This circuit was found in an American documentation from the 80's. The components are from that time. It provides a variable output of 18 to 30 V with a current of 200 mA.
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....