Title:
AUDIO SIGNAL UNIT
Document Type and Number:
Japanese Patent JP3896810
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an audio signal unit in which the number of I/O ports is decreased.
SOLUTION: The audio signal unit comprises a sound chip 1 and a switching circuit 2. When a user sets a microphone volume, signals S0 and S1 of '1' are outputted from a system CPU and fed to the switching circuit 2 through the sound chip 1. When the signals S0 '1' is fed to the switching circuit 2, a selector 32 is switched and the signal at an I/O port 33 is fed to a microphone input terminal 11 through an amplifier 37. When the signals S1 '1' is fed to the switching circuit 2, power is supplied to the amplifier 37 and an incorporated microphone 36. On the other hand, when the user sets a line input volume, signals S0 and S1 of '0' are outputted from the system CPU. Consequently, the selector 32 outputs the signal at the I/O port 33 to a line input terminal 12 and power supply to the amplifier 37 and the incorporated microphone 36 is turned off.
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Inventors:
Makino Hideo
Application Number:
JP2001201259A
Publication Date:
March 22, 2007
Filing Date:
July 02, 2001
Export Citation:
Assignee:
Yamaha Corporation
International Classes:
H04R3/00; (IPC1-7): H04R3/00
Domestic Patent References:
| JP11069478A | ||||
| JP5236391A |
Attorney, Agent or Firm:
Masatake Shiga
Takashi Watanabe
Takashi Watanabe