A man machine interface for an A-C motor bypass has a membrane keypad with a multiplicity of pushbuttons connected to a micro-controller. The micro-controller controls the flow of current to the coil of each of the drive and bypass contactors to thereby open or close those contactors depending on if...http://www.google.ca/patents/US6316896?utm_source=gb-gplus-sharePatent US6316896 - Man machine interface for an A-C motor bypass
