Abstract: A heater having selective power rating includes a source of electric current, at least one heating unit and at least one electric conductor having an input and an output. Each conductor is permanently fixed at its input and its output so that the conductor is in electric communication with the source. Each conductor is in one of two states. In a conducting state, the conductor is electrically continuous between its input and its output. In a nonconducting state, the conductor is severed between its input and its output. A first conductor is disposed with respect to the source and a first heating unit so that the first heating unit operates at a power level that is dependent on the state of the first conductor. The source and the at least one heating unit are configured to produce one of a plurality of a desired power levels depending on the state of the first conductor.

Abstract: A gas surface range having a downdraft ventilation system with automatic shut off during ignition. A relay is activated by current flowing to the spark coil of the electrical igniter, and has contacts connected in series with the blower motor of the downdraft system. Thus, the downdraft system is disabled during attempted ignition, and is automatically enabled at the completion of ignition.

Abstract: Method and apparatus for determining moisture content of materials by irradiating a sample of unknown moisture content with a narrow frequency band of light at a first wavelength during a first time period and a narrow frequency band of light of a second wavelength during a second time period. The two wavelengths of light have different water absorptive characteristics, and therefore are reflected by varying degrees depending on the surface moisture on the material. The respective reflections are measured by a single common detector, and a value corresponding to the ambient light is subtracted from each measurement. A ratio of the resultant values is then correlated with data derived from precalibration measurements of samples of known moisture content.

Abstract: A laser soldering system wherein a plurality of laser beams are simultaneously directed to a plurality of spatially separate locations on a printed circuit board for simultaneously soldering. Each of the laser beams is formed by combining the outputs of a plurality of fiber cables, each of which is connected to an individual laser diode.