This circuit was taken from an article in Electronics Now magazine in February 1995. The power supply must be dual and other operational amplifier can be used.
This simple timer, which activates an LED indicator, but which can be modified to activate a...
This circuit was obtained in a documentation for radio amateurs in 1974. The coil consists of 12...
This circuit was found in a 1973’s Japanese magazine. It uses transistors of the time and is...