Suggested by General Electric documentation from 1968, this circuit activates a relay after 60 seconds, keeping it closed. PUT is an uncommon component today.
I found this circuit on a December 1976 Radio Elettronica. The Italian magazine no longer exists, but...
This circuit for the power grid was found in the June 1969 Radio Electronics magazine. The load is...
This circuit with common CMOS components was found in the November 1984 issue of Radio Electronics...