A touch-operated switch for electrical apparatus which includes a power connection to the apparatus, a serially connected power socket in the connection provided with a pair of terminal jacks each in the form of make-before-break electrical contacts, a plug-in module containing an electronic circuitry...http://www.google.es/patents/US4237386?utm_source=gb-gplus-sharePatente US4237386 - Plug-in module for touch control switching
