Electrical drive for a segmented transducer

Abstract

An electronic system is provided for stimulating a segmented transducer with resonant electrical signals to produce a nonsinusoidal transducer output. In an illustrative embodiment, the transducer comprises a segmented piezoelectric actuator. The actuator comprises stacked piezoelectric dimorphs forming the actuator segments, each of which reacts electrically as a capacitance. Each segment (capacitance) is connected in a loop in electrical series with an external capacitor or a corresponding segment of a second actuator. An electrical controller stimulates each loop with a separate resonant electrical signal related to the others in frequency, phase, amplitude, and polarity. The resulting output of each actuator is the vector sum of the mechanical outputs of the individual dimorphs of that actuator. In an ideal resonant drive system for a segmented transducer, the only electrical energy used is that which is converted directly to mechanical work by the actuator. All other temporarily stored electric and elastic energy is recycled within the loops for high efficiency. When the electrical waveforms drive a pair of actuators, electrical charge oscillates between the actuators. Thus, loop currents flow between essentially lossless reactive components rather than through high-loss output devices.