Abstract: A meter dial register encoder employs a plurality of photoresistor sensors in a row and column matrix configuration. A microcomputer selectively scans the photoresistors to determine whether they are illuminated or non-illuminated. Each column of the row and column matrix contains a scanned photoresistor and a plurality of unscanned photoresistors operated in a two-or-three-out-of-five code, with one terminal of the scanned photoresistor being selectively connected to a 5 volt source by a microcomputer, the other terminal of the photoresistor being connected to the column conductor. The unscanned photoresistors of the column are connected between the column conductor and a separate terminal of the microcomputer held at ground potential. The column conductor is supplied to one terminal of a two terminal comparator, the other terminal of which is connected to a source of reference voltage.

Abstract: A remote meter reading system includes a dial register encoder and a pulse encoder both coupled to the same rotary disc of our induction watthour meter. A first electronic data register stores the non-volatile dial register encoder output, and a second electronic data register stores a value consisting of an initial value set by the dial register encoder at start-up time continuously augmented by the output of the pulse encoder since start up. Comparison and selective readout of the two electronic data registers reduces erroneous meter reading outputs.

Abstract: An encoder includes an array of variable resistance photosensors responsive to variations of incident illumination. The array is interconnected in a row and column matrix having row inputs connected to a sampling control device for sequential application of a predetermined voltage to the inputs. The matrix column outputs are connected to a detecting circuit having a current-measuring detector for receiving sensing currents from the outputs and for producing current responsive detection signals in response to the application of the predetermined voltage at the inputs. The outputs are held at a constant voltage, thereby providing effective isolation between the column outputs and eliminating interaction between elements connected to adjacent columns without the need of additional isolation means, such as isolation diodes, at each matrix intersection.

Abstract: A light distribution system for optical encoders includes a light guide plate and a light input coupler for distributing input incident radiations into the light guide plate as a flat distributed beam of beam segments intercepted by a pattern of discrete light output couplers reflecting narrow output beams for providing a uniform pattern of encoding illuminations.

Abstract: A low energy mechanically driven and electromagnetically actuated ground fault trip indicator is taught. The ground fault trip indicator utilizes the magnetic flux of a permanent magnet in a first flux path to maintain a movable armature biased against a spring. An electromagnet is disposed to provide magnetic flux in opposition to the magnetic flux of the permanent magnet. The electromagnet is not energized for providing the opposing flux until a pulse is received from an appropriate ground fault trip detecting circuit. When the appropriate pulse of energy is applied to the electromagnet, a portion of the flux of the permanent magnet is cancelled allowing the spring to force the armature into a new position. In this position the flux of the permanent magnet is reestablished in a second flux path. When the indicator is in the latter position indication of the occurrence of a ground fault is given.