EntityQ1713498· pop 7· linked from 95 articlesstepping switchSign in to saveelectromechanical multi-pole switch controled by a chain of pulsesConnectionselectrical switchEntityWorld War IIConceptrelayEntitythermostatEntityrailroad switchEntitymultiplexerEntitycryptanalysisEntityelectromechanicsEntityBletchley ParkEntitycounterEntitytelephone exchangeEntitytelephone callEntitypush-buttonEntitypressure switchEntityReed switchEntityspark gapEntityrotary dialEntitykill switchEntitylimit switchEntitypulseEntityCategoriesAmerican inventionsSwitchesTelecommunications equipmentTelephone exchanges