Abstract: A vehicle proximity annunciator device reduces an occurrence of a pop noise without an additional circuit changing an output of a power amplifier. A capacitor is located between a connection point connecting multiple resistances generating a reference voltage and a ground terminal. The capacitor causes a rise-up time of the reference voltage to delay at a start of power supply to a power source terminal. A sound emission signal is increased at substantially a same level of the reference voltage so that a variation of a differential voltage between the reference voltage and the sound emission signal falls in a pre-determined range.

Abstract: A vehicle proximity annunciator device reduces an occurrence of a pop noise without an additional circuit changing an output of a power amplifier. A capacitor is located between a connection point connecting multiple resistances generating a reference voltage and a ground terminal. The capacitor causes a rise-up time of the reference voltage to delay at a start of power supply to a power source terminal. A sound emission signal is increased at substantially a same level of the reference voltage so that a variation of a differential voltage between the reference voltage and the sound emission signal falls in a pre-determined range.

Abstract: A load driving semiconductor apparatus includes: a driving transistor, which operates based on an input voltage from an external circuit; a power semiconductor device controlling power supply to a load in such a manner that the power semiconductor device supplies electric power to the load when the transistor operates, and the power semiconductor device stops supplying electric power to the load when the transistor stops operating; and a mounting board, on which the driving transistor and the power semiconductor device are mounted. The mounting board includes a heat radiation pattern for emitting heat generated in the power semiconductor device. The heat radiation pattern includes a heat receiving pattern, on which the driving transistor is mounted.

Abstract: A load driving semiconductor apparatus includes: a driving transistor, which operates based on an input voltage from an external circuit; a power semiconductor device controlling power supply to a load in such a manner that the power semiconductor device supplies electric power to the load when the transistor operates, and the power semiconductor device stops supplying electric power to the load when the transistor stops operating; and a mounting board, on which the driving transistor and the power semiconductor device are mounted. The mounting board includes a heat radiation pattern for emitting heat generated in the power semiconductor device. The heat radiation pattern includes a heat receiving pattern, on which the driving transistor is mounted.