Abstract: An apparatus for and method of generating and linearly controlling periodic bipolar drive signals to drive an electromechanical device, such as a DC motor. The apparatus comprises side-by-side coaxial primary and secondary cylindrical commutators electrically connected together by a pair of diametrically opposed motor-driven brushes riding on the exterior surface of the commutators, each commutator having matched half-cylinder conductive sections separated by insulation at the common joints. The rotational position of the secondary commutator is adjustable relative to the primary commutator by a stepper motor mechanically coupled to it. A DC source is connected across the primary commutator and the electromechanical load is connected across the secondary commutator. Power of adjustable polarity duty cycle is commutated from the DC source to the load by the pair of rotating brushes.

Abstract: An improved electrostatic gyro system wherein, for each of the axes of suspension of a rotor, pickoff electronics are responsive to electrode pickoff signals for developing combined mass unbalance modulation (MUM) and servo signals from which a MUM signal reconstruction circuit demodulates and reconstructs only the MUM signal. The reconstructed MUM signal is then subtracted in servo suspension electronics from the combined MUM and servo signals to substantially develop only the servo signal containing only rotor displacement information. This servo signal is then fed to a servo network which does not require a notch filter. The output of the servo network is then developed into force signals to enable an associated pair of plate charge amplifiers to electrostatically suspend the rotor properly between an associated pair of electrodes.