Patent ID: 7952366
Filing Date: 2011-05-31
Classification: G01R,G06F,G08B,H03K

Abstract:
1. A sensor for determining the presence of an object comprising: a sensing element; a capacitance measurement circuit operable to measure the capacitance of the sensing element; and a control circuit operable to determine whether the object is in proximity with the sensor based on a measurement of the capacitance of the sensing element, the control circuit further being operable to provide an output signal to control a function of an apparatus when it is determined that the object has not been in proximity with the sensor for a predetermined time duration, wherein the control circuit includes a time input terminal and the predetermined time duration is selectable from the number of different predefined time durations according to a voltage applied to the time input terminal, and wherein the control circuit includes a delay multiplier terminal and is configured so that a selected one of the number of different predefined time durations is multiplied by a multiplication factor according to a voltage applied to the delay multiplier terminal to provide the predetermined time duration.