This is the traditional configuration of a standard lamp with a rectifier. Only incandescent lamp can be used and for the rectified version a 5 W lamp.
This circuit, from an old publication from the 1970s, can be made with silicon transistors like...
Found in a 90s Popular Electronics, this circuit excites a 40 kHz ultrasonic transducer. The...
This circuit with signal acceptance filter was found in the June 1993 Electronics Now magazine. Other...