Delayed response touch switch controller

Abstract

The present invention provides a very low actuation force touch control switch for use in brightness control of illumination devices. The control switch comprises a flexible membrane having a plurality of conductors disposed on one surface and secured to a rigid support surface. The conductors are interwoven in a present pattern with portions of the conductors being exposed. A conductive surface is formed in an area under the exposed conductors. The membrane is fastened to the rigid support surface so that a very small spacing is maintained between the exposed conductors and the fixed conductive surface, allowing a very light touch to cause one or more exposed conductors to be shorted to the conductive surface. A microprocessor periodically polls the leads of the membrane to determine which are shorted together and causes an output power level to be adjusted accordingly. The touch control system employs a Delayed-Off feature in which the microprocessor causes a discernible dimming to occur when a DELAYED-OFF selection are on the memberane is pressed but which delays the turning off of the illumination device until a preselected amount of time has passed, thereby allowing a switch operator to leave an area before becoming dark. In addition, Soft-On and Soft-Off processing is employed so that on and off transitions are more gradual and aesthetically pleasing and to provide a period in which to select an alternate brightness level.