This sophisticated repellent uses a double 555. We find it in an American documentation from the 80's. The circuit can be powered by batteries or source included in the diagram.
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...