This sonic control circuit for a small robot turtle was obtained in an American documentation from 1967. The circuit uses a ceramic capsule to fire an SCR.
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...