This circuit uses three inverters to generate a rectangular signal whose frequency depends on R1 and C1. The circuit is from a March 1996 Electronics Now.
Presence Detector (CB18741E) The original name of this project found in documentation from the 90s...
The circuit shown is the receiver for the CIR5645S, also suggested by National Semiconductor. The...
E) We found this circuit in a PE Hobbyst Handbook from the 90s. The components are common, except...