operation as well as a negative resistance region of operation which begins at a breakover voltage and extends into a foldback region. One terminal of the sidac is coupled to sense the converter output voltage while the second terminal opposite end of the sidac is coupled to a biasing device in the form of a resistor which generates an overvoltage signal when the sidac conducts current. The overvoltage signal from the biasing resistor is coupled to a converter switching transistor disabling circuit which reduces the converter output voltage to a level below the maximum desired output voltage in response to the overvoltage signal.

Abstract: The DC to DC converter includes a coupled inductor having a primary winding and a feedback winding. A drive current regulator circuit receives a variable input voltage from the feedback winding but transmits a constant base drive current to the base terminal of the converter switching transistor. The base drive regulator circuit thereby enables the DC to DC converter to operate at high levels of efficiency over wide ranges of DC input voltages such as twelve to forty-eight volts DC.

Abstract: A variable frequency DC to DC converter generates a pulsed, variable magnitude output voltage where the frequency of the pulsed output voltage varies with changes in the magnitude of the output voltage. An energy storage capacitor is coupled between the converter coupled inductor and strobe flash lamp or other gaseous discharge tube and is periodically discharged through the flash lamp. A variable impedance device in the form of a capacitor is coupled in series with the flow of current from the coupled inductor into the energy storage capacitor to provide a low impedance current flow path when energy is transferred from the coupled inductor into the capacitor and to provide a high impedance current flow path between the converter DC voltage input terminals and the energy storage capacitor when energy is transferred from the capacitor into the strobe flash lamp.

Abstract: The operation of a strobe lighting system is electronically monitored from a remote location to verify proper operation of all of the individual elements of the system. A current sensor is coupled in series with the flow of current between the strobe power supply and the strobe lamp and generates a voltage pulse in response to each flash inducing pulse of current through the strobe lamp. A remote indicator is coupled to the current sensor and generates a humanly perceptible output signal (visual or audible) in response to the voltage pulse from the current sensor. The strobe flash monitor enables a strobe lighting system user to continuously monitor system operation without direct observation of the strobe lamp flashes.

Abstract: The converter delivers current to an intermittently energized load and includes a coupled inductor having a primary winding, a secondary winding and a feedback winding. A switching translator is coupled in series with the primary winding of the inductor and switches between conductive and non-conductive states to control the flow of current through the primary winding. A positive drive circuit provides positive bias voltage to the switching transistor. A current limiting circuit senses the base voltage of the switching transistor to measure the primary winding current, removes the positive bias voltage when the primary winding current reaches a predetermined value, and thereby switches the transistor out of the conductive state into the non-conductive state. A negative drive circuit is coupled between the feedback winding and the base of the switching transistor and supplies a constant negative bias voltage to the transistor base as energy is transferred from the inductor into a load.

Abstract: A vehicle to loading dock releasable locking unit includes a hook for engaging a coupling on the vehicle, a motorized drive system for rotating the hook back and forth between locked and unlocked positions, and a hook position sensor for sensing whether the hook is in the locked, the unlocked or an unsafe position between the locked and unlocked positions. The automatic control system includes a hook position selector for generating lock or unlock signals in response to a hook position command selected by an operator and for storing the selected hook position command. A first actuator control unit energizes the hook actuator to reposition the hook into the locked position in response to the lock signal. A second actuator control unit energizes the hook actuator to reposition the hook into the unlocked position in response to the unlock signal.