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 three-transistor circuit was found in Radio Electronics magazine from May 1969. The circuit is...
A stereo digital mixer using the 4053 is built as shown in figure bellow. The IC must be powered...
The circuit shown is from a 1994 National Semiconductor documentation and can be implemented with...