Patent ID: 9000900
Filing Date: 2015-04-07
Classification: B60Q,H03F,H03G,H04R

Abstract:
1. A vehicle proximity annunciator device for notifying vehicle proximity by emitting an annunciation sound from a speaker equipped in a vehicle, the vehicle proximity annunciator device comprising: a reference voltage generation circuit generating a reference voltage obtained by dividing a power supply voltage, which is applied to a power source terminal, by a plurality of resistances; a sound emission signal generation portion generating a sound emission signal; a power amplifier outputting an amplified signal from an output terminal of the power amplifier, the amplified signal being generated by amplifying a differential voltage between the reference voltage and voltage of the sound emission signal; a coupling capacitor located between the output terminal of the power amplifier and the speaker; and a rise-up delay capacitor located between a connection point connecting the plurality of resistances generating the reference voltage and a ground terminal, wherein the rise-up delay capacitor causes a rise-up time of the reference voltage to delay at a start of power supply to the power source terminal, wherein the sound emission signal generation portion increases the sound emission signal with substantially a same voltage level as the reference voltage so that a variation of the differential voltage between the reference voltage and the voltage of the sound emission signal falls in a threshold range.