Abstract: An improved, more energy efficient reactor-type ballasting circuit for fluorescent lamps includes an inductive ballasting coil for directly applying an AC line voltage to the cathodes of a lamp without an intermediate autotransformer and also includes a glow type thermal switch in series with a positive temperature coefficient (PTC) resistor for electrical connection across the cathodes of the lamp to conduct pre-heating current to the lamp cathodes. The PTC resistor will effectively remove the glow switch from the ballast circuit if the switch fails to open after an appropriate time delay.

Abstract: An improved ballast circuit for fluorescent lamps includes an electronic bilateral triggering device and a capacitor connected in series combination across the secondary winding output terminals of a ballasting transformer and in shunt with the fluorescent lamps. The triggering device and the capacitor operate to produce high frequency oscillations superimposed on the high AC voltage applied across the lamp cathodes to improve the capacitive coupling between the lamps and their mounting fixture during starting. The triggering device becomes nonconductive to effectively remove itself and the capacitor from the starting circuit while the lamps are lit.

Abstract: An amalgam of mercury is placed at the anode end of a low-pressure mercury discharge lamp for D.C. operation to counteract mercury vapor depletion at the anode end of the lamp. The amalgam attracts mercury vapor to the anode end of the lamp when the lamp is turned off to maintain uniform mercury vapor distribution in the lamp.

Abstract: A direct-current power supply circuit for gas discharge lamps includes a rectifier-capacitor bridge having a pair of input terminals and a pair of output terminals. A series input inductor is connected to one of the input terminals of the rectifier-capacitor bridge, and a pair of feedback diodes is connected to the output terminals of the rectifier bridge to provide a feedback signal to the series input inductor to control ripple of d-c output from said bridge and power factor of the a-c input to said bridge.

Abstract: A low pressure gas discharge lamp ballast circuit is provided for three series-connected low energy gas discharge lamps, in which a first starting capacitor provides a starting voltage to one of the lamps, and a second starting capacitor provides a starting voltage to a second one of the lamps in sequence, so that the ballast losses can be minimized by reducing the ratio of the voltage applied across the three lamp system to the total lamp voltage, while still maintaining the light output and not having to use expensive lamp bases and lampholders.

Abstract: Two or more fluorescent lamps having a total length of about 96 inches and each having a diameter of one and a half inches and consuming less than 10 watts power per foot of length are connected in electrical series combination, one cathode of each lamp being connected to that of another lamp. An end of each remaining cathode of the combination is respectively connected to one of a pair of input electrical power terminals for a 50 or 60 hertz a-c line voltage in the range of 200 to 300 volts, one of the latter connections being via a ballast inductor. A starter switch is connected across the other ends of the remaining cathodes, and a secondary winding on the ballast inductor is connected across the interconnected cathodes. The lamp designs are specified such that they will start and operate in the circuit from the a-c line voltage.

Abstract: A multiple fluorescent lamp ballast circuit of the rapid start type in which heating current is supplied to the lamp cathodes. A time delay switch is connected in series with a starting capacitor across one or more of the lamps, to delay lamp starting until the cathodes are sufficiently heated.

Abstract: A circuit for starting and operating fluorescent lamps from an a-c power source, comprising reactive ballast means connected to ballast the lamps and having a non-linear characteristic for producing harmonics of the power source frequency, and a capacitor and a cathode heating transformer connected in series and connected to receive power from said ballast means and resonant in a frequency range including two or more of said harmonics. A switch may be connected in series with the capacitor and cathode heating transformer for opening the cathode heating circuit when the lamps are operating, to conserve electrical energy.

Abstract: A U-shaped discharge lamp, such as a fluorescent lamp, is provided with a starting strip in the form of a pair of conductors respectively extending partially along the legs of the lamp, and an electrical connection is made between the conductors at one end thereof. This electrical connection can consist of or be combined with a support strap. An additional starting strip component can be provided on the U-bend portion of the lamp.

Abstract: An integrally connected fluorescent lamp and ballast unit having an elongated ballast of wire wound around and along an elongated magnetizable core and extending alongside an elongated lamp bulb. The elongated lamp and ballast can be straight, or can be curved. The ballast provides a combined resistive and inductive ballasting impedance for the lamp.

Abstract: Electrical lamp ballast system for starting and operating fluorescent lamps with improved efficiency. System includes high leakage reactance autotransformer having primary and secondary windings, and a ballast capacitor connected in series with the secondary winding and two serially connected fluorescent lamps of low starting and operating voltage, the secondary circuit being connected to a tap on the primary winding for reducing the ratio of the ballast power input to the lamp light output. The system provides for reduced lamp current crest factor, thereby improving life and operating characteristics of the lamps.

Abstract: Electrical lamp ballast system for starting and operating fluorescent lamps with improved efficiency. System includes high leakage reactance autotransformer having primary and secondary windings, and a ballast capacitor connected in series with the secondary winding and two serially connected fluorescent lamps of low starting and operating voltage, the secondary circuit being connected to a tap on the primary winding for reducing the ratio of the ballast power input to the lamp light output. The system provides for reduced lamp current crest factor, thereby improving life and operating characteristics of the lamps.