| US 7,542,578 B2 | ||
| Condenser microphone | ||
| Hiroshi Akino, Machida (Japan) | ||
| Assigned to Kabushiki Kaisha Audio-Technica, Machida-Shi, Tokyo (Japan) | ||
| Filed on May 12, 2005, as Appl. No. 11/127,197. | ||
| Claims priority of application No. 2004-144841 (JP), filed on May 14, 2004. | ||
| Prior Publication US 2005/0254671 A1, Nov. 17, 2005 | ||
| Int. Cl. H04R 3/00 (2006.01) | ||
| U.S. Cl. 381—113 [381/111; 381/120; 381/375] | 2 Claims |
| 1. A condenser microphone, comprising:
a condenser microphone capsule,
a vacuum tube used as an impedance converter, and
an output transformer having a primary winding connected to a plate and a screen grid of the vacuum tube and a secondary winding
connected to a phantom power source via an output connector,
the condenser microphone being operated by the phantom power source,
wherein the primary winding has a center tap and both ends of the secondary winding are connected to the center tap via constant
current diodes, respectively.
|