This circuit makes use of an integrated LM2907. The circuit is from an old documentation being applied to cars that still used platinum, common at the time.
This egg timer has been found in an English magazine that no longer exists in 1982. The...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...
Found in Popular Electronics from the 1980s, this circuit uses two operational amplifiers from...