Switch circuit provided with means for setting up the initial condition thereof

摘要

In a switch circuit, there are provided a signal input stage comprising an array of switches paired with pilot lamps; a storage circuit comprising I2L elements for storing a signal derived from the signal input stage; a circuit for causing that one of the pilot lamps be lit which is associated with a predetermined one of the switches; electronic switches for controlling a signal source in response to the signal derived from the signal input stage; an auxiliary current source circuit for holding the memory at the storage circuit when the main power supply is interrupted; and a circuit adapted, when the capacity of the auxiliary current source circuit is decreased and when the main power is supplied, to turn on a predetermined one of the switches while turning off the remaining ones of the switches, thereby setting the storage circuit to a predetermined initial condition.