The selected circuit is from the Texas Instruments optoelectronics manual. With it you can receive optical signals in CW. Transistors support equivalents.
This little-known regulator today was found in a Radio Electronics circuit from December 1978. The...
This indicator circuit used and game machines (arcades) to indicate that the machine is being...
This sophisticated timed sonic switch was found in a 2001 documentation. It has a timer with a...