This circuit triggers an alarm in the event of a power failure. The circuit is from an 80's documentation, being powered by 9 V battery. The parts are common today.
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....