This operational amplifier circuit with variable gain was obtained in an 80's Electronic Engineering. The circuit applies to other operational amplifiers.
Found in a 90s Popular Electronics, this circuit triggers a relay in case of overvoltage. Can be used as a...
This circuit generates approximately 30 Hz signals from a 3.3 kHz clock. The circuit was found at...
This circuit was obtained from the 1976 Siemens integrated circuits manual. It is the circuit for...