This circuit uses a PLL4046 oscillator to excite a piezoelectric ceramic. The circuit is from an October 1994 Electronics Now magazine.
This circuit was obtained from an American publication of 1982, but can be easily assembled today...
This circuit was found in a 90's Electronic Design. The circuit can be adapted to use modern...
This 80's circuit uses a microcontroller programmed to generate various songs. The circuit can serve...