The figure shows how to obtain a digitally programmed resistance using the 4066. The circuit is from a Radio Electronics from November 1989.
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...