Abstract: A recessed canopy light having a main body positionable above an opening in a canopy sheet, a rim member in contact with the lower surface of the canopy sheet such that the sheet is sandwiched between the main body and the rim member, a lens frame below the rim member and hinged thereto, each hinge including a first member secured to the rim member and having an upwardly-open substantially semi-cylindrical female portion with an outer edge spaced below the canopy sheet by a first distance and a second member secured to the lens frame and having a truncated-cylindrical male portion engaged in the female portion, the male portion having a flat therealong such that the vertical dimension of the male portion varies between a full diameter much greater than the first distance and a truncated diameter which is at most slightly greater than the first distance, such that the male portion is non-removable from the female portion except when the lens frame is pivoted to a fully-open position beyond a vertical hanging p

Abstract: An institutional lamp includes several features to enhance lamp longevity and safety in an institutional setting. A diffuser/guard assembly fully surrounds the lamp bulbs to prevent casual disassembly or inadvertent contact with the bulbs. An auxiliary socket is provided that can be conveniently used to power other devices. A night light bulb is included and is also located within the diffuser/guard assembly. When so located, the lamp continues to provide a natural appearing illumination when the night light feature is used. An easy to use rocker switch is provided to enhance user operating convenience, and a durable, plastic lampshade avoids the types of damages frequently suffered by cloth shades. Preferably, the lamp is constructed of heavy, durable materials to improve durability. However, the lamp is styled and decorated to have the type of inviting appearance commonly associated with lamps intended for use in the home.

Abstract: A fixed image projection system that can project an image for a short or long period of time without damage to the film. The system is comprised of a light source having a halogen lamp and a cold coated reflector detachably mounted on a housing having film guides or rails for receiving a film frame. The housing includes a plurality of whisper fans that draw cool air into the housing and expel it from the opposite sides of the housing to maintain a relatively cool temperature at the film frame. Preferably, the fans have a dual speed control to allow a higher speed as an option. A lens barrel is detachably supported on the opposite side of the housing from the light source and includes movable lenses to focus the image. Images may be fed into the system on a film frame one at a time, or by motorized film canisters that allow forward or backward advancement to a selected image on a roll containing multiple images.

Abstract: A circuit arrangement according to the invention is intended to be used in a PIR motion-activated lighting fixture of the type that includes a triac for energizing the light from the AC power mains and a triac firing circuit for firing the triac in response to motion. To provide the accent lighting level and to control the magnitude of that level, the circuitry includes a window comparator, in which the thresholds are set to defining a dimming window, and a filter circuit responsive to the AC power line and providing an input signal to the window comparator. The filter circuit includes a circuit arrangement for shifting the phase of the input signal with respect to the AC power line signal and for contemporaneously scaling the amplitude of the input signal with respect to the AC power line signal such that the peak amplitude of the input signal diminishes as the phase shift of the input signal increases.

Abstract: An oscillator includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

Abstract: The present invention refers to a method for controlling a magnetron filament current. The control is provided by detecting the dynamic impedance or a noise level of the magnetron and by controlling the magnetron filament current based thereupon.