This humidity sensor indicates the different levels of conduction of the sensors through an LED bar. The circuit is from Popular Electronics and must be powered by cells or battery.
This circuit triggers a relay when the phone rings. An application is like remote doorbell. The circuit...
This simple CMOS circuit generates two-frequency signals for use as a signal injector. The circuit...
With a mains-rated transformer and 1:1 winding this benchtop circuit was found in the January 1995...