Patent ID: 11934595
Assignee: LOGITECH EUROPE S.A.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 3:
4. A user input device, comprising:
a rotary input control, comprising:
a wheel;
a magnetizing coil;
a first permanent magnet extending through the magnetizing coil;
a second permanent magnet, the first permanent magnet and the second permanent magnet being configured to set a resistance profile for the wheel by cooperatively emitting a magnetic field that is operable to oppose rotation of the wheel; and

a control system configured to switch between three or more different resistance profiles of the wheel by varying an amount of electrical current supplied to the magnetizing coil,
wherein at least two of the three or more different resistance profiles are of a same polarity and within a linear torque region of the first permanent magnet,
wherein the linear torque region of the first permanent magnet is between a minimum and maximum magnetic flux state for the first permanent magnet,
wherein the control system modulates the amount of current supplied to the magnetizing coil based on a generated error signal corresponding to a difference measurement between a current supplied to the magnetizing coil and a new current setting; and
wherein the control system recalibrates an amount of current supplied to the magnetizing coil in a first state by measuring a rate of decay of an RPM of the wheel and using the rate of decay to establish a new baseline resistance.