Revolving valve for feeding air pulses to a resonance tube for generating low-frequency sound and a method for feeding these pulses in an optimal way

A revolving valve, consisting of a stationary outer cylinder, and an inner revolving cylinder, with at least one through hole, for supplying pressurized air pulses to the rear end of a quarter wave resonance tube, for generating a standing low-frequency sound wave in said quarter wave resonance tube,

• wherein said through hole is arranged such that the pressurized air pulses passing through said through hole when the inner cylinder revolves supply maximum in-put power to said standing low-frequency sound wave by feeding said pressurized air pulses only during the time intervals of the oscillation cycles of said standing low-frequency sound wave when the air pressure in said rear end of the quarter wave resonance tube, is positive.