This circuit was found in an 80s Hands On Electronics. It senses the water level in a reservoir by driving a pump when needed.
This circuit was found in an English operational documentation from 1970. The circuit can be...
This circuit is from a 1974 publication. It generates a pulse with several sinusoidal cycles from...
This solar cell driven circuit makes 4 LEDs run at a speed given by capacitor C2. The circuit is...