| 摘要 |
PROBLEM TO BE SOLVED: To provide a passive type low-pass filter that can reduce decrease in functions even if a burnout fault occurs in a resistor. SOLUTION: When a burnout fault occurs in one of resistors R2a and R2b for composing a low-pass filter 88, the cut-off frequency of the low-pass filter 88 becomes double the cut-off frequency (f) when each of the resistors R2a and R2b is not disconnected. However, when the cut-off frequency (f) is set to a frequency that is sufficiently low to the frequency band of an electromagnetic interference wave, noise that is superimposed to a torque signal T2 by the electromagnetic interference wave can be reliably attenuated even if the cut-off frequency of the low-pass filter 88 doubles, and immunity required for preventing the generation of the malfunction of an ECU 24 (a microcomputer 60 and a differential amplification circuit 94) due to the noise can be obtained. COPYRIGHT: (C)2003,JPO |
