This circuit is from the 80's, using an integrated of the time. The circuit serves as a reference, as this type of dialing is no longer used today.
This separator filter is from an old publication. The capacitor can have 10 to 47 uF of the...
This simple circuit turns on a small lamp (or LED) when the light stops shining on the sensor for...
The first purpose of this game from a 2001 publication is to pass the stick between the rings,...