| 摘要 |
PURPOSE:To prevent destruction of a speaker when abnormality occurs in a power amplifier by shortcircuiting the connecting point of an overcurrent protective circuit between output of a power amplifier and a speaker and the ground by output of a detecting circuit that detects abnormality of a power amplifier. CONSTITUTION:When abnormality such as generation of DC current occurs in a power amplifier, this is detected by a detecting circuit 3 to operate a shortcircuiting circuit 4. At this time, since DC current is generated in the power amplifier, large amount of current flows in an overcurrent protective circuit 2 to operate the overcurrent protective circuit 2 and to separate the power amplifier 1 and a speaker SP. |
