Understanding Magnetic and Electrostatic Actuators Using Bond Graphs and a Mechanical Model

Magnetic actuators in relays, solenoids, and valve positioners and electrostatic loudspeakers and microphones store electrical and mechanical energy and are inherently nonlinear. They are harder to understand than transformer or gyrator transducers such as hydraulic pistons or voice coil drives which transduce power instantaneously and are essentially linear. Bond graph models show that magnetic and electrostatic transducers are mathematically analogous although electrically dual. An all-mechanical equivalent model shows the nonlinear behavior clearly and aids in the intuitive understanding of the problems associated with the use of such actuators.