Macrosonix Corporation

F Joseph Keith

Timothy S Lucas

Thomas W Van Doren

Christopher C Lawrenson

Motor control of a variable reluctance motor is obtained by providing a periodic voltage waveform to a coil of a motor. No coil current control or current or flux feedback is needed to obtain flux waveforms that allow for low-distortion or distortion-free operation of the motor. The periodic voltage waveform may be a sinusoidal or sawtooth signal, for example, and has a substantially zero mean for each cycle of the signal. The periodic voltage waveform may be offset to compensate for the resistance of the coil, and the coil current may be monitored in order to determine the amount of offset required. By providing a zero-mean or substantially zero-mean periodic voltage waveform, the coil current and flux in the gap between the core and the moving part are guaranteed to reach a zero value at some point during each period (or cycle) of the periodic voltage waveform.

High stability dynamic force motor

A vibrational acoustic unit comprises a dynamic force motor, a power take-off spring having one end attached to the dynamic force motor and the other end attached to a fluid filled acoustic resonator. The motor oscillates the entire acoustic resonator so as to excite a resonant mode of the acoustic resonator. A method of delivering power to an acoustic resonator comprises resiliently connecting a motor to the resonator, and driving the motor to oscillate the entire acoustic resonator so as to excite a resonant mode of the acoustic resonator.

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Richmond, VA, United States of America

F Joseph Keith