A synthetic voltage division controller to extend the stable operating range of parallel plate actuators

The parallel plate actuator is utilized in many applications, but its open loop stable range of motion is limited to 1/3 of its maximum range of motion. Numerous controllers have been implemented to extend the stable range of motion. One well known technique for accomplishing this goal is the series capacitor method. However, this method possesses several negative attributes: a very high input voltage, a very small discrete capacitor and sensitivity to parasitic capacitance. Synthetic voltage division (SVD) emulates the series capacitor method utilizing a linear feedback controller and overcomes the negative attributes of the series capacitor method. A prototype SVD controller was successfully analyzed, designed, fabricated and tested using a parallel plate actuator emulator.