This circuit was found in a 90's EDN. The circuit provides two 15 V outputs and one 5 V output from the 12V voltage of a car battery. The components are from that time.
This circuit is from a 1980s Motorola documentation. The circuit can be made with modern...
This well-known circuit triggers a relay when light striking the phototransistor is cut off. The...
This circuit generates a pulsed tone whose frequency depends on C2 and whose flashing depends on...