| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a speaker driving circuit having a short-circuit and failure detecting function for detecting abnormality before the speaker driving circuit is actually used, and for preventing a person from perceiving that a detecting operation is being performed, and a detection method of the speaker driving circuit.SOLUTION: A speaker driving circuit having a short-circuit and failure detecting function is a speaker driving circuit 21 including a speaker amplifier part 25 for receiving a voice output, and for outputting a voice to a speaker 22. An input part 30 intermittently supplies a test output having a frequency other than an audible band to the speaker amplifier part 25. A detection part 26 intermittently detects the short-circuit of the speaker 22 and the failure of the speaker driving circuit 21 on the basis of an output signal from the speaker amplifier 25. A determination part 27 receives a signal from the detection part 26, and determines the short-circuit of the speaker 22 and the failure of the speaker driving circuit 21, and instructs a display lamp 29 to blink or light.</p> |
