| 摘要 |
PROBLEM TO BE SOLVED: To provide a multifunction and high performance electronic siren device for vehicle capable of preventing the peripheral residents of vehicle from being troubled by any siren sound from a loudspeaker. SOLUTION: The driving circuit 10 of a loudspeaker 1a which blows a siren sound is provided with a volume control circuit 20 for gradually increasing the volume of the blowing sound, and for maintaining the volume to the maximum value after the lapse of a fixed time so that the peripheral people of a vehicle can be prevented from being surprised at the siren sound. Also, the driving circuit 10 is provided with an error judging circuit 30 for judging an error such as the short circuit of the loudspeaker 1a according to the drop of the voltage, currents, and power supply voltage, and for executing LED display so that the maintenance check can be easily performed, and that the generation of the failure of the siren sound in emergency can be reduced. |
