| 摘要 |
PURPOSE:To avoid the limitation of a distance between a speaker to be tested and a discrimination device and to simplify the constitution by discriminating the polarity of a speaker coil with a detection output of a transient voltage generated in the speaker coil when a mechanical shock is exerted to cone paper of a speaker. CONSTITUTION:When the cone paper of a speaker 1 is vibrated, a transient voltage is generated in a speaker coil 2, a positive polarity or a reverse polarity signal is outputted and the signal is inputted to a voltage presence detection section 5 via an amplifier 3 and an absolute value amplifier 4. Then the detected output discriminates the polarity of the speaker coil 2. Thus, the limitation of the distance between the speaker 1 to be tested and the discriminating device is eliminated so as to attain normal discrimination even in the vicinity of a sound source and the polarity discriminating device of the speaker whose constitution is simplified is obtained. |
