| 摘要 |
There is provided a condenser microphone in which even if strong electromagnetic waves are applied from a cellular phone or the like, the balance between a filter circuit for a No. 2 pin on the hot side and a filter circuit for a No. 3 pin on the cold side is maintained. The condenser microphone includes a printed wiring board 200 housed in a microphone casing and a three-pin type output connector, and is configured so that a No. 1 pin of the output connector is connected directly to the microphone casing and is connected to a ground electrode of the printed wiring board 200 via a high-frequency choke coil IL; on the printed wiring board, a first filter circuit 401 connected to the No. 2 pin on the hot side and a second filter circuit 501 connected to the No. 3 pin on the cold side, both filter circuits each including capacitor devices C and inductor devices L, are mounted; and the first and second filter circuits 401 and 501 are disposed so as to be substantially symmetrical with each other with respect to an imaginary centerline X1-X1. In the condenser microphone, the high-frequency choke coil IL is provided in the number of two, and these choke coils IL1 and IL2, together with the first and second filter circuits 401 and 501, are disposed so as to be substantially symmetrical with each other with respect to the imaginary centerline X1-X1. |
