| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device capable of detecting, with high accuracy, the presence or absence of disconnection of a speaker circuit without adding a complicated circuit configuration. <P>SOLUTION: A speaker circuit disconnection detecting device is a disconnection detecting device for a speaker circuit made up of a connection cable and a speaker connected to the connection cable. The speaker circuit disconnection detecting device comprises: AC signal applying means for applying an AC signal to the speaker circuit via a resistor having an impedance sufficiently greater than an impedance of the speaker circuit; and disconnection detecting means for detecting an inter-terminal voltage in the speaker circuit to which the AC signal has been applied by the AC signal applying means so as to compare the inter-terminal voltage with a predetermined voltage, thereby detecting that the speaker circuit is in an abnormal state if the inter-terminal voltage is equal to or greater than the predetermined voltage and that the speaker circuit is in a normal state if the inter-terminal voltage is lower than the predetermined voltage. <P>COPYRIGHT: (C)2013,JPO&INPIT |
