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.
Originally, this 2000 documentation circuit was created to operate as a sensor for the parallel...
This multi-purpose power supply provides voltages of +15, -15, 300 and 1 000 V and is very useful on...
This circuit was found in a Popular Electronics of the 1990s. The sensor is a rotating mechanical...