Abstract: A control system comprising a control input device having a movable magnet, a pole-piece frame arrangement positioned about the magnet and positioned therein at least two magnetic flux sensors for sensing movement of the magnet in a given direction. The control system further comprises a monitoring arrangement for monitoring the output signal of each of the sensors and permits the input device to control the system only when the output of the sensors are within a predefined range. This multiple sensing provides a fail-safe in the event that one of the sensors generates an erroneous signal.

Abstract: A method of measuring capacitance is provided in which measurement speed is increased by as much as two orders of magnitude by optimizing timing parameters to rapidly charge and discharge the capacitor in small increments about an equilibrium voltage. The capacitor is charged at a linear rate by applying a predetermined constant current thereto, and discharged at an exponential rate determined by the RC time constant in the discharge path. Incremental charge and discharge times are selected in such a manner that results in an equilibrium voltage at a point where the charge voltage ramp and discharge voltage curve would cross if they were superimposed on one another. By appropriate selection of the incremental charge and discharge times, the equilibrium voltage may be conveniently established at a point well within the range of a measuring analog-to-digital converter (ADC). The voltage difference over the incremental charge time may be measured on one cycle and utilized to compute the capacitance value.