This circuit was found in a Popular Electronics from the 90's. The components used are common and instead of the buzzer we can use an LED or a relay.
Found in Datel's documentation from the 1980s, this circuit makes use of the company's operational...
We found this passive circuit in the February 1995 Electronics Now magazine. The circuit is...
This circuit was obtained in a 1977 documentation. Two operational amplifiers 741 provide an input...