This circuit was found in an American 1990s documentation. It can directly trigger a triac when light is detected by the sensor. The integrated circuit is common, like the 741.
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...