| 摘要 |
A system performs audio matching to determine the channel to which a television set is tuned. In one embodiment, the system feeds two audio signals to primary and secondary windings of an audio transformer, and employs an output signal taken from a center tap on the primary winding to determine whether the audio signals match. In another embodiment, the system detects transitions of the two audio signals, produces a pulse for each transition, and compares the pulses to determine whether the signals match.
|
