The power transistor of this circuit can also be the TIP42 mounted on a good heat sink. The circuit is from old European documentation and the integrated circuit used is not very common today.
This basic configuration can be found in a lot of articles on this site. In this case, the relay...
This high pass filter was found in the February 1996 Electronics Now magazine. The circuit...
Found in General Electric documentation from 1967, this circuit uses an unusual PUT today. The...