| 摘要 |
<p>[Problem] To provide a vehicle proximity notification device that is capable of rapid detection even if a supply fault, ground fault or other fault occurs in a speaker service wire, and that uses a digital BTL amplifier that is capable of self-protection. [Solution] A vehicle proximity notification device is provided with: a synthetic sound source that synthesizes a sound signal and generates a vehicle proximity notification sound signal; and a BTL amplifier that converts the vehicle proximity notification sound signal generated by the synthetic sound source to a PWM pulse, drives a semiconductor switch and amplifies the vehicle proximity notification sound signal. Said vehicle proximity notification device outputs the vehicle proximity notification sound signal to a speaker connected to an output terminal of the BTL amplifier, and is provided with: a lowpass filter by which the BTL amplifier's output voltage waveform is acquired and filtered; and a fault assessment section by which the voltage waveform filtered by the lowpass filter is compared to a reference voltage generated by dividing the BTL amplifier's power supply voltage, and a fault in the BTL amplifier or in a load connected to the BTL amplifier output is assessed.</p> |
