Abstract: Herein described is a driver circuit of a fluorescent lamp having a first and a second electrode and igniting when the voltage between the first and second Electrode exceeds a given threshold voltage. The driver circuit comprises an inductance coupled to a supply voltage and to a terminal of the first electrode a first condenser coupled to the other terminal of the first electrode and to a terminal of the second electrode, a control device comprising a first and a second system of switches capable of guaranteeing oscillations of a voltage signal on the inductance and on the first condenser up to the ignition of the lamp. The driver circuit comprises a device associated to the control device and capable of acting on the first system of switches so as to regulate the frequency of the oscillations from a frequency greater than the resonance frequency of the inductance and of the first condenser to the same resonance frequency so as to guarantee a preheating of the first and second electrodes.

Abstract: An electromagnetic ballast for sequentially starting and simultaneously operating first and second gaseous discharge lamps includes a transformer having a magnetic core, a primary winding for connection to an AC voltage source and first and second secondary windings, all wound around the core. The first and second secondary windings are wound in opposite directions to produce voltages in opposition to each other. The ballast includes first and second series circuits, each including one of the lamps. The magnetic core has an elongated slot formed under the second secondary winding. The slot width relative to the core width, and to the slot length, are dimensioned to provide improved operating performance.

Abstract: A monochromic, multi-color and full-color cold cathode fluorescent display (CFD), comprises of: some shaped white or multi-color or red, green, blue three primary color cold cathode fluorescent lamps (CCFL), reflector, base plate, temperature control means, luminance and contrast enhancement face plate, shades and its driving electronics. CFD is a large screen display device which has high luminance, high efficiency, long lifetime, high contrast and excellent color. CFD can be used for applications both of outdoor and indoor even at direct sunlight, to display character, graphic and video image.

Abstract: The invention relates to a high-pressure discharge lamp having a base at one end and whose return conductor (13) is protected with the aid of a bidirectional trigger (D) against high induced voltages of the radio interference suppression reactor (L1) connected to the return conductor (13).

Abstract: A lamp start, hot-restart and operating circuit for a high wattage, high intensity discharge lamp includes cascaded resonant circuits with capacitors and series-connected inductors connected to an AC source. A pulse circuit including two pulse transformers supplies streamer-forming current, the secondary windings of the pulse transformers being connected in series with the lamp. When the lamp commences normal operation, the operating current energizes a relay to remove the capacitors and pulse circuit from the operating circuit, allowing the inductor to function as the lamp ballast.

Abstract: A circuit for starting, operating and instant hot restarting of high intensity gaseous discharge lamps utilizes a conventional ballast, an ignition transformer and a pulse transformer. The ignition transformer is connected across the ballast output and is in circuit with a storage capacitor and a spark gap device which, in combination, provide high frequency, high voltage pulses to a pulse transformer which is in circuit with the high intensity gasesous discharge lamp. There are means to limit the duration during which the high frequency, high voltage pulses are applied to ignite the lamp and there is a current sensitive timing circuit breaker to protect the lamp and ignition circuit.

Abstract: A lighting apparatus for an electric discharge lamp includes a lighting ballast capacitor connected in series to an electric dicharge lamp for stabilizing a lighting current to the lamp; a preheating ballast capacitor connected in parallel to the lamp for supplying a preheating electric power to the lamp; electric power supply including an output transformer for supplying an electric power to the lighting ballast capacitor; a control electric power supply circuit for obtaining a control electric power through the lighting ballast capacitor and discharge lamp or the preheating ballast capacitor without adding a stepdown transformer or a resistive element for voltage drop; and an oscillator which receives the control electric power from the control power supply circuit and controls the electric power supply. With this lighting apparatus, the electric power loss is made small and the miniaturization of the apparatus can be realized.

Abstract: A heat flow detector for protecting against overheating of a lamp fixture energized from a voltage source, even when a dimmer is used for operating the lamp fixture. The detector includes a temperature sensitive switch electrically coupled to the lamp fixture. The switch disconnects the lamp fixture from the voltage source in response to a predetermined temperature. A biasing heater is thermally coupled to the temperature sensitive switch for raising the temperature of the switch sufficiently to operate the switch upon overheating of the lamp. A regulating circuit maintains the required voltage across the heater even upon reduction of the voltage from the source through use of the dimmer. The heat flow detector is placed in the vicinity of the lamp fixture so as to be subject to the same heat flow environmental conditions as the lamp fixture whereby as the lamp fixture gets overheated, the resistor heated up will be sufficient to operate the switch.

Abstract: A lighting apparatus which provides high voltage pulses for starting a high pressure sodium lamp. The apparatus includes two capacitors, two blocking diodes, a voltage sensitive symmetrical switch, and multiple resistances across which pulses are distributed. The aforementioned elements are electrically connected together and with a tapped ballast reactor so that one of the capacitors charges through an impedance in the negative half-cycle, and thereafter, when line voltage goes positive, the other capacitor charges through an impedance equal to the sum of the multiple resistances. When the voltage of the capacitors reaches a predetermined voltage exceeding the breakdown voltage of the voltage sensitive symmetrical switch, the capacitors discharge. This discharge, because of an autotransformer relationship within the reactor, produces a high voltage pulse of predetermined height and width once per each cycle of the source voltage.

Abstract: The above and other objects, advantages and capabilities are achieved in one aspect of this invention by a drive scheme for a plurality, that is, for N, where N-2, flourescent lamps. The drive circuit comprises (N+1) pairs of output terminals, each comprising associated first and second individual terminals. An output transformer is coupled at one end to the (0,1).sup.1 terminal and at another end to the (0,1).sup.N+1 terminal. N impedance elements, typically capacitors, are coupled across associated pairs of lamp filaments in a fashion whereby each impedance element is coupled at one end to the second terminal of one pair and at another end to the second terminal of the succeeding pair. To wit: The first impedance element is coupled between the second terminal of the first pair, and the N.sup.th element is coupled between the second terminal of the N.sup.th pair and the second terminal of the (N+1).sup.th pair.

Abstract: A frequency stabilized automatic gain controlled ballast system (10) which is coupled to a power source (12) in order to operate at least one of a pair of gas discharge tubes (40 and 40'). Each of the gas discharge tubes (40, 40') include respective filaments (42, 44 and 42', 44'). A frequency control circuit (11) is coupled to the power source (12) and includes a frequency control transformer (43) and a frequency control capacitor (50) for establishing a constant oscillation signal at a predetermined frequency. A switching network (13) is connected to the frequency control circuit (11) for establishing a pulsating current responsive to the constant oscillation signal of predetermined frequency. Induction circuitry (15) is coupled to the switching network (13) and the frequency control circuit (11) and includes an inverter transformer (78) as well as coupling capacitors (86 and 88) for generating a voltage across the gas discharge tubes (40 and 40').

Abstract: A device is disclosed for converting fluorescent lighting fixtures, having a conventional series-type ballast with at least two lamps, to effect illumination of only one of the two lamps at a time, but automatically effecting illumination of the other lamp upon that one becoming disabled. The device includes an induction coil to increase the starting boost available to one of the two lamps and also has a varistor. The varistor may be connected across a secondary coil of the ballast which is then arranged to idle. With fixtures having two pairs of instant-start lamps, the varistor is instead connected to an electrode of one lamp of each pair. The device preferably has a series circuit comprising the varistor, the inductive coil, a capacitor and a resistor. Preferably four electrical connections, two across the varistor and two across the inductive coil, are provided to connect the device into the circuitry of the ballast and lamps.

Abstract: An energy-saving instant-start series-sequence fluorescent lamp system includes power-reducing capacitor means connected in series circuit arrangement with one or both lamps in a two-lamp system. A protective device is connected in circuit with a first lamp of the system so that in the event the second lamp fails to operate and causes a high current to flow through the first lamp, the protective device reacts to prevent the system from being damaged. A lamp incorporating the power-reducing capacitor and protective device is also disclosed.

Abstract: A starting circuit for a high intensity discharge lamp. To provide the high voltage necessary for starting the lamp, the circuit uses a tapped transformer feeding a resistance-capacitance charging network coupled across the lamp. A voltage sensitive symmetrical switch is located in the network between the transformer tap and the RC junction to trigger the circuit when the open circuit voltage of the ballast is at its peak. A diode within the network is in series with resistance to allow current to flow during one half cycle of the cycle allowing the use of an inexpensive resistor in the RC network. A bleed resistor is placed in shunt of the capacitor to stabilize the triggering time of the network.

Abstract: A lighting unit is described utilizing an energy efficient metal vapor arc lamp as the main source of light supplemented by a standby filamentary light source producing light when the arc lamp is being started. The lighting unit is designed as a more efficient replacement for the incandescent lamp. The lighting unit includes means for conversion of 60 hertz ac to dc, and a dc energized operating network, including a ferrite transformer and an intermittently operated switching transistor serially connected with a load consisting of the filament or the arc lamp, or both, to which regulated output power is provided. The operating network produces an output with minimum dissipation adapted to each operating state of the arc lamp, including the provision of a high ignition potential, adequate power for the lamp during the glow to arc transition, warm-up and ballasting. In addition, while the arc lamp is being started, the operating network provides power for lighting the standby filament.

Abstract: A lamp operating circuit comprising a DC power source, an inverter including step-up transformer inductance windings and a controlled transistor switch connected across the output of the DC source, and a high frequency oscillator coupled to the transistor switch for operating the same at predetermined intervals. A low wattage HID lamp is connected across the inverter through a ballast capacitor series connected to one terminal of the lamp and a ballast inductance coupled in series with the other lamp terminal. The ballast inductance and ballast capacitor are selected to resonate sinusoidally at a frequency having a half period coinciding with the on-time of the transistor.

Abstract: Electrical ballast circuit of improved power factor for operating gaseous discharge lamps. Two discharge lamps are respectively connected to two inductively coupled induction coils for obtaining high power factor without the use of capacitors.

Abstract: An inverter circuit suitable for use as a fluorescent lamp inverter ballast is disclosed. The inverter has the capability of starting the fluorescent lamp through regenerative feed-back techniques made possible by the amplification characteristic of the inverter switching transistor. Good efficiency at high frequency is provided by minimizing the transistor switching losses through use of resonant storage techniques and an unique feed-back system. Further, the normal energy lost in the feed-back circuit is eliminated by combining the resonant load means and the feed-back means into a single structure.

Abstract: Circuits are disclosed for starting and operating a high pressure sodium vapor lamp in combination with another gaseous discharge lamp of low voltage breakdown characteristics. The sodium vapor lamp is connected in series with a ballast induction coil, while the low voltage breakdown lamp, a portion of the ballast coil at its input side, and a capacitor are connected in a series discharge loop to produce high frequency, high voltage pulses for starting the sodium vapor lamp, and providing for operation of both lamps. A ballast capacitor is connected in series with the low voltage lamp to provide a lead ballast circuit therefor.