Patent ID: 7081699

Claim:
A thermoacoustic generator comprising: a housing containing a working volume of gas with a pressure; a thermoacoustic core supported in the housing and having a first heat exchanger and a second heat exchanger, the thermoacoustic core operable to introduce acoustical power into the housing thereby oscillating the pressure of the gas at a frequency; and a piezoelectric alternator supported in the housing and having a race that is movable when acted on by acoustical power, the alternator further including a portion of piezoelectric material operable to produce electrical power when acted on by a stress, the portion or piezoelectric material being in mechanical communication with the movable face such that movement of the face stresses the portion of piezoelectric material so as to produce electrical power; the thermoacoustic core, the gas and the alternator defining a resonating system with a resonating mass operable to resonate at the pressure oscillation frequency; the alternator having a moving mass that serves as a substantial portion of the resonating mass inside the housing such that the moving mass substantially reduces the pressure oscillation frequency of the resonating system as compared to a system without the moving mass.