General Electric Company

Michael M Secen

Louis Robert Nerone

Sayed-Amr A El-Hamamsy

Mark E Duffy

David Joseph Kachmarik

Gerald E Duffy

Curtis E Scott

Raymond A Heindl

Edward John Thomas

Frederick Hetzel

Lawrence T Mazza

Michael M Minarczyk

Kurt W Haas

David A Gwinn

David J Marks

A lamp is disclosed that includes a light source that requires high voltage for starting. A reflector body includes an electrically conductive reflective surface that is oriented to receive light from the light source and direct the light in the desired direction. A preselected surface portion of the reflector body is devoid of the electrically conductive reflective surface. First and second lead assemblies associated with the light source, and that supply power thereto, pass through openings in the reflector body. The lead assemblies are spaced from the electrically conductive reflective surface portion by the preselected surface portion that is devoid of the reflective material to preclude arcing. Asymmetrical lead wire assemblies may also be advantageously used to increase the electrical standoff.

PAR lamp with short arc HID bulb and cut-out in aluminum to prevent arcing

A ballast circuit for a gas discharge lamp comprises a resonant load circuit including the lamp. A d.c.-to-a.c. converter circuit induces an a.c. current in the resonant load circuit. The converter circuit comprises first and second switches serially connected between a bus conductor at a d.c. voltage and a reference conductor, and being connected together at a common node through which the a.c. load current flows. The first and second switches each comprise a reference node and a control node, the voltage between such nodes determining the conduction state of the associated switch. The respective reference nodes of the first and second switches are interconnected at the common node. The respective control nodes of the first and second switches are interconnected. An inductance is connected between the control nodes and the common node. A starting pulse-supplying capacitance is connected in series with the inductance, between the control nodes and the common node. A network is connected to the control nodes for supplying the starting pulse-supplying capacitance with charge so as to create a starting pulse during lamp starting, and for setting the voltage of the control nodes sufficiently close to that of the common node during steady state lamp operation so as to prevent the capacitance from supplying a starting pulse during the steady state lamp operation. A polarity-determining impedance is connected between the common node and one of the bus conductor and the reference conductor, to set the initial polarity of pulse to be generated by the starting pulse-supplying capacitor.

Lamp ballast with triggerless starting circuit

A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating a gas discharge lamp and including first and second resonant impedances whose values determine the operating frequency of the resonant load circuit. A d.c.-to-a.c. converter circuit is coupled to the resonant load circuit so as to induce an a.c. current in the resonant load circuit, and comprises first and second switches serially connected in the mentioned order between a bus conductor at a d.c. bus voltage and ground, and having a common switch node through which the a.c. current flows. A bridge capacitor has one end connected to ground. First and second feedback circuits regeneratively control the first and second switches, respectively, in response to a.c. current in the resonant load circuit. A starting circuit initiates operation of the first and second feedback circuits, and incorporates a voltage-divider network comprising first and second serially connected impedances with a common impedance node, and is coupled between the common switch node and ground. Such circuit includes a starting capacitor coupled between the common impedance node and ground, and a voltage-breakover switch coupled between a non-grounded end of the bridge capacitor and the starting capacitor. Also included in the starting circuit is a transformer winding serially coupled to the voltage-breakover switch so as to conduct a pulse of current when the voltage-breakover switch fires, the winding being coupled to the first and second feedback circuits so as to result in a starting pulse of current in the circuits when the voltage-breakover switch fires.

Diodeless start circiut for gas discharge lamp having a voltage divider

A ballast circuit for a gas discharge lamp, of the type having a pair of resistively heated cathodes that are resistively heated both during a cathode pre-heat period prior to lamp turn-on, and during steady state lamp operation, is disclosed. The ballast circuit includes circuitry for providing, on a bus conductor, a d.c. bus voltage with respect to a ground, and a converter, responsive to the d.c. bus voltage, for supplying bidirectional current to a resonant load circuit. The resonant load circuit includes the gas discharge lamp, a resonant capacitor coupled between the lamp cathodes such that its voltage varies with lamp voltage, and a resonant inductor serially coupled to the resonant capacitor and cooperating therewith to set a magnitude, and resonant frequency, of the bidirectional lamp current. Circuitry is provided for powering the resistively heated lamp cathodes, to thereby heat the cathodes. Further included is a circuit for maintaining the lamp voltage during a cathode pre-heat period below a predetermined level so as to prevent lamp turn-on during such period; such circuit includes circuitry for holding a first cathode of the lamp at a substantially constant voltage, and circuitry for clamping a second cathode of the lamp below the predetermined level. Such clamping circuitry includes a positive temperature coefficient (PTC) impedance device coupled to a second cathode of the lamp, and serially connected by a positively poled clamping diode to the bus conductor, and serially connected by a negatively poled clamping diode to the ground.

Ballast circuit for a gas discharge lamp having a cathode pre-heat

A simulated load circuit for measuring the impedance of the arc discharge of an electrodeless discharge lamp of the type having an arc tube and an excitation coil for exciting the arc discharge in an ionizable fill contained therein includes: a secondary coil spaced apart from the excitation coil by a distance which is varied in order to vary the coupling coefficient between the secondary coil and the excitation coil; a fixed load resistance coupled to the secondary coil; and a variable matching network coupled in series or parallel with the load resistance, the impedance of the matching network being varied in order to vary the ratio of reactance to resistance of the load circuit. The distance between the secondary coil and the excitation coil is varied, and the impedance of the matching network is varied, until the input impedance of the load circuit is substantially equivalent to the operating impedance of the lamp. The simulated load circuit is useful for designing and testing ballast circuits for electrodeless discharge lamps and for providing measurements of arc discharge power and excitation coil efficiency.

Simulated load circuit for simulating the arc impedance of an

A base for an electrodeless arc discharge lamp having an elongated tubular stem extending through an outer envelope pinch or press seal includes a pair of electrically non-conductive members secured in mating relation to define an upper cavity and a lower axial bore. The lamp is mounted in the base with its pinch seal secured in the cavity and its stem extending into the bore. With the base mounted in a fixture, RF energy is coupled into the lamp to excite a starting aid in the stem via a conductive bushing in the bore.

Base for electrodeless discharge lamp

An auto-starting lamp system comprises an electrodeless high intensity discharge lamp of the type including an arc tube that contains an ionizable fill, an excitation coil surrounding the arc tube for exciting an arc discharge in the ionizable fill at least during steady state lamp operation, and a starter circuit for facilitating arc discharge of the ionizable fill. The system further comprises a controllable r.f. power source for powering the lamp excitation coil, and an electrical network for matching the impedance of the excitation coil to the impedance of the r.f. power source. The impedance-matching network has the same impedance-matching relation during both lamp start-up and steady state lamp operation. A system controller causes the r.f. power source, during lamp start-up, to ramp up in power to a peak level preferably substantially in excess of a steady state lamp operating power level, and then to decrease from the peak level. Preferably, the system further comprises circuitry for re-powering the starter circuit after a predetermined period of time has elapsed that is sufficiently long as to prevent thermal damage to the lamp resulting from powering the starter circuit. The system preferably further comprises control circuitry for alternately turning on and turning off power to the starter circuit after the lamp ionizable fill recovers an ability to reach full arc discharge after being extinguished.

Auto-starting system for an electrodeless high intensity discharge lamp

Method for measuring the impedance of an electrodeless arc discharge lamp

A ballast circuit for operating a metal halide lamp by applying DC excitation during its start, glow and run modes is disclosed. The type and values of the circuit components of the ballast circuit are selected to provide automatic, sequential and desired transfer functions as the impedance value of the metal halide lamp transitions from its value occurring during the start, glow and run modes of operation. The ballast circuit has an input stage that is easily adapted to present a high power factor to the AC power source supplying the metal halide lamp. Further, the ballast circuit generates a signal for more easily starting the lamp and having a relatively high DC level upon which are developed pulse signals.

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Mentor, OH, United States of America

Michael M Secen