In the figure we have a simple way to produce tone in a piezoelectric transducer. The frequency depends on the capacitors and the supply can be done with voltages from 1.5 to 6 V.
This sole beacon which has a battery charged by photocells was found in documentation from 1991....
The supply voltage of this circuit can be between 4 and 20 W. The power depends on the voltage and the...
This 555 IC circuit was found in the November 1994 issue of Radio Electronics magazine. The...