Patent ID: 6559758
Filing Date: 2003-05-06
Classification: G08B

Abstract:
A sounder device comprisinga piezoelectric resonant transducer; an amplifier means with a coupling transformer means to drive the transducer; an electronic signal means to provide an input signal to the amplifier means; with the electronic signal means further comprising two or more lower frequency pulse oscillators; a logical â€œORâ€  circuit means, with inputs from each of the lower frequency pulse oscillators; a resonant frequency pulse oscillator means, with a higher frequency near or at the resonant frequency of the transducer, and with a pulse width optimized to produce the maximum acoustic output from the transducer; a logical â€œANDâ€  circuit means with a first input connected to the output of the logical â€œORâ€  circuit means, a second input connected to the output of the resonant frequency pulse oscillator, and with an output connected to the amplifier input.