This dual-LED circuit indicates three signal levels. It was found in the January 1996 issue of Electronics Now magazine. The integrated circuit may be an LM339 or another comparator.
September 2017 - Broadcom's AEAT 8800 Q24 magnetic encoder can be obtained from Mouser...
This circuit uses a 555 (according to the diagram) to generate 50 ms tone bursts at a frequency of 1.5...
We found this mains-powered switch circuit in Electronics Now magazine from July 1994. It could be...