Patent ID: 6087743
Filing Date: 2000-07-11
Classification: H02K

Abstract:
A mechanical actuator positioning system comprising:(a) a magnetically actuatable movable element;(b) a spring connected to the movable element to spring bias the movable element;(c) a drive coil coupled to the movable element to apply a magnetic force to the movable element against the force of the spring as a function of the current supplied to the drive coil;(d) a sensing coil coupled to the movable element that changes its effective inductance as a function of the position of the movable element;(e) a variable oscillator incorporating the sensing coil in a resonant circuit to control the frequency of oscillation of the output signal of the variable oscillator as a function of the inductance of the sensing coil;(f) a reference oscillator providing a reference output signal at a selectable frequency; and(g) a phase detector receiving the output signals from the variable oscillator and the reference oscillator and providing a pulsed output signal related to the difference in phase and frequency between the two signals, the output signal of the phase detector connected to provide drive power to the drive coil.