This oscillator-driver produces a deafening sound of about 3 kHz, modulated with a 10-Hz warble. BZ1 is a Matsushita EFB-RP3
4BZ. U1A and generate the 10-Hz waveform that modulates the 3-kHz tone that is generated by U1C and D, Ql drives the transducer through a 8-Q:l-kS2 transformer. R4 might require slight changes (Â±1 KOhm) to optimize sound intensity. Warning: Could cause hearing loss if improperly used.