The selected circuit is from the Texas Instruments optoelectronics manual. With it you can receive optical signals in CW. Transistors support equivalents.
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...
This automatic dimmer for incandescent lamps was found in a European publication from the 1980s. The...
This traditional doubler configuration with the 555 can be found in other articles on the author’s site....