Abstract: A ballast apparatus for series-sequenced gaseous discharge devices includes at least one pair of series-sequenced discharge devices having series-connected filaments with a first rectifier means coupling a filament of one discharge device to the transformer and a second rectifier means coupling the series-connected filaments to the transformer whereby current flow is inhibited until both discharge devices are secured in the fixtures and dangerous socket-to-ground voltages are prevented during discharge device installation.

Abstract: An irradiation apparatus having a housing, a reflector and a source of ultraviolet radiation. The irradiation apparatus has a timing mechanism detachably located within the housing, the timing mechanism being an integral portion of the circuit which supplies power from a power source to the ultraviolet radiation source. The timer is adapted to be removed from the housing and attached to the housing by means of a cord having a non-standard plug to allow the lamp to be operated by means of the timer from a remote position.

Abstract: A safe "phantom" lamp structure for replacing a fluorescent lamp in a two-lamp series circuit connected fluorescent fixture which permits the remaining lamp of the two-lamp fixture to operate. The structure includes, in different embodiments, one or more magnetically or thermally actuated switches which must be closed for completion of the phantom lamp circuit and the switches are closed only after connection of both ends of the phantom lamp to the appropriate fixture sockets.

Abstract: An illumination control system for gas discharge lamps which can be dimmed is provided in which a central inverter produces a sinusoidal output voltage at about 23 kHz. The amplitude of the inverter output is adjustable to dim the lamps. A transmission line consisting of spaced wires having respective thick insulation sheaths distributes the high frequency power to remotely located assemblies of ballasts and lamps. The ballasts consist of passive linear components. A high power factor rectifier network is disclosed for providing a d-c input to the inverter from the 50/60 Hz mains. The inverter circuit is provided with novel controls for gradual start-up and turn-off and is protected against load fault currents and internal fault currents. Automatic and manual resets are provided for internal fault current and load fault current, respectively. The basic inverter circuit consists of two alternately conducting controllably conductive power switching devices.

Abstract: The device disclosed herein has a construction such that when a vehicle in motion is brought to a stop by depression of a foot brake, a lock engaging means thereof functions to lock a brake operating rod with the foot brake kept in the depressed state. When the headlights of the moving vehicle are turned on, the actuation of the lock engaging means automatically causes the headlights to be turned off and small lamps (parking lights) to be turned on instead. When the lock engaging means is released in preparation for starting the vehicle, the brake operating rod is released and the headlights are turned on again and the parking lights are turned off.

Abstract: A circuit employing an oscillator having a feedback loop for supplying operating current at a frequency in the range 20-25 kilohertz to a pair of fluorescent lamps connected in series. The heater filament of the first lamp is made a series element in the feedback loop of the oscillator, so that removal of that lamp disables the oscillator. Switching means is provided to bypass the open socket terminals of the second lamp when it is removed from its sockets, permitting power to continue to be supplied to the first lamp.

Abstract: A string set, of the type used on Christmas trees, of series-connected incandescent lamps where two lamps nearest the string set plug are unshunted and are connected to the plug through a wire of a gauge larger than the wire connecting the remaining lamps in the set. The unshunted lamps and the larger wire serve as a fuse for the entire set.

Abstract: A device for replacing a fluorescent lamp in a two lamp serially connected fluorescent fixture either of the type which includes a rapid-start type transformer for every two rapid-start fluorescent lamps or an instant start fixture for every two instant start lamps. By placing the device in the fixture in place of one of the two lamps the remaining lamp is energizable to provide illumination, whereas without the device the remaining lamp is inactive.