This circuit produces the sound of percussion such as blocks, drum, bell, etc. The frequency depends on the marked capacitors, which can have a wide range of values depending on the desired sound.
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....