Abstract: An improved servo system for galvanometers, scanners and similar devices which uses digital processing to increase the dynamic range and provide greater effective resolution. The system provides digital control of a reference point that directly influences the excitation, which in turn directly influences the gain of the circuit. A high and low resolution switching path is provided to optimize dynamic range. Wide angle torque compensation improves uniformity of response at large angular deflections from zero. Improved thermal protection allows safe operation near system thermal limits. A graphical user interface allows adjustments and changes response on the fly for tuning due to input conditions or user control.

Abstract: A reciprocating rotary action actuator consisting of a rotor and stator that can be added to a bi-directional rotary motor or galvanometer scanner, where the stator has a ring magnet and a pair of soft iron pole pieces that concentrate the flux of the ring magnet into a concentric set of narrow, uniformly spaced, axially oriented, magnetic flux fields intersecting the rotor's field of travel. The rotor has small permanent magnets embedded in the periphery of a nonconductive, nonmagnetic rotor core. The rotor magnets have the same number and spacing as the stator's magnetic flux fields. The magnet poles are oriented opposite the flux fields of the stator pole pieces, so that upon rotation, the rotor magnets encounter the stator flux fields at each end of rotor travel, creating an opposing force that reverses the angular direction of the rotor with minimal requirement for actuator current and generation of thermal losses.