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 integrated circuits used in this 1999 project are not very common today. However, they can be...
This 3-digit thermometer, suggested by Texas Instruments, uses 3 integrated plus the display, with...
This circuit is from the National Semiconductor FET Databook. The coil data is provided with the...