Abstract: A loudspeaker cabinet in which an elongated enclosure has a driver mounted internally in one wall thereof in facing, open communication with the exterior of the enclosure and an outlet sound port positioned in spaced relation to the driver in another wall of the enclosure remote from the one wall. An audio transmission passage extends longitudinally at right angles to the axis of the driver and is defined by baffles extending in equally spaced parallel relation to one another to divide the passage into a plurality of communicating folded passage sections extending from open communication with the driver to terminate in the outlet sound port. The total length of the passage through its cross-sectional area is on the order of from 8:1 to 16:1 so that at low frequencies air pulses delivered by the driver will remain in phase throughout the length of the transmission passage.

Abstract: The saturation front in each dessicant bed of a twin tower fractionating apparatus is located by sensizing a temperature gradient associated with the advancing saturation front. A pair of temperature sensors operatively sense the temperature in front of and behind the saturation front to provide a saturation front signal. The saturation front signal operatively controls the cycling of the inlet fluid mixture between the two dessicant beds of the fractionating apparatus. By sensing the location of the saturation front before it breaks through the dessicant bed, cycling occurs before each bed becomes fully saturated, but the substantial capacity of the dessicant bed is utilized to prolong the lifetime of the dessicant and to more effectively utilize energy by eliminating excessive waste purge gas. A maximum extend time period is provided for cycling the inlet flow mixture when a saturation front signal is not supplied under low flow rate conditions.

Abstract: A power supply system for portable floodlighting equipment employing high-intensity electric discharge lamps comprises an alternating current generator having two independent armature windings, one for producing current at a standard voltage and the other for producing current at a voltage sufficiently high for starting a discharge lamp in series with a capacitor. The two windings are out of phase and interference with the operation of the lamps energized by the first winding and electric apparatus energized by the second is effectively eliminated. The use of the generator winding for starting and energizing the lamps eliminates the usual starting ballast and decreases the weight and cost of the portable floodlighting unit.