Electro-acoustic transducer
AssigneeSiemens Aktiengesellschaft
InventorErwin Martin
Life of this patent
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Abstract
An electrical acoustical transducer is provided having a piezoelectrical layer in a housing with a transducer plate. The transducer plate divides the housing into a front chamber and a rear chamber. In the rear chamber, there is provided a Helmholtz resonator for the attenuation of resonance increases. With the invention a Helmholtz resonator is designed such that its acoustical characteristics do not change through environmental influences. Instead of covering the resonator by means of a customary silk disk, several narrow slots are arranged in the carrier plate.
Claims7
An electro-acoustic transducer, comprising:
- a transducer plate arranged in a housing and by which a space in the housing is divided into a front chamber and a rear chamber;
- a fitting which closes off the front chamber;
- at least one Helmholtz absorption resonator means arranged in conjunction with a plate in the rear chamber for attenuating rises in resonance;
- the Helmholtz resonator means comprising a cylindrical collar zone having one end closed off except for narrow slot-like sound openings arranged in said plate and the other end of the collar being substantially completely open;
- and
- the slot-like openings being die cast in the plate and the specific dimensions being chosen to establish a desired air friction resistance of the Helmholtz resonator means to achieve a desired attenuation response.
A method for producing an electro-acoustic transducer, comprising the steps of:
- providing a transducer plate arranged in a housing and by which a space in the housing is divided into a front chamber and a rear chamber;
- providing a cover which closes off the front chamber;
- providing a carrier plate in the rear chamber above which the transducer plate is supported;
- providing at least one Helmholtz absorption resonator means provided in the rear chamber for attenuating rises in resonance, said Helmholtz resonator means being formed by a plurality of slot-like openings in said carrier plate and a collar projecting rearwardly of the carrier plate with an end of the collar below the slots substantially completely open;
- and
- selecting a desired air friction resistance of the Helmholtz chamber by die-casting the slot-like openings in the carrier plate so as to set desired specific dimensions to achieve a desired attenuation response of the Helmholtz chamber.
Dependencies are inferred from the claim text.