Abstract: An automobile wheel having a wheel di.sk with improved stiffness and increased strength and driving stability. An imaginary inward angled line is tangential to an inner circumferential surface of an inward recessed circumferential portion of a hat portion and tangential to an inner circumferential surface of a hub surface rounded portion of a hub mounting portion. An imaginary outward angled line is tangential to an inner circumferential surface of an outward recessed circumferential portion of the hat portion and runs through an intersection point of a disk flange and an imaginary bottom line. The imaginary bottom line extends along a back side surface of the hub mounting portion. The imaginary inward and outward angled lines satisfy a ratio of an imaginary outward angle to an imaginary inward angle of equal to or greater than 0.8 to equal to or smaller than 1.25 with respect to the imaginary bottom line.

Abstract: The composing circuit outputs a lower voltage out of voltages output from the constant voltage generation circuit and the dummy pump circuit as a voltage to the sensing circuit. The sensing circuit compares voltages to generate a pump activation signal for activating the pump circuit. Since when an external power supply voltage is a low voltage, the voltage applied to the sensing circuit will be an output voltage of the dummy pump circuit having the same output characteristics as those of the pump circuit in place of the reference voltage, no pump activation signal is generated. As a result, when the external power supply voltage is a low voltage, power consumption can be suppressed without uselessly outputting a pump activation signal.