Patent ID: 7466169

Claim:
A signal detecting device for a load driving apparatus that controls a current to an inductive load by intermitting a current by a switching element to drive the load, the signal detecting device comprising: current detecting means that detects the current flowing through the load and produces an analog current voltage signal indicative of the detected current; state amount detecting means that detects a state amount other than the current, which changes as the load is driven, and produces an analog state voltage signal indicative of the detected state amount; an A/D converter circuit that subjects the current voltage signal and the state voltage signal to A/D conversion; and selector means that selects the current voltage signal detected by the current detecting means to be subjected to A/D conversion by the A/D converter circuit in an ON period during which the switching element is ON, and selects the state voltage signal to be subjected to A/D conversion by the A/D converter circuit in an OFF period during which the switching means is OFF.