SENSOR FOR ILLEGAL TOUCH ON MEMBRANE SWITCHES
Original Publication Date: 1987-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
Membrane and capacitive switches often operate to give continuoushon-discrete output. A one dimensional switch is shown in Figure 1 (2 dimensional devices are more common and work in like manner). The physical position on the switch arrow is proportional to output voltage. R2 is very high. However, if two positions are selected, the output voltage is ambiguous. Two methods for detecting this problem are shown in Figure 2.