Abstract: An improvement in torque control systems for reaction wheel assemblies and the like used primarily for stabilizing space vehicles such as satellites including means for integrating the torque command signal and combining the integrated torque command signal with a feedback signal proportional to the angular speed of the rotor of the reaction wheel assembly thereby producing an error signal proportional to the difference between the integrated torque command signal and the angular speed signal. The error signal is coupled to the rotor spin motor which produces a resultant output torque that has been compensated for disturbance torques and other anomalies whereby the resultant torque applied to the rotor and consequently to the satellite is substantially equal to the commanded torque.

Abstract: In an azimuth reference system including a flux valve coupled to a synchro stator and a directional gyro having its outer gimbal mechanically coupled to the synchro rotor, a low power electronic slaving circuit having its input electrically coupled to the rotor of the synchro and its output coupled to a torquer for slaving the directional gyro into synchronism with the flux valve. The low power electronic circuit includes a phase compensated amplifier coupled between the synchro rotor and a demodulator for producing a bipolar slaving error signal which is coupled through a high gain amplifier to parallel connected coils in the torquer. A threshold detector circuit responsive to the speed of the gyro rotor controls a limiter feedback circuit in the high gain amplifier thereby limiting its gain when the gyro rotor has attained a predetermined speed.

Abstract: A brush and slip ring assembly in which specific resilient characteristics are developed in the brushes by forming them in shapes which will allow the brushes to be simultaneously displaced a finite amount with the slip ring assembly in a vibratory environment which would otherwise produce relative sliding motion therebetween. By preventing the relative sliding motion between the brushes and slip ring assembly, the formation of electrically insulating friction polymers on the points of contact between the brushes and slip rings is inhibited.