This circuit with the 555, was obtained in a 90s American documentation. The signal must be applied to a good amplifier. The sound is similar to that of a police siren.
The voltage regulator circuit described is highly accurate and uses discrete components...
WWV is the standard frequency station of the United States government. This station broadcasts a...
Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then...