This circuit that emits siren sound can be used in a fire alarm. We found it in an old American documentation. The signal must be applied to a good audio amplifier.
In the figure we have a simple circuit to measure the current in an electronic device and thus...
May 2017 - Mouser Electronics is already in stock with the new BCP1395 transistors from Nexperia....
The integrated circuit is the 4093 and one of its four gates is used. The frequency is given by...