In this 2001 circuit we have the way to trigger an SCR with a phototransistor. The circuit appears elsewhere in this section, obtained from publications from different eras.
This circuit uses two oscillators to produce a sound that seems the sound of a ring-bell. The...
This circuit is used for remote current monitoring. In the original version of the 80s a lamp is...
We found this circuit in an old oscilloscope publication. With it, it is possible to observe the B...