This circuit is from a 1967 publication. The configuration holds true for modern transistors having a feedback across R2.
EDN magazine in a 90's issue published this TTL technology debouncer flip flop circuit, in this...
This circuit is from Radio Shack documentation from 1977. It aims to demonstrate the principle of...
We found this circuit in a 1991 publication. It indicates when an analog phone line is busy by...