throw a switch/handle/lever
From Longman Dictionary of Contemporary Englishthrow a switch/handle/leverthrow a switch/handle/leverSWITCH ON OR OFFto make something start or stop working by moving a control He threw a switch and the lights all went out. → throwExamples from the Corpusthrow a switch/handle/lever• The image of Chantal vanished instantly as though some one had thrown a switch.• He threw a lever and the twin 1500-horsepower engines roared to life.