| 摘要 |
PURPOSE:To make a proper tone color settable according to a driving state, by composing plural oscillating signals different oscillatory frequency each with a warning sound signal, while selecting one oscillatory frequency in an oscillation circuit being yet higher than others in a state that exceeds the specified speed. CONSTITUTION:When an alarm switch 14 is operated, each of oscillation circuits 16-19 is driven via an oscillation control circuit 15 and the oscillating signal is composed with a mixing circuit 24 whereby warning sound in a normal tone color is generated out of a sounding body 25 as a warning sound signal. And, at this time, if a car is in driving on a superhighway or the like and the high-speed driving state is detected with a car speed switch circuit 21, a conversion command of oscillatory frequency is given to the fourth oscillation circuit 19 from a frequency control circuit 23, and the oscillatory frequency is selectively set to, for example, a high requency of 2,100Hz. With this constitution, a frequency characteristic of the warning sound signal out of the mixing circuit 24 comes into a state that a frequency component becomes increased, thus such a warning sound as being excellent in directively and suitable for a high-speed driving state is generated. |
