This circuit, which can act as a shield, was found in a 1990 PE Hobbyst Handbook. The circuit generates logic pulses for different types of applications.
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...