This triac circuit turns on a load after a time of 8 to 80 seconds adjusted by potentiometer R7. The circuit is from a Radio Electronics from June 1970.
Found in Popular Electronics from the 1980s, this circuit can use more modern transistors such as...
This circuit is from a Radio Electronics from February 1970. The integrated circuit is an...
This is stage is transformer coupled and was found in na old publication of the year 1958. The...