Found in a 70s RCA transistor manual, this circuit is recommended for mass-positive cars of the era. The transistor is for general use.
This circuit, found in documentation from the 1980s, uses an operational amplifier from that time....
This low frequency sinusoidal oscillator was obtained in documentation from the 1970s. Operational...
This circuit was found in a 1980s documentation. It is intended for remote vibration monitoring...