This simple circuit for headphones or small speakers was found in documentation from the 90s. The circuit works with voltages from 5 to 9 V and has good gain.
This circuit causes an LED to flash at a frequency determined by capacitor C1. The circuit can be...
This flasher or neon signal powered by batteries was found in old documentation. The transformer must...
This circuit was obtained from an ancient American documentation, but appears elsewhere in this...