| 摘要 |
<p>[Problem] To detect the number of audio power amplifiers which are connected using cables for cascade connections. [Solution] An audio power amplifier (2a), which can be cascaded in multiple units to obtain a combined output, has an output transformer (4a). The secondary winding (8a) of the output transformer (4a) has a center tap. When the input terminal (24a) of the audio power amplifier (2a) is connected, by cables (56), to the output terminal (22b) of an audio power amplifier (2b) provided in the subsequent stage, the center taps and one of the ends of each of the secondary windings (8a, 8b) of the output transformers (4a, 4b) of the audio power amplifiers (2a, 2b) are cascaded. The number of the audio power amplifiers connected by the cables is detected and output by a comparator (72a).</p> |
