Abstract: A portable uncoupling device comprising a raised resilient strap attached to a self locating base and used to uncouple miniature railroad cars where the two couplers connecting two railroad cars each have one lift pin located on opposite sides of the centerline running between the rails of a miniature railroad track. The raised resilient strap is secured at one end to the self locating base, the other end of the strap touching the base but being able to slide freely along it so as not to buckle as the raised straps is depressed. The base has crimped ends to secure it between two railroad ties and sufficient width to allow it to fit snugly between the rails. The resilient strap has a width slightly greater than half the width of the base and is positioned so that it lifts only one lift pin of two connected couplers and provides support below the center of mass of the railroad cars passing over it.

Abstract: Three electrically isolated photosensitive diodes on a common substrate are located directly behind a multilayer dielectric coated mirror that is one of the reflective elements of a ring laser. A small percentage of the beams incident on the mirror is allowed to pass through and strike the photosensitive diodes. Two of the diodes are masked in such a way as to detect the heterodyne beat signal of two counterrotating beams in the ring laser and generate an output signal used to determine rate of rotation of the ring laser body. The third diode sums the intensity of the counterrotating beams and generates an output signal which goes to a feedback cavity length control circuit.