Patent ID: 9106990
Filing Date: 2015-08-11
Classification: H04R

Abstract:
1. A failure detection device for a speaker mounted on a vehicle, the failure detection device comprising: a signal generator configured to generate a sound signal corresponding to a sound outputted from the speaker; an amplifier configured to amplify the sound signal generated by the signal generator; a coupling capacitor configured to supply the sound signal amplified by the amplifier to the speaker; a supply circuit configured to supply a direct-current test current to the speaker in such a manner that the test current does not flow through the coupling capacitor by applying a test voltage to the speaker, the test voltage being higher than a voltage of the sound signal supplied from the coupling capacitor to the speaker; a detection circuit configured to directly or indirectly detect a terminal voltage on a terminal of the speaker; and a determination section configured to determine whether at least one of an open-circuit and a short-circuit occurs in the speaker based on the terminal voltage during application of the voltage of the sound signal to the speaker; wherein: an amplitude of the test current is smaller than an amplitude of the sound signal supplied through the cooling capacitor to the speaker to reduce an influence of the test current on a tone of the sound outputted from the speaker.