Found in a PE Hobbyst Handbook of 1991, this circuit was originally proposed to time photographic baths in developing rooms but can be used for other purposes. The circuit beeps at 30-second intervals.
May 2017 - A revolutionary new Intel memory can now be purchased from Mouser Electronics, with the...
This traditional transistor source uses only two transistors found in a 1998 documentation. The...
We found this circuit in a 90's European schematic. The circuit can be implemented with almost any...