Abstract: A light sensor and light feedback adjustment device is provided for use with a control unit for selectively controlling the light output of at least one lamp of a ceiling-mounted luminaire to which the unit is connected, based at least in part on the level of ambient light feedback to the unit. The device includes a lens holder, a lens element screw-mounted on the lens holder and including a light gathering lens, and an arrangement for, in use, securing the lens holder in place in a ceiling tile of the ceiling on which the luminaire is mounted. The lens holder includes a tubular mounting portion including a central bore therein in which is disposed a fiberoptic bundle that receives light gathered by the lens. A light feedback adjustment arrangement includes an adjustable set screw mounted for movement in a transverse passage located in the lens holder between the lens element and the fiber optic bundle so as to vary the light coupled to the bundle.

Abstract: A control system is provided for controlling the average power from an alternating voltage source (AC) to a load having inductive properties. The system uses a synchronous switch shunted by a capacitor connected between the source (generator) and sink (load) to pulse duration modulate the AC voltage carrier wave. A control signal generator circuit drives the synchronous switch such that the switch is closed at a variable time early in each half-wave of the AC voltage source carrier wave and such that the switch is opened at a subsequent later, variable time during that half-wave. This is accomplished by sensing the voltage across the synchronous switch in order to inhibit closing of the switch early in the half-wave until the synchronous switch voltage (and thus the voltage on the capacitor) is substantially zero and then opening the synchronous switch at a point in time to give the desired volt-second area between closure and opening within each half-wave.

Abstract: A fluorescent lighting control system providing automatic and/or manual adjustability of the arc current(s) in one or more fluorescent lamps to permit operation of the lamps at less than rated wattage, and its concomitant luminous flux, in interior building spaces where full light output of the installed lamp(s) is rarely required particularly when daylight components are present. The goal(s) of this invention is to provide means to reduce wasteful electrical consumption in buildings and thereby reduce operating costs and gain the attendant benefit of dampening the increasing need for more electrical generation with its concomitant environmental pollution problem.

Abstract: A power controller is provided for controlling the average power provided from an AC voltage source power supply to an AC electrical load. Three shunt connected elements, comprising two electronic switches and a capacitor with rectifying diodes, are connected betwen the AC source and the load. A control circuit controls switching of the switches in timed relationship to the state of the voltage on the shunt capacitors so as to control the average power supply to the load. The control circuit switches one of the electrical switches to the conductive state thereof near the zero crossover of the AC wave of the source voltage and subsequently switches the second switch to the conducting state thereof at a variable time during each half wave in a manner that causes the first switch to return to the non-conducting state thereof.

Abstract: A low cost circuit addition in the form of a capacitor of suitable value provides effective starting and operation of rapid start, preheat, and instant start fluorescent type gas discharge lamps along with their standard A.C. operated ballast transformer auxiliary devices at reduced power levels to achieve energy conservation with a concomitant reduction in light output and can usefully employed in illuminated areas where a reduction in lighting level would not effect the utility of that particular area. The capacitor is connected in series with the ballast primary winding and is of such value as to cause ferro-resonance to occur in the ballast transformer primary circuit, thereby providing a voltage magnification effect to aid the lamp starting, or ignition, process i.e., during the time interval between circuit energization and production of a stable arc, and to thereafter operation of the lamp with reduced arc current.

Abstract: A method and apparatus are provided for operating a fluorescent lamp illumination control sytem which comprises an AC voltage source for supplying power to an electrical load comprising a standard transformer-ballast unit driving a fluorescent lamp or lamps which have externally heated cathodes, and a power controller, which includes a capacitive synchronous switch formed by an electronic switch and shunt capacitor, for controlling the "on" time of the lamp or lamps to thereby vary the luminance output thereof to values less than the nominal rated value. The invention provides heating of the lamp cathodes prior to arc ignition, provides arc ignition at a lower arc current level than that for full-on operation, and provides for subsequently gradually increasing the arc current after the arc is struck to a value providing the desired illumination level.

Abstract: An energy conserving lighting system is provided wherein a plurality of fluorescent lamps are powered by a poorly regulated voltage source power supply which provides a decreasing supply voltage with increasing arc current so as to generally match the volt-ampere characteristics of the lamps. A transistor ballast and control circuit connected in the arc current path controls the arc current, and hence the light output, in accordance with the total ambient light, i.e., the light produced by the lamps together with whatever further light is produced by other sources such as daylight. In another embodiment, a transistor ballast is utilized in combination with an inductive ballast. The transistor ballast provides current control over a wide dynamic range up to a design current maximum at which maximum the transistor is saturated and the inductive ballast takes over the current limiting function.

Abstract: A light regulation system is provided wherein the light output of a fluorescent lamp(s) is regulated in accordance with the RMS value of the lamp arc current which is automatically adjusted to maintain a referenced ambient light level or arc current. The ballast and associated lamps of the system receive the full line voltage until the lamps are ignited and thereafter the current thereto is automatically limited by limiting the amplitude of the ballast current during the part of each AC voltage half wave that the lamps are ignited. Control between the minimum light level, wherein a minimum arc current flows during each half cycle, to the maximum light level is accomplished by permitting the minimum arc current which flows during the "lamps on" period of each half wave to increase to maximum arc current over a part or all of the period of each half wave that the lamps are on.

Abstract: An electrical energy conservation control method and apparatus are provided which produce efficient control of the light output of either incandescent or fluorescent lamps or the outputs of other electrical load devices under circumstances where the rated output is not required. The control method and apparatus combines electronic (transistor) switching techniques with the use of reactive circuit components to provide control of the magnitude of current flowing through the load device during the AC input voltage sine wave and to permit some current flow at all times during each voltage half wave. The control technique is non-dissipative in the sense that losses are virtually limited to switching transitions and passive circuit element losses. The control is accomplished by controlling the time period that a transistor is saturated full-on.

Abstract: A light regulation system is provided wherein the light output of a second, fluorescent lamp fixture is regulated in accordance with the light output of a first or preceeding fluorescent lamp fixture. Each fixture includes a lamp or lamps, a ballast or ballasts and a control or regulating device which controls the ballasting of the lamp(s) of the fixture and hence the light output thereof. The system provides for monitoring the light output of the master fixture and optically coupling a corresponding signal to a photocell in the control device of the following fixture so as to control the output of the lamp(s) of the following fixture. Additional fixtures can be optically coupled in like manner to either the master or a follower fixture to provide additional controlled following fixtures.

Abstract: This invention relates to a method and apparatus for growing plant life under controlled conditions including gas discharge lamps with electronic means utilized to provide predetermined pulses of electric current to the lamps so that bursts of radiant energy are supplied to the plant life, these bursts of energy being of a duration in the order of microseconds and at a periodicity that is favorable to the plant growing processes. The radiant energy supplied to the plant life is within the spectral range required for photosynthesis and is uniform to the photoreceptors of the plant life.