| 摘要 |
PURPOSE:To prevent erroneous detection by noise signals and to make the detection of rotating angles sure by detecting the zero cross point at the rise in the waveform of the detection signal of a sensor, outputting a reference position signal and a rotating angle position signal and dividing the voltage of the detection signal in the stage of high speed revolutions. CONSTITUTION:A magnetic rotating angle sensor MPU has a coil 6 for detecting a reference position and a coil 9 for detecting rotating angles. When the detection signal (a) of the coil 6 attains >=50mV, the output signal G1 of a comparator CP1 goes low and when the signal (a) attains 0V, the signal G1 goes high. With the level changing point thereof as a reference position, a CPU performs prescribed processing. With the detection signal (b) of the coil 9, comparison is made similarly in a comparator CP2, and the point where the output signal NE thereof changes from low to high is processed as a rotating angle position. Further, if the CPU discriminates the number of revolutions of, for example, >=1,000rpm, the same applies a control signal CS to a change-over part LVC which changes over the level of the signal (a) to, for example, 1/10. Thus, the malfunction of the CP1 is prevented. |
