Abstract: A user-responsive system has a controller and a plurality of remotes. Each remote typically has a corresponding sensor and/or actuator. Applications for this system include, but are not limited to heating, ventilating, and air conditioning systems, lighting systems, security systems, energy management systems, home automation systems, and home entertainment systems.

Abstract: A discharge vessel for an electrodeless lamp having a pair of substantially parallel front and back walls. In one implementation, the front wall of the discharge vessel has a collimating structure, e.g a fresnel lens, for directing the light in a preferential direction such as in a flood light. In another implementation, the flat discharge vessel is quadrilateral and together with one or more quadrilateral excitation coils can be used as a backlight for a flat panel display. In yet another implementation, a cup-shaped discharge vessel with a collimating structure on the front wall is used in an electrodeless lamp for a task lighting such as a spot light.

Abstract: In some embodiments, a light bulb for an electrodeless discharge lamp has a protuberance such that the cold spot of the bulb is located in the protuberance. The protuberance is spaced from the induction coil of the lamp so as to be easily accessible. Hence the cold spot temperature is easy to measure and control. In some embodiments, heat sinks are provided to cool the light bulb. An active control element including a Peltier element is provided to control the cold spot temperature.

Abstract: A meter reader for reading a meter by reading a shadow made by a meter pointer on the face of the meter. The meter reader includes a light source for shining a light toward the meter, a pulse control circuit for pulsing the light source, two light sensors for receiving reflections of the pulsed light from two sections of the face, a detection circuit for detecting the intensity of the reflections received by each of the sensors, a microprocessor system for calculating an intensity relationship between the intensities received by each of the sensors, a counter for incrementing a meter readout count when the intensity relationship varies indicating that the shadow has passed over both sections of the meter face, and a transmitter for transmitting the meter readout count in a meter readout signal.

Abstract: An amalgam system for optimizing the mercury vapor pressure of an electrodeless discharge fluorescent lamp is disclosed. A coil network induces an electric discharge in a gas mixture contained in a sealed lamp vessel. An amalgam is supported in the discharge and thermally isolated from the lamp vessel by a thin glass strand. The discharge transfers power directly to the amalgam, thus quickly heating the amalgam. Rapid heating of the amalgam provides a rapid increase in mercury vapor pressure in the lamp so that the light output rises quickly when the lamp is energized. An impedance matching and filter network is constructed such that, in combination with the coil/plasma load, it provides a desired steady-state impedance and a desired start-up impedance.

Abstract: A discharge vessel for an electrodeless lamp having a pair of substantially parallel front and back walls. In one implementation, the front wall of the discharge vessel has a collimating structure, e.g a fresnel lens, for directing the light in a preferential direction such as in a flood light. In another implementation, the flat discharge vessel is quadrilateral and together with one or more quadrilateral excitation coils can be used as a backlight for a flat panel display. In yet another implementation, a cup-shaped discharge vessel with a collimating structure on the front wall is used in an electrodeless lamp for a task lighting such as a spot light.

Abstract: A wireless communication system with one or more remote transceivers for transmitting a wireless data signal at an actual frequency that is different than the expected frequency and a base transceiver that can automatically adjust to receive the actual frequency. Each remote transceiver is adapted to initiate a wireless data signal at a selected time that is unique to that remote transceiver. The expected frequency is sequentially pre-determined in a pseudo-random sequence with each remote transceiver having a unique sequence. The base transceiver can respond to the remote transceiver at the actual frequency. Both the remote transceiver and the base transceiver can convert the wireless signals in a single step to baseband.

Abstract: An amalgam system for optimizing the mercury vapor pressure of an electrodeless discharge fluorescent lamp is disclosed. A coil network induces an electric discharge in a gas mixture contained in a sealed lamp vessel. An amalgam is supported in the discharge and thermally isolated from the lamp vessel by a thin glass strand. The discharge transfers power directly to the amalgam, thus quickly heating the amalgam. Rapid heating of the amalgam provides a rapid increase in mercury vapor pressure in the lamp so that the light output rises quickly when the lamp is energized. An impedance matching and filter network is constructed such that, in combination with the coil/plasma load, it provides a desired steady-state impedance and a desired start-up impedance.

Abstract: In some embodiments, a light bulb for an electrodeless discharge lamp has a protuberance such that the cold spot of the bulb is located in the protuberance. The protuberance is spaced from the induction coil of the lamp so as to be easily accessible. Hence the cold spot temperature is easy to measure and control. In some embodiments, heat sinks are provided to cool the light bulb. An active control element including a Peltier element is provided to control the cold spot temperature.

Abstract: An arrangement for adjusting the intensity of an electrodeless discharge lamp is described. In one embodiment the high-frequency signal delivered to the induction coil is interrupted during a predetermined portion of a full duty cycle. This function is provided by a dimmer control unit which may be in an analog or digital form and may respond to a control signal provided by a potentiometer, a three-way lighting fixture or an addressable, remote controlled interface with data transmitted over the power lines or over a radio or infrared communication channel. In another embodiment the dimmer control unit alters the amplitude of the high-frequency signal supplied to the lamp's induction coil.

Abstract: An impedance matching and filter network is disclosed. The network performs two preselected impedance transformations and provides a filtering function to attenuate harmonics of an electrical signal delivered at an input of the network. The network may advantageously be structured in the form of balanced dual filters which are referenced to a virtual ground between them, the virtual ground being connected to a shield which surrounds the electric components. The network is particularly suitable for use with electrodeless discharge lamps to provide an impedance matching function for the induction coil and to limit RFI.

Abstract: A push-pull Class E amplifier is used to provide an efficient transfer of power to the induction coil in an electrodeless discharge lamp and to reduce the amount of radio frequency interference emitted by the lamp into the surrounding environment. A bifilar or other type of multifilar induction coil, preferably center-tapped, is used to further reduce the radio frequency interference problem.

Abstract: A cost-efficient electrically conductive screen and shield for substantially shielding radio frequency electromagnetic radiation emitted beyond the discharge vessel and the electronic circuitry of an electrodeless discharge lamp is disclosed. The conductive screen and/or shield is disposed outside the space occupied by the gaseous mixture and is grounded to the power supply. This shielding reduces the emission of electromagnetic radiation and, in particular, enables the discharge lamp to comply with FCC standards imposed with respect to the maximum admissible level of interference with wireless communication equipment such as radios and televisions.

Abstract: A push-pull Class E amplifier is used to provide an efficient transfer of power to the induction coil in an electrodeless discharge lamp and to minimize the amount of radio frequency interference emitted by the lamp into the surrounding environment.

Abstract: An electrodeless discharge lamp includes a discharge vessel containing an ionizable vapor, a generator for providing a high frequency signal, and an induction coil adjacent the discharge vessel and connected to the generator. The induction coil is shaped in the form of a planar spiral. The spiral coil is formed of wire or made of metal etched in a spiral pattern onto a substrate. The electrodeless discharge lamp having a spiral induction coil shows low lumen depreciation, a high linear relationship between light output and power input and produces low radio frequency interference.

Abstract: A high-efficiency Class D amplifier is described. In one embodiment, the amplifier contains two transistors which are turned on and off in sequence, the output being taken from the common node between the transistors. The efficiency of the amplifier is substantially increased by insuring that voltage across each of the transistors is substantially zero when it turns on. This advantage is achieved by connecting an inductance to the common node, so that the electrical energy stored in any stray capacitance is transferred to the inductance before any transistor is turned on.

Abstract: A price display system for a store includes spread spectrum radio broadcasting of UPC and price data from a transmitter in the store to a large number of receivers. Each receiver is connected to one or more LCD displays attached to the store shelves, and each receiver provides the relevant information to each of the connected displays. The displays and receivers are battery powered.