| 摘要 |
PROBLEM TO BE SOLVED: To enable even an in-vehicle electronic apparatus with a low-performance microcomputer installed therein to perform sound volume control by utilizing vehicle speed pulses from a vehicle speed sensor. SOLUTION: A signal processing circuit 16 of an in-vehicle electronic apparatus 10 amplifies an input audio signal SIN to generate an output audio signal, generates a vehicle speed voltage signal having a voltage corresponding to a vehicle speed of a vehicle on the basis of a vehicle speed pulse signal SP from a vehicle speed sensor 15, and changes a voltage level of an output audio signal SOUT outputted by an amplifier circuit on the basis of a difference between the voltage of the vehicle speed voltage signal and a voltage of the output audio signal SOUT. COPYRIGHT: (C)2011,JPO&INPIT
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