| 摘要 |
<p>An audio system includes a light sensitive switch connected to a microphone. Activation of the microphone operates the switch, thereby indicating that the microphone is in use. When the user turns the microphone on, a voltage is applied across a light emitting diode which causes the diode to emit light. The light activates the light sensitive switch which is connected to the remainder of the audio system. The system interprets activation of the light sensitive switch as an indication that the microphone is in use and responds accordingly.</p> |
