This circuit turns off after a time given by capacitor C1. This component can have from 1 to 1,000 uF depending on the desired time. The circuit is from an Electronics Now from June 1995.
This simple receiver picks up local MW stations with playback on a small speaker. The antenna must...
This circuit deactivates the ignition system after a certain time when you leave the vehicle. In...
This conventional humidity or water alarm circuit was found in an English documentation from 1974....