A Manual Device for Locating Electric Arc-Producing Faults

摘要

The purpose of the program is to develop a noncontacting portable instrument for locating defective components and circuits which generate RF fields. Initial effort was concerned with a study of the RF spectrum generated by various defective components and circuits. The spectrum was found to be rich in RF noise in the vicinity of 26 megacycles. Accordingly, a portable broad band 26-megacycle radio receiver and associated RF pickups were developed. The receiver was designed for the highest gain and the lowest noise figure attainable in a portable device. Several RF pickups were designed to provide a moderately directional means of coupling to both RF voltage fields and RF current fields. The effectiveness of this equipment was evaluated using specially constructed sources of localized RF fields. The equipment was also used for locating simulated defective circuits and components as well as actually defective circuits and components. These experiments show that circuit and component defects resulting in an electric spark discharge can usually be detected by the receiving equipment. The results also show that extremely low level RF disturbances, such as those generated by noisy diodes, usually cannot be detected by the receiving equipment. (Author)