Abstract: Method for determining a present coil temperature of a coil of a magnetorheological (MR) damper of an operating automotive vehicle, wherein the coil is powered by an output of a controller connected to the coil through a conductor. One step includes calculating a coil-plus-conductor resistance from the voltage and the current of the output of the controller when the controller applies a test current to the coil and the conductor. Another step includes calculating the present coil temperature using at least the coil-plus-conductor resistance and compensating for the resistance of the conductor.

Abstract: A watercraft seat suspension includes a damper mounted between a watercraft seat and the watercraft hull. The damper includes an electrically actuated mechanism controlling fluid flow from a first chamber to a second chamber within the damper. A sensor senses motion of the seat relative to the hull. A control unit interpolates the sensor signal and develops an actuating signal controlling the electrically actuated mechanism. In one arrangement, the electrically actuated mechanism is a solenoid actuated by the actuating signal to effect one of two different damping modes. In another arrangement, the electrically actuated mechanism includes a conductor coil and flux ring generating a magnetic field proportional to the actuating signal to vary the viscosity of magneto-rheological fluid in the damper.

Abstract: A watercraft seat suspension includes a damper mounted between a watercraft seat and the watercraft hull. The damper includes an electrically actuated mechanism controlling fluid flow from a first chamber to a second chamber within the damper. A sensor senses motion of the seat relative to the hull. A control unit interpolates the sensor signal and develops an actuating signal controlling the electrically actuated mechanism. In one arrangement, the electrically actuated mechanism is a solenoid actuated by the actuating signal to effect one of two different damping modes. In another arrangement, the electrically actuated mechanism includes a conductor coil and flux ring generating a magnetic field proportional to the actuating signal to vary the viscosity of magneto-rheological fluid in the damper.