This 555-based circuit was obtained from the 1995 Encyclopedia of Electronic Circuits volume 5. It triggers an SCR when the transistor is cut off.
This circuit can be used to receive signals from CB18636E and other modulated light transmitters in this...
Due to its low working voltage, this circuit of an old EDN can be associated with a...
We found this circuit in a 1983 English magazine, but it can be easily assembled with the BC548...