| 摘要 |
PROBLEM TO BE SOLVED: To control a drive voltage of a cooling fan without using any expensive temperature sensor for a video/audio apparatus so as to realize operations optimum to a temperature rise and a noise. SOLUTION: A microcomputer 1 controls an entire television receiver and has current time information. A nonvolatile memory 2 has a table denoting at what voltage a cooling fan corresponding to each time is to be driven. The cooling fan is driven at a voltage of 5 V from 11:00 to 17:00 hours, number of revolutions of the cooling fan is maximized and the noise produced from the cooling fan is maximized. On the contrary, surrounding noises are reduced at night and a noise level of the cooling fan sensed by viewers is lowered. Since the atmospheric temperature is also lowered even when the drive voltage of the cooling fan is decreased to 3 V, the temperature in the inside of the television receiver product remains to be a level having no problem about the reliability and the noise from the cooling fan can also be decreased. Drive voltage information decided by the microcomputer 1 is delivered to a variable voltage regulator, which supplies the information to the cooling fan 4.
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