Suggested by Mullard in an old documentation, this circuit is based on a common phototransistor and on transistors that may be the modern BC548.
This circuit was found in a 90s Electronics Now. The circuit can use a TIC106 for the SCR....
This circuit for a decorative robot was found in the April 1988 Radio Electronics magazine. The...
This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for...