Abstract: A louvred handle assembly for equipment racks of the removable type in which louvred elements of the handle assembly cooperate with elongated slots provided in the panel of the equipment rack to permit the flow of air therethrough, especially for cooling purposes, while at the same time preventing ingress of rain or moisture due to the orientation of the louvres and also to prevent ingress of any foreign matter such as stones or small debris. The handle itself may serve as a radiation means to conduct heat away from the equipment rack and into the atmosphere.

Abstract: In a digital-to-resolver type converter for generating sine and cosine functions over at least a predetermined angular range wherein variation of the scale factor from absolute value is remarkably improved by modification of the reference input wherein the sum of the sine and cosine signals are fed back in a positive sense, providing more than a 30 fold improvement in reduction of scale factor variation in one preferred embodiment.

Abstract: A function generator for use in a synchro to digital (S to D) converter in which successive approximations of the digital output are made by switching between two chains of cascade connected operational amplifiers so that, as one chain is incremented to decrease the error signal appearing at the output of the chain, the other chain is coupled to control the error reduction operation until the aforementioned switching is completed, at which time the chains reverse roles.

Abstract: Method and apparatus for comparing and/or adjusting the frequency output of a frequency source, which method and apparatus is greatly simplified, and permits adjustment within a relatively short time interval and at a precision whose known difference is less than five parts in the 10.sup.12.The rubidium-controlled oscillator employed by the major networks to produce the 3.58 MHz subcarrier signal is utilized as a standard. Offsets made available at regular intervals by the National Bureau of Standards are utilized to indicate the frequency differences between the network standards and the United States Frequency Standard (USFS).