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: 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.

Abstract: A tape measure 20 includes a display window 24 for presenting a digital presentation of the measurement being made. The tape measure 20 includes an encoder 74 which provides for a combined absolute scale 95 and relative scale 105 for determining the measurement. Perforations 62 in the tape 26 are mated with pins 60 extending from a capstan 58 in order to cause the encoder 74 to send signals to a microprocessor 76. The microprocessor 76 processes the signal and displays the measurement.

Abstract: A security and control system for use in a home or building which utilizes a coded audio link between the entry detectors/transmitters and the relay modules, and a digital pulse coded power line communication ("PLC") link between the relay modules and the system controller as well as between the system controller and the various remotely located slave units which control the energization of lamps, appliances, and alarms. The relay modules and controller include constant false alarm rate ("CFAR") receivers for isolating the coded audio signal from background noise and unique exclusion circuitry for decoding the isolated signal. The PLC messages are generated by impressing a pulse code modulated high frequency carrier signal onto the AC line at selected points in the AC waveform. The location of each carrier frequency pulse relative to the 60 Hz AC line cycle determines the digital value of the pulse.

Abstract: A second photoelectric element or cell (P2) is mounted in series with a first photoelectric element or cell (P1) of the prior art and in parallel with a portion of a voltage divider of which said first element is a part to shunt out a portion of the divider in response to light from a light load turned on by the operation of said first element incident to an increase in impedance thereof due to ambient darkness. Addition of the second photoelectric cell results in hysteresis of the turn-on/turn-off operating points of the first cell to prevent flicker to the light which is present at or near dusk in lights controlled by the prior art circuits. Mechanically, one cell (P1) is mounted on the side of a collar (21) surrounding the neck of a light bulb (13) outside direct light rays from the filament (23) while cell (P2) is mounted on the collar top in the direct path of light rays from the filament.

Abstract: A sensor timer is provided for automatically turning on and off a lamp or alternatively for allowing the lamp to be manually turned on and off using the switch normally associated with the lamp. The sensor timer automatically senses the arrival of nighttime despite seasonal variations in the actual time of nightfall and automatically turns on the lamp a first selected time period after nightfall. The lamp is then automatically turned off a second selected time period after the lamp has been turned on or alternatively is turned on and off randomly during the second selected time period. The sensor timer can also dim the lamp. The sensor timer converts from automatic mode to manual mode in response to the turning on of the lamp through its manual switch thereby to allow the lamp to be controlled directly by the manually operated lamp switch. To convert the sensor timer from manual mode to automatic mode the lamp switch is turned on, off and on in rapid succession.

Abstract: A programmable wall switch for controlling the time for turning on and for turning off an incandescent light includes a rectifying circuit for producing from the AC power line a selected DC voltage. The switch includes a microprocessor powered by this DC voltage for turning on a light at any one of several selected times and for turning off the light at one of an additional corresponding several selected times. A time display is provided for displaying the time as well as for allowing a user to review the programmed status of the switch at any one of several selected times. A signal is generated at each zero crossing of the AC power line which is supplied to the microprocessor. The microprocessor produces output signals which turn on, turn off or dim the light at selected times. The ability of the microprocessor to dim the light further enhances the appearance of human occupancy when the switch is used to simulate occupancy of a vacant building.

Abstract: A circuit for adjusting the frequency of operation of an electronic time keeping device, which device includes a source of clock pulses. The circuit of this invention is preferably located between the source of clock pulses and the time keeping device counting circuitry, so that the clock pulses can be periodically interrupted for a programmed amount of time. Accordingly, the variable adjustment capacitor, typically employed in prior art time keeping devices, can be eliminated.