Abstract: A step data to synchro converter for coupling one of a plurality of different step data transmitters to one of a plurality of different synchro receivers. The output of the step data transmitter is applied to an interface circuit and processed into a three bit binary code suitable for actuating a plurality of switching means. The switching means selectively apply an in-phase and an out-of-phase output of a transformer, which is responsive to the synchro receiver's reference voltage and frequency source, to a plurality of transformers associated with the input stator windings of the synchro receiver. The output of the plurality of transformers is a drive signal which satisfactorily approximates synchro data.

Abstract: A synchro-to-step data converter for coupling one of a plurality of different synchro transmitters to one of a plurality of different step motors. The three wire output data of a synchro transmitter is demodulated into a three bit binary step data code and is applied to digital decoding means. The digital decoding means converts the step data code into a format suitable for application to a particular step motor and/or compensates for the speed of the synchro input shaft relative to the step motor output shaft.

Abstract: An apparatus for providing the operator of a marine vessel with an alarm when when a malfunction occurs in the steering system of the vessel. The apparatus utilizes a closed loop simulator to simulate the rudder position, and a comparison of the simulated rudder position to the actual rudder activates the alarm when a predetermined threshold value has been exceeded. Appropriate time delays during which the alarm is disabled make the apparatus adaptable for use with steering systems having a steering gear which has rate inconstancy, and a shaping circuit makes the apparatus adaptable for use with steering systems having a steering gear which has static positional nonlinearity.

Abstract: An illustrative embodiment of the invention provides a ship's steering system or helm adapted to provide a control signal to the ship's rudder such that the response of the rudder to the rotation of the helm is substantially non-linear from hardover to hardover wherein a portion centered about midship is linear such that hardover to hardover rudder can be ordered in less than one turn of the wheel. That is, less rotation of the wheel is necessary when large helm or rudder orders are required for heading changes and a greater rotation of the wheel about midships is necessary to desensitize rudder changes to large wheel rotations in order to make heading keeping easier.