| 摘要 |
The device includes a housing containing a dc battery, a microphone, an audio tone signal source, and a speaker and headphone jack which can receive audio signals from either the microphone or the tone signal source, and two multi-pin XLR receptacles or jacks, one of which is male and the other of which is female. The connectors can supply audio signals from the microphone or tone signal source to the input of the speaker and headphone jack, or alternatively, such signals can be outputted by the male connector to a circuit external of the housing, or a source external to the housing can be utilized to supply audio signals via the male or female connector to the speaker. Power from the battery is supplied selectively either to the microphone or to the tone signal source by a switch which can be moved to either of two different operative positions, or by a volume control knob which applies power to the speaker circuits. A headphone plug can be inserted into the headphone jack to supply audio signals to a set of headphones rather than to the speaker.
|
