This circuit was obtained in a 1967 Raytheon manual. The company's component is an optical coupler with a photo-resistor and a lamp. Transistors support equivalents.
We found this circuit in the August 1994 issue of Electronics Now. The 4046 is unusual today. The...
This twisted pair exciter circuit uses 80's components. The circuit is from a documentation of the time, but...
Using a 4046 PLL, which is uncommon today, this circuit was found in the October 1994 issue of...