Abstract: A ballast circuit for a plurality of serially connected, high pressure gas discharge lamps comprises an electromagnetic ballast arrangement receptive of an input power signal, providing an output ballast voltage for driving the plurality of lamps, and providing an open circuit ballast voltage when the lamps are disconnected from the arrangement. A first ignitor circuit is connected between the ballast arrangement and the first lamp, and produces at least one ignitor pulse of high voltage and high frequency compared to the open circuit ballast voltage, to initiate starting of the first lamp. A second ignitor circuit is connected between the first lamp and a second lamp so as to be supplied with current through the first lamp. The second circuit produces at least one ignitor pulse of high voltage and high frequency compared to the open circuit ballast voltage after the first lamp begins to start and drops substantially in impedance, to initiate starting of the second lamp.

Abstract: A portable communication and audio system includes a radio telephone for receiving a first audio signal and transmitting a corresponding first radio signal through a transmitter to another location, and for receiving a second radio signal through a receiver and converting it to a second audio signal. An audio device provides a third audio signal. A microphone receives the first audio signal. A headset with first and second speakers is provided for selectively listening to the second or the third audio signal. A user-operated switch selectively disables the first speaker in a first state or the microphone in a second state. A state-indicating apparatus produces a signal indicating the state of the user-operated switch.

Abstract: A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating the gas discharge lamp and including a resonant inductance and a resonant capacitance. 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 which are connected together at a common node through which the a.c. load current flows. A voltage-breakover (VBO) device is effectively connected between the common node and a second node. A network is provided for setting the voltage of the second node with respect to the common node at less than the breakover voltage of the VBO device when the lamp is operating at steady state. 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 upon the firing of the VBO device.

Abstract: A power supply circuit for powering a load circuit comprises a load circuit and includes a converter circuit for inducing current in the load circuit. The converter circuit comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor, and connected together at a common node through which the load current flows. The first and second converter switches each comprise respective interconnected control nodes and references connected together at the common node. The voltage between a control node and associated reference node determines the conduction state of the associated switch. A first node is coupled to the bus conductor, and a second node is coupled to the reference conductor. A bridge network is connected between the first and second nodes and has first and second input nodes on which respective first and second input signals are applied.

Abstract: A circuit with a small package for MOSFETs comprises a load circuit in which an a.c. current flows. Further included are a p-channel enhancement-mode MOSFET and an n-channel enhancement-mode MOSFET, the sources of which are connected together at a common node through which the a.c. current flows. The MOSFETs respectively provide positive-going and negative-going contributions to the a.c. current, with approximately equal r.m.s. values. A package is provided in which the MOSFETs are arranged adjacent to each other, in the same plane. A main surface of the package has an area of no more than about 40.5 square millimeters. The channel area of the p-channel MOSFET is from about 1.4 to about 2.0 times the channel area of the n-channel MOSFET.

Abstract: A compact coupling arrangement between a light source and a plurality of light distribution harnesses includes a plurality of reflector members arranged around the light source with respective focal points of the reflector members positioned substantially coincident with the light source, so as to receive light from the source and reflect the light away from the source. Further included is a plurality of light coupling members, each having an inlet and an outlet surface for receiving light originating from the light source and transmitting light, respectively. A plurality of light distribution harnesses is provided for respectively receiving light from the light coupling members. The light coupling members each comprise a lens having a negative curvature in at least one direction generally transverse to a main light transmission axis therethrough, for receiving light at a first angular distribution and transmitting light at a reduced angular distribution.

Abstract: 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.

Abstract: A gas discharge lamp ballast comprises a load circuit including circuitry for connection to a gas discharge lamp. A circuit supplies d.c. power from an a.c. voltage. A d.c.-to-a.c. converter circuit is coupled to the load circuit for inducing a.c. current therein. The converter circuit comprises first and second converter switches serially connected in the foregoing order between a bus node at a d.c. voltage and a reference node, and being connected together at a common node through which the a.c. load current flows. The first and second converter switches each have a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the first and second converter switches are interconnected. The respective reference nodes of the first and second converter switches are connected together at the common node.

Abstract: A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating the gas discharge lamp and including a resonant inductance and a resonant capacitance. 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 converter switches serially connected in the foregoing order 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 converter switches comprise respective interconnected control nodes respective reference nodes interconnected together at a common node. The voltage between each control node and associated reference node determining the conduction state of the associated switch. A voltage-limited energy source is connected between first and second nodes.

Abstract: A high intensity discharge lamp comprises an elongated, main arc tube containing a gas fill. First and second in-leads are connected to first and second electrodes within the arc tube, with an arc gap being defined in the arc tube between the electrodes. The fist and second in-leads are adapted to be connected to first and second power leads of a ballast circuit. A starting aid is included for the main arc tube and comprises a path generally parallel to the main arc tube along the arc gap and which is conductive during starting of the main arc tube; an electron barrier disposed between the path and the main arc tube for preventing a substantial amount of photoelectrons from collecting on an outer surface of the main arc tube; and first and second ends of the path being coupled to the first and second in-leads by first and second electrical couplings.

Abstract: A metal halide gas discharge lamp comprises an arc tube containing a vaporizable metal halide and first and second spaced electrodes. An arrangement for heating the arc tube assists in creating an arc discharge between the first and second electrodes. It comprises a heat source positioned to heat the arc tube, and an electron barrier disposed between the heat source and the arc tube for minimizing accumulation of photoelectrons on an outer surface of the arc tube so as to substantially avoid sodium migration out of the arc tube. A switch deactivates the heat source after the arc tube is heated a desired amount.

Abstract: A universal electronic ballast self-accommodates to appropriately supply power to each one of a family of different fluorescent lamps, one at a time. The ballast comprises a circuit for supplying a.c. current to a lamp in such manner that current in the lamp varies as a function of an error voltage. A summing circuit is provided together with an error amplifier for amplifying the output of the summing circuit to produce the error voltage. A circuit produces a reference voltage that is supplied to the summing circuit. A current feedback circuit feeds back to the summing circuit a first signal that varies as a function of lamp current. A voltage feedback circuit feeds back to the summing circuit at least a second signal that varies as a function of lamp voltage in such manner as to realize a ballast current-voltage characteristic that intersects respective lamp current-voltage characteristics at desired operating power for each of the family of lamps.

Abstract: A gas discharge ballast circuit comprises a resonant load circuit including a resonant inductance, a resonant capacitance, and circuitry for connection to at least one gas discharge lamp. A d.c.-to-a.c. converter circuit is coupled to the load circuit for inducing an a.c. current in the circuit. It comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor, and connected together at a common node through which the a.c. load current flows. The first and second converter switches each comprise a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the first and second converter switches are interconnected. The respective reference nodes of the first and second converter switches are connected together at the common node.

Abstract: A ballast for an electrodeless gas discharge lamp comprises a load circuit including an r.f. inductor for generating an r.f. field for powering the electrodeless lamp and a serially connected resonant capacitance. The inductance of the r.f. inductor has a substantial effect in determining a frequency of resonance the load circuit. A d.c.-to-a.c. converter circuit is coupled to the load circuit for inducing a.c. current therein. It comprises first and second converter switches serially connected in the foregoing order between a bus node at a d.c. voltage and a reference node, and being connected together at a common node through which the a.c. load current flows. The first and second converter switches each has a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the first and second converter switches are interconnected.

Abstract: An electrodeless gas discharge lamp includes a vitreous envelope containing a discharge medium. An excitation coil is positioned in relation to the vitreous envelope so as to excite the discharge medium therein. The excitation coil is adapted to be driven by an RF oscillator. The excitation coil has first and second ends and is effective for exciting the discharge medium to emit light with electromagnetic fields that are generated by the excitation coil. The excitation coil includes a first wire wound generally helically from the first end to the second end in a first helical direction to form first winding turns, and further includes a second wire wound generally helically from the first end to the second end in second helical direction opposite to that of the first helical direction to form second winding turns. Preferably, a generally cylindrical former is provided for holding the first and second wires between the first and second ends of the coil.

Abstract: Disclosed is a shoe making system and a method of manufacturing a shoe, in which the work of fastening an inner sole to a wooden mold can be done easily and speedily. In the method, metal plates 23 and 24 having a magnetic absorption property are stuck to an inner sole 21 to form a magnetic absorption portion. On the other hand, magnets 33 and 34 are buried at positions corresponding to the metal plates 23 and 24 in a bottom portion of a wooden mold 31. The metal plates 23 and 24 are attached to the magnets 33 and 34 buried in the wooden mold 31, so that the inner sole 21 is fastened to the wooden mold 31. After the inner sole 21 is fastened to the wooden mold 31, the wooden mold 31 is covered with a shoe upper, and the shoe upper and the inner sole are joined by joins.

Abstract: A liner for a cat box having sides extending upwardly from a bottom to a vertical height. The liner comprises a bag for placement in the cat box. The bag comprises a bottom portion for lining the cat box, and a contiguous top portion. A fluid-impermeable layer is placed within the box, located within the bottom portion of the bag and bonded to the bag. A sorbent layer is placed above the fluid-impermeable layer. A claw-resistant layer is placed above the sorbent layer and affixed to the fluid-impermeable layer so as to stiffen the affixed layers, whereby they tend to stay in place in the cat box. The top portion of the bag drapes over the sides of the box for a drape length and provides ballast for helping the liner to stay in place.

Abstract: Disclosed is a ballast circuit for a gas discharge lamp comprising a resonant load circuit incorporating the gas discharge lamp, a resonant inductance, and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the load circuit, and comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor. The switches are connected together at a common node through which the a.c. load current flows. The switches each have a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the switches are interconnected, and the respective reference nodes of the switches are connected together at the common node.

Abstract: A network of identical atmospheric hazard detectors communicates a locally sensed hazard condition directly to multiple neighboring detectors using RF command communication, without the use of wires and without a central control location. Each detector includes a sensor of an atmospheric hazard, a detection circuit for measuring the sensor output and creating a local hazard signal, an alarm indicator, an RF transmitter for sending a neighboring hazard signal to the network, and an RF receiver for receiving a neighboring hazard signal from the network. The local alarm and neighboring alarm control signals produce discernibly different alarm indications from the detector's alarm device, facilitating an attempt to locate the origin of a hazard. In the preferred embodiment, every detector functions as a receive/transmit relay station, enabling the network to be extended in spatial expanse without limit and without increasing the power output of the RF transmitter.