Integrated circuitry projecting and controlling electrical appts. - has voltage limiter delivering pulse signal to counter if mains voltage is applied in-front of main switch

摘要

A first voltage monitoring circuit (3) resets the counter upon raising of the voltage before the main switch after mains interference. A first AND gate (10) delivers reset pulses for the counter (2). A signal obtained in the control circuit (4), from the presence of the mains voltage behind the main switch at the output (Q) of the ocunter (2), indicates whether the counter (2) has reached its final position, thus connecting the AND gate. Reset pulses are supplied to the counter (2) so long as it has not reached its final position and simultaneously the mains voltage is available behind the main switch (1) and the electronic control circuit (3) only controls the appliance if the counter (2) has reached its final position. USE/ADVANTAGE - e.g. machine or oven. Prevents automatic starting up of appliance after power has been restored following mains failure, although mechanical switch is in 'on' position.