| 摘要 |
Apparatus for maintaining uniform volume in television or audio system forms part of television set and contains an eight-bit DSP having a CPU, RAM and ROM memory, an analog digital convertor, a voltmeter and a timer and switch, a "SAVE" button. When the user begins listening to a first channel, the user experiments with the volume desired and once the user has it the user pushes the "SAVE" button on the TV set which activates the voltmeter to measure the volume of the tension on the output of the sound amplifier, and correspondingly the loudness level, at a number of intervals to capture variations occurring during the show. DSP calculates a mean volume of the tension which is then transmitted to the RAM and retained in memory. The DSP switches off the apparatus. When the user subsequently switches to a second channel the apparatus switches on and the voltmeter measures the volume of the tension of the second channel at a number of intervals, the digital signal processor calculates the mean level and once again transmits that mean volume of the tension level to the RAM. The DSP calculates the difference between the mean volume of the tension of the saved tension and that of the second channel. If there is a difference in volumes of the tension level, the DSP sends a signal to the apparatus to adjust the volume of the tension until the difference becomes zero. In preferred embodiment, voltmeter measurement is first done crudely, then precisely.
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