Magnetic brake

Claim 1

A magnetic brake, comprising: a pair of frame members disposed in spaced parallel relation; a shaft member fixedly coupled to said pair of frame members on opposing ends thereof; a flywheel member rotatably mounted to said shaft member, said flywheel member having a cylindrically shaped wall extending axially from a first side thereof; a plurality of permanent magnets disposed on an inner surface of said cylindrically shaped wall, each of said plurality of permanent magnets being circumferentially spaced one from another; a stator support member coupled to one of said pair of frame members and extending into a cavity formed in said flywheel member, said cavity being defined by said cylindrically shaped wall; ferrite stator core means coupled to said stator support member for providing a magnetic circuit path; stator coil means mounted on said ferrite stator core means in spaced concentric alignment with said plurality of permanent magnets for generating an A.C. voltage responsive to displacement of said permanent magnets with respect thereto; a braking disc coupled to said flywheel adjacent a second side thereof for rotation therewith; a fan member coupled to said flywheel for rotation therewith, said fan member being disposed on said shaft member adjacent said braking disc; a driving member coupled to said flywheel for rotatable displacement thereof responsive to rotational displacement of said driving member; an electromagnetic ferrite core secured to said pair of frame members, said electromagnetic ferrite core having a gap formed therethrough, said gap being positionally located for passage of a perimeter portion of said braking disc therein; an electromagnetic coil disposed on said electromagnetic ferrite core for inducing eddy currents in said braking disc responsive to a current flow in said electromagnetic coil to thereby generate a braking torque; a rectifier circuit electrically coupled to said stator coil means for converting said A.C. voltage to a D.C. voltage; a first voltage regulator circuit electrically coupled to said rectifier circuit for providing a substantially constant voltage signal on a first output thereof, said first output of said first voltage regulating circuit being electrically coupled to said electromagnetic coil for supplying said substantially constant voltage signal thereto; a digital-to-analog converter circuit electrically coupled to a second output of said first voltage regulator circuit for supplying power thereto, said digital-to-analog converter circuit having a digital input for receiving an externally applied digital control signal and an output for providing an analog control signal representative of said digital control signal; a second voltage regulator circuit electrically coupled to said digital-to-analog converter output for smoothing said analog control signal; and, a current regulating circuit electrically coupled to said electromagnetic coil and to an output of said second voltage regulator circuit for controlling a magnitude of said current flow through said electromagnetic coil responsive to said smoothed analog control signal, whereby said magnetic braking torque has a selected magnitude responsive to a predetermined value of said digital control signal input to said digital-to-analog converter.