This circuit is from 1985 documentation. The integrated circuit is not very common today, but modifications can be made leading to a project with current integrated circuits.
This circuit is from a documentation from the 90s. The transistor can be any general-purpose FET...
Found in an Elektor from the 90's, this double door-bell drive circuit switches a relay by...
Using a CA3130, this circuit generates signals from approximately 550 kHz to 1.6 MHz using a...