Abstract: A lighting control system is provided which utilizes a light responsive sensor means and a control system to respond to the skylight illumination while rejecting direct sunlight as a control parameter. The skylight illumination level is used to control lighting power controllers that can dim interior lighting equipment in a defined pattern to maintain a uniform light level at a work surface and to conserve electrical energy.

Abstract: A portable light for emergency illumination which is activated in response to the sound emitted by a smoke alarm device. The circuit is highly simplified, making it producible in quantity, and has a performance which is highly predictable. The circuit has a very low battery drain so that it will operate from a small battery for a period of years. The circuit is highly insensitive to extraneous noise signals and utilizes the normal drop in battery voltage when the light comes on to prevent the circuit from going into an oscillation mode.

Abstract: A dimming circuit for a discharge lamp (5) arranged in series with two electric coils (3, 4), one of which is by-passed by a semiconductor switching element (6).The control circuit of the semiconductor switching element (6) includes a series arrangement of a resistor (15) and a capacitor (16) connecting a main electrode to the control electrode. The inductance of the by-passed coil (3) is chosen such that the semiconductor switching element (6) is made conductive on reignition of the lamp. The electric losses of the dimming arrangement are low.

Abstract: The present invention provides an electric flash apparatus which comprises power supplying means, trigger signal generating means, flashlight generating means, trigger signal controlling means for controlling the trigger signal generating means and flashlight quantity control means for adjusting automatically the light quantity of the flashlight. The electric flash apparatus of the invention can operate as a mono-flashing device and as a multi-flashing device, and the electric flash apparatus of the invention further can control quantity of the flashlight of a flash tube in both of the mono-flashing operation and the multi-flashing operation, in spite of the photographing distance.

Abstract: The single zone lighting controller controls the lights in a zone or area integrating external control signals for daylighting and occupancy with a local override function. The daylighting signal is from a master photoelectric control, and occupancy signal is from a time-clock or electronic occupancy sensor; the local override, activated by an occupant provides a fixed override period before the single zone lighting controlled again responds to the external control signals. Shortly before the override period is over, the single zone lighting controller warns the occupant, e.g., by blinking the lights that the override is about to end.

Abstract: A control for an outdoor lighting fixture which adds an extra off-on cycle to that imposed by a photoelectric cell control. At a predetermined time during the on period of the lighting fixture, the lamp of the fixture is shut off. This shut-off time had previously been determined as one during which traffic in the area is at a minimum. A set time after the shut off, the lamp is lit once again, this time being selected as a time when traffic is re-appearing. When the ambient light reaches the shut-off level of the photoelectric cell, the lamp is shut off for the day. In this way, the lamp is turned off for a timed period for the purpose of reducing the energy required by the lamp for the dark hours of the night.

Abstract: A motion detection system is disclosed which utilizes a lens or other imaging device to be responsive to motion in a particular field of view in a room, for example, and pass illumination to a photocell. The photocell or a screen in front thereof establishes image distortion so that there is a nonuniform electrical output from the photocell upon motion of objects in the given field of view. The nonuniform electrical output establishes pulses which are passed to a timer and continually resets the timer so long as there is motion detected. Upon discontinuance of any motion in the field of view, no further pulses are passed to reset the timer, and the timer times out to de-energize an electrical load. This may be an electrical lamp illuminating the field of view, or it may be an electric soldering iron or typewriter which is de-energized when the person has left the room.

Abstract: An illumination control device controls the level of artificial lighting depending upon the intensity of natural light in the area being controlled. A single adjustment is used to set the switching point at which the illumination control device becomes operative. An indicator is provided to indicate the adjustment status before a change in the artificial light condition occurs. A filter is employed to produce turn-on and turn-off time delays which differ from one another and are automatically changed in accordance with the instantaneous light level which exists prior to a necessary circuit switching operation.

Abstract: A circuit is provided for regulating the application of power to a load which is relatively insensitive to rapid power fluctuation of the type exemplified by typical AC line sources. In one embodiment, an AC line source is applied at a controlled rate to a tungsten lamp whose operation is controlled by a transistor switching network. The transistor operation, in turn, is controlled by comparing a portion of the rectified signal with a signal proportional to the light output of the lamp.

Abstract: A light source apparatus which comprises a flash discharge tube for illuminating a foreground subject, a switching element connected in series with the flash discharge tube, a light receiving circuit for photoelectrically converting light reflected by a foreground subject to produce a signal corresponding to the amount of light reflected from the received foreground subject and a decision circuit for producing an interruption signal for rendering the switching element non-conductive with partially as a function of the output signal of the light receiving circuit. A correction circuit for producing a correction signal in accordance with a preset film sensitivity is further provided. The decision circuit produces the interruption signal when the difference between the output signals of the correction circuit and light receiving circuit is reduced to zero.

Abstract: An electronic flash device having a battery, means for converting the battery voltage to alternating current voltage, means for rectifying the alternating current voltage to direct current voltage, a main storage capacitor charged by the direct current voltage, a flash tube in parallel with the storage capacitor, a trigger circuit for firing the flash tube and a control circuit for stopping the flash operation of the flash tube when a predetermined amount of light has been reflected from an object to be photographed. The control circuit is actuated by a light measuring circuit which senses the reflected light. A switch element connects the light measuring circuit to the battery during activation of the flash tube.

Abstract: An energy conserving circuit for controlling supply of electrical power to various loads such as a street lamp or a hot water heater comprises a photoelectric device for starting a timer when a change from daylight to dark is sensed at sundown, and a load power control responsive to the timer to switch between power-off and power-on states. With a street lamp the timer and power control means are connected to switch the power control means to power-on state at the beginning of the delay period at sundown and later, well before sunrise, to switch to power-off state. In the case of a household hot water heater the switching of the power control to power-on state is delayed until the peak demand hours have ended after sundown. The photoelectric device will normally cause the power control to switch to power-off state at sunrise.

Abstract: A motor-car headlight with a built-in static relay.The headlight lamp is connected in series with a power phototransistor with which it is optically coupled. Turn on and turn off of the phototransistor is effected by temporarily changing the base voltage.

Abstract: A photosensitive switch including control means for turning a load on or off in response to the ambient light level. The switch is so arranged to turn the load off if the components thereof fail.

Abstract: Switching apparatus for energizing a load from an a.c. current source where the apparatus is actuated to an "on" condition by the application of a source of light, such as a match. A photo-responsive, solid-state element such as a light actuable SCR is mounted within the apparatus at the end of a passageway of length and width selected to preclude an influence of ambient lighting. The "on" condition of the device is sustained through the utilization of a feedback light path, the source of which is an incandescent lamp. Switching "off" the apparatus is carried out by blowing on an opaque flap from a rest to a transient position temporarily blocking the feedback light path.

Abstract: A switch for controlling the operation of a light source in response to the presence of a moving person or object and in response to the magnitude of ambient light provided other than by the light source, said switch comprising means for detecting the presence of a moving body; timing means responsive to said detecting means, said timing means assuming a first condition for a selected period of time in response to the detection of a moving body by said detecting means; means for monitoring the magnitude of ambient light, said monitoring means assuming a first condition when the magnitude of ambient light is below or at a selected value and assuming a second condition when the magnitude of ambient light is above the selected value; and means for actuating a light source only when said timing means is in its first condition and when said monitoring means is in its first condition.

Abstract: A traffic light control circuit of the type utilizing solid state thyristor switches with their control terminals driven by a diode bridge trigger network that includes switches for selectively interrupting one or both legs of the trigger network for energizing the traffic lights with either full wave power for normal daytime operation or half-wave power for night time operation at reduced brightness, thereby providing power savings for night time operation.

Abstract: An energy-conserving solid-state-controlled illumination system which operates high-intensity-discharge lamps. The system operates the lamps at about a predetermined rated power consumption with a relatively high light output for a predetermined initial period of time during the initial night when a high degree of illumination is most needed. The system then operates the lamps for a later period of the night at a reduced power for a second predetermined period of time when a lower degree of illumination can be tolerated. Then if the lamps are still energized according to seasonal variations, the system thereafter operates the lamps at the relatively high light output for the remainder of the night to accommodate early morning traffic.

Abstract: A device for activating an electronic slave flash unit for photographic use includes a circuit wherein there is a delay circuit responsive to a light sensing signal after a predetermined time delay to activate a flash unit. The time delay of the delay circuit is adjustable as required, and the delayed operation of the flash of the slave flash unit eliminates incorrect impulse signals being transmitted to light sensors of other slave flash units which would otherwise prematurely extinguish their flash and give a resultant incorrect lighting effect. The power for the circuit is obtained from a capacitor which is energized by a flash unit. The energy in the capacitor is used to power the delay circuit, and a Zener diode and unijunction transistor and variable resistance permit accurate variable time delays.

Abstract: A digital room light controller comprising optical emitters--sensors, a digital up/down counter, associated transistor--transistor logic(TTL) and solid state relay(SSR) has been constructed. The combination of optical emitters--sensors, TTL logic, up/down counter and SSR, which, when positioned in a doorway of a room, will maintain an electric light bulb in an on or off state depending on the accumulated count in the counter. The digital light controller increments the total count by +1 (i.e. counts up) in the counter when the room is entered and increments the count by -1 (i.e. counts down) when an exit is made from the room. A count of zero causes the interruption of electric power at a selected light fixture, while a non-zero count in the counter insures the maintenance of electric power at the fixture. Therefore a room light is maintained in an off state when the room is not in use.

Abstract: A control circuit for flash tube apparatus has a flash tube, a thyristor for controlling the flash tube in ON-OFF fashion, a trigger circuit for triggering the flash tube and thyristor, a commutation capacitor for turning the thyristor OFF, a switch circuit for supplying a charge stored in the commutation capacitor to the cathode-to-anode path of the thyristor. The control circuit further includes a trigger blocking circuit connected between the trigger circuit and the gate of the thyristor, a carrier recombination capacitor connected in parallel with and across the gate and cathode of the thyristor, and a timer circuit for operating the trigger blocking circuit for a predetermined time period. The thyristor is turned ON by a trigger pulse TP2 from the trigger circuit. When the switch circuit is rendered ON, the timer circuit is operated. The trigger blocking circuit blocks the trigger pulse until the discharge of the commutation capacitor is completed.

Abstract: A smoke alarm activated portable light or lamp for providing emergency illumination in response to an alarm signal from a smoke alarm device includes a frequency selective microphone, several amplifier stages, a peak detector, an isolation or buffer stage, and a power stage comprising a pair of cascaded transistors and a light bulb. The lamp includes a bracket for positioning same in proximity to a smoke alarm and a switch which is closed upon removal of the lamp from the bracket. A power saving circuit includes a photoelectric cell and an amplifier and is operative to saturate or overdrive the first gain stage to override any signal from the microphone whereby the lamp is rendered unresponsive to the smoke alarm signal upon illumination of the photocell by daylight or artificial light.

Abstract: Circuitry for digitizing received light into a digital pulsating signal, including a photodiode operable in response to light intensity for passing current to a capacitor for developing a voltage level thereacross. A voltage comparator with a hysteresis responds to the magnitude of the capacitor voltage level for tripping the comparator's output between a HIGH and LOW state which directs capacitor discharge to cycle the comparator output in a pulsating manner.In a preferred embodiment, the circuitry is powered by a flash storage capacitor along a pair of conductors which serve both to power the circuitry and to receive pulsating current levels indicating voltage comparator switching. The current levels are sensed and counted for producing a binary count output of received light energy. In another embodiment, the conductors also serve to carry a trigger signal for directing flash initiation.

Abstract: A light activated control system, particularly for operating warning lights on a vehicle parked at night. The system includes a light sensor mounted on the vehicle and a comparator which triggers a time delay threshold device which switches on the warning lights for a predetermined period of about ten seconds only when the sensed light intensity increases through a threshold level due for example to the approach of a lighted vehicle. The system may alternatively be responsive to the rate of increase of sensed light level to switch on the warning lights.

Abstract: The invention relates to a power supply system for a semiconductor light source of which the power is regulated in the steady state by a regulating loop comprising an electronic switching circuit controlled by a signal characteristic of the power emitted by the laser which closes the regulating loop when the output power has reached, a threshold power, a ramp generator supplying a ramp of current to the laser solely from the instant when the feed voltage is established for reaching the threshold.

Abstract: The present invention relates to a system for energizing flash-tubes of beacons by means of the capacitive energy extracted from an insulated section of the overhead wire of power transmission lines. The supply system comprises a circuit for transforming the AC capacitive energy from the overhead wire into DC voltage, the latter feeding at least one flash-tube and a regulation circuit shunted across the transforming circuit for controlling a DC voltage threshold value supplying the tubes. Such regulation is achieved by detecting the predetermined DC voltage threshold value across the lamp terminals and by switching to the earth any capacitive energy extracted from the overhead wire exceeding that threshold value. Moreover, a circuit delivers a pulse at predetermined time intervals to control the firing of each flash-tube when the latter is subjected to a DC voltage corresponding to the predetermined threshold value and regulated by shunt switching.

Abstract: A lighting system for illuminating a given area is disclosed herein and includes a number of luminaires, each having a light source and a light sensitive device for automatically connecting the light source to a supply of power during the dark hours of the night and for automatically disconnecting the light source during the light hours of the day. This system also includes light control circuits associated with some but preferably not all of the luminaires. Each light control circuit overrides the operation of an associated light sensitive device and automatically disconnects its light source from the power supply for a predetermined period during the dark hours at a time when it is not important to provide a high degree of illumination, for example in the middle of the night.

Abstract: A light detecting and measuring device for use with an electronic flash unit comprises a phototransistor, integrating capacitor and diodes connected in circuit to the flash unit. The diodes and capacitor are connected to the phototransistor and responsive to signals from the flash unit for enabling measurement of light by the phototransistor only while the flash unit is operating thus preventing measurement from external light sources.

Abstract: A lamp control circuit having a heater and thermistor coupled between the illumination sensitive device and the control electrode of an SCR or triac for providing a time delay between the detection of a change in illumination and the switching of the SCR or triac.

Abstract: An electronic flash of the type incorporating the so-called variable guide number device or a flash duration control device for controlling the quantity of a flash of light emitted from a flash lamp. In an integrating circuit of the variable guide number device diodes are used so that their forward bias characteristics may be utilized for the accurate control of a flash duration.

Abstract: A photocell-controlled lighting system is disclosed. The system comprises a first photocell-controlled operated by a photocell, at least one night or decorative light adapted to be connected to a power source, at least one spotlight, also adapted for connection to the power source, a second relay adapted for connection to the power source and responsive to energization of the photocell-controlled relay for energizing the night or decorative light and to de-energization of the photocell-controlled relay when the photocell is illuminated by the lights of an automobile entering the driveway of a house for switching off the night or decorative light, and a third time relay adapted for connection to the power source and operated by the second relay when the lights of the automobile are switched off for switching of the spotlight for a predetermined time interval.

Abstract: An ignition circuit is provided for extinguishing tubes in electronic flash equipment for photography. The second winding of an ignition transformer is arranged in series to the extinguishing tube. A diode is connected in parallel to the secondary winding of the ignition transformer through which the extinguishing tube current flows after ignition. The extinguishing tube does not require an ignition electrode. The ignition circuit is advantageously employed in electronic flash equipment for photography having an automatic circuitry for control of flash luminance time.

Abstract: An auxiliary electronic flash apparatus coactuable with a main electronic flash apparatus of the type having a first flash lamp for converting the energy stored on a first main capacitor into light for illuminating a subject, and a control circuit for turning off the first flash lamp when the light emitted from the first flash lamp and reflected back from the subject reaches a predetermined amount. The auxiliary electronic flash apparatus includes a photometric circuit responsive only to the light emitted from the first flash lamp within a predetermined light wavelength range for generating a flash start signal in response to which a second flash lamp in the auxiliary electronic flash apparatus is turned on and for generating a flash and signal in response to which the second flash lamp is turned off.

Abstract: An electronic flash apparatus comprises a discharge circuit and termination circuit for terminating the discharge circuit. The discharge circuit comprises an energy storage capacitor and a series circuit formed of a flash tube and a first switching element connected in parallel to the energy storage capacitor. The first switching element is rendered inoperative by a reverse voltage which is temporarily supplied when energy stored in a commutation capacitor of the termination circuit is discharged by a second switching element. When a prescribed period of time has passed after the first switching element is turned off, the switching element is again put into operation by a retrigger circuit. The commutation capacitor is reversely charged through the flash tube after the first switching element is turned off. The reverse charge is discharged by the retrigger of the first switching element.

Abstract: A modular lighting control apparatus utilizes a housing having a plurality of total electric light centers mounted therein, such that the centers may be manually activated by light beams emanating from a hand held flashlight. The housing is provided with a utility outlet receptacle and is operated by a flexible line cord which is energized by a household utility current. Each light sensor controls a character of the outlet voltage available at the output receptacle. One light sensor provides a source of continuous full voltage at the light receptacle. Another light sensor de-energizes the voltage supply to the output receptacle. Still another light sensor causes the voltage, present at the output receptacle, to become intermittent. Yet another light sensor determines the amount of voltage available at the output receptacle.

Abstract: A photocell illuminated by the projection lamp of a slide projector controls a spring-biased longitudinally movable lamp exchange carrier. Lamp failure causes a change of state in the photocell that electronically releases an electromagnetic lock and allows the spring-tensioned lamp carrier to change positions. The last spare lamp is screened from the photocell, causing the electronic circuit to energize a fluorescent diode to indicate that the last spare lamp is being used.

Abstract: A system for automatically controlling actuation of various parts of an automobile in accordance with various sensed conditions. Four photocells are mounted, preferably about the periphery of the courtesy light inside the automobile on the roof, to receive ambient light from four orthagonal directions and are connected to a logic circuit to produce a signal causing the automobile's lamps to be turned off only when all four of the photocells are sensing daytime conditions and to be turned on, after a short delay, when any of the photocells senses nighttime conditions which persist during the delay. A water cell is mounted at the base of the windshield so that during a rain shower the water cell will become conductive. The water cell is also connected to the logic circuit and to a motor driver circuit, which signal produced by the conductive water cell causing the lights and windshield wipes to be actuated as long as the shower continues.

Abstract: The flash unit includes a flash element and a first electronic switch connected in the current path of the flash element. The flash element is ignited by rendering the first switch conductive. Flash-terminating circuitry terminates the flash by rendering the first switch non-conductive. The flash-terminating circuit includes a commutation capacitor and a second electronic switch interconnected with each other and with the first switch for applying the commutation capacitor voltage to the first electronic switch as a reverse-bias voltage when the second electronic switch is rendered conductive. The second electronic switch is a two-electrode electronic switch which can be rendered conductive by raising the voltage across its electrodes above the value at which such voltage is normally maintained.

Abstract: A low-pressure sodium vapor discharge lamp and a current stabilizing ballast element are connected in series to an energy source so that the lamp is operated by means of a non-sinusoidal current. The temperature of the wall of the discharge tube is maintained in an accurately defined interval and the instantaneous current density in the tube is kept below a first given value and the effective current density is kept above a second given value. This results in a relatively high luminous efficacy.

Abstract: An automatic flash-limiting arrangement for use in combination with a flash unit associated with a camera and arranged to automatically terminate the light flash produced by the unit when the subject has been properly exposed, the flash-limiting arrangement being associated with the flash unit so as to become operative only upon initiation of a light flash, thus assuring that the arrangement will not respond to extraneous flashes occurring before the flash which is to be controlled. The flash-limiting arrangement is constructed to sense the light being received by the camera, to produce a signal which is the sum of a component proportional to the time integral of the intensity of such light and a component which is proportional to the instantaneous amplitude of the intensity of such light, and to terminate the flash when this signal reaches a predetermined value.

Abstract: Pulse operating circuit for high intensity gaseous discharge lamps is provided with improved lamp starting device. The circuit comprises a direct current supply, a transistor switch in series with a ballast inductor and a lamp across the DC supply, an SCR switch connected across the inductor, a control circuit connected to the transistor switch for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle, a sensing circuit for sensing the voltage across the inductor, and a variable SCR firing control circuit connected to the SCR and the first mentioned control circuit and responsive to the sensing circuit to control the firing of the SCR for limiting the peak current through the transistor switch during the lamp starting and warm-up interval.

Abstract: The trigger circuit of an electronic flash device includes a pulse transformer connected to a trigger electrode of a flash tube, a capacitor connected to the pulse transformer, a thyristor connected in the discharge path of the capacitor, and a control circuit for the thyristor. This control circuit is provided with a low-voltage trigger means for applying a trigger pulse to said thyristor and further with a synchronous switch connected therein so that the synchronous switch operates with a low voltage.

Abstract: An ambient light responsive switch for street lamps or other loads, includes a thermostatic switch of the thermal time delay relay type, connecting a load to a current source and exposed to a heater resistor and snap opening and closing at relatively high and low temperature values. An ambient light exposed photoconductor, a first resistor and the heater resistor are series connected across the current source, and the first resistor and a second resistor are series connected across the switch. With the closing of the switch in response to a low light value the load is energized and the resistance in series with the heater resistor is accordingly lowered to increase the heater current. With the opening of the switch in response to a high light value the load is deenergized and the resistance in series with the heater resistor is accordingly increased to decrease the heater current and reduce the sensitivity of the switch.

Abstract: An electronic flash unit for photographic purposes, with improved means for quenching the flash when sufficient light has been emitted from the flash tube. The discharge circuit of the main storage capacitor comprises the flash tube and a switch thyristor in series with each other. A quench circuit including a quenching capacitor and a quenching thyristor will deliver a quenching current to the switch thyristor when the quenching thyristor is triggered by exposure metering and flash limiting mechanism, this mechanism including a resistor, a phototransistor, and an integrating capacitor in series with each other and in parallel with a feed capacitor which supplies feed current to the exposure metering and flash limiting mechanism, and which is in parallel with the switch thyristor.

Abstract: A circuit is disclosed which is suitable for controlling lighting in a building from a multiple number of points. AC current to light bulbs is controlled by a triac which in turn is controlled by the output of an optical coupler which is controlled by the output of a logic device. The output of said logic device is connected to control the input to the triac. Switches connecting to the input of the logic device each can independently determine energization or deenergization of the light bulbs.

Abstract: An improved trigger circuit for triggering an electronic flash apparatus and for energizing a remote sensor is disclosed.

Abstract: The invention relates to an electronic flash device which is provided with a series arrangement of an electronic flash tube and a thyristor, which flash device is equipped with a flash duration limiter (computer electronic flash device).According to the invention a rectifier is connected anti-parallel to the thyristor. As a result a smaller thyristor can be used, while the energy consumption can be reduced and an unwanted "light spike" at the end of the flash duration can be avoided.

Abstract: An electronic flash unit having the conventional flash tube, storage capacitor dischargeable through the flash tube, measuring device for recording the quantity of light emitted by the flash tube and reflected back from the subject being photographed, a pulse generator responsive to the measured reflected light, and means for quenching the flash in response to a pulse produced when the measured reflected light reaches a threshold value. The present flash unit, in addition to the conventional features just mentioned, includes the novel feature of a light-emitting diode which becomes illuminated when the light measuring means and the pulse generator circuit become operative, thus signalling to the user of the device that the so-called "computer" mechanism has actually operated. Circuit means is provided for extinguishing the light-emitting diode at the proper time.

Abstract: Circuits and auxiliary elements for use with a device for controlling the emission of light pulses from a flash unit, which light pulses are produced by the discharge of current pulses from a capacitor, the device including a light sensing element for receiving light produced by the flash unit and reflected from an object in the light path. One such circuit includes a switch which is selectively operable to permit control of termination of the emission of light pulses at either one of two light intensity output levels. Another circuit permits one light sensing element to normally trigger the emission of a light pulse in response to a light pulse from a remote unit, and to be selectively connected to subsequently control termination of such emission. One such element is a special gas filled switching tube having two internal electrodes for triggering conduction through the tube in response to a low voltage.

Abstract: A circuit for controlling the energization of a night lighting load or the like, in which failure of the main circuit to control and shut off electrical supply to the load during daylight hours leads to permanent shutdown of the electrical supply to the load. Two photosensitive elements are provided in the circuit. One element, e.g. a photocell, is a main control which periodically operates a relay and supplies electricity to the load, i.e. at night. The second element, e.g. a second photocell, is connected in the circuit, together with a second relay, in such a manner that failure of the first relay to operate and open the load circuit during daylight hours will cause the second relay to operate and permanently open the load circuit.