This circuit was found in Motorola documentation from the 1980s. The components are of the time, not currently common as operational and opto receiver.
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....