| 摘要 |
PURPOSE:To readily detect the disconnection of a coil and the shortcircuit by discriminating the output of a comparator for comparing a voltage of a connecting point of the coil with a switching element with a reference voltage immediately after the switching element is interrupted. CONSTITUTION:A processor 100 applies a signal of high level to the base of a transistor 6 during a period W to energize a coil 5. Immediately after the transistor 6 is interrupted, i.e., at a time t2, the voltage of a connecting point 7 of the coil 5 with the transistor 6 becomes a high level by the forward voltage V1 of a diode D from a power source voltage VB. A comparator 10 outputs a signal of low level when the voltage of the point 7 is smaller than the reference level signal from a reference level setter 12. Thus, the disconnection of the coil 5 is detected. |
