| 摘要 |
PURPOSE:To obtain performance which is not affected by secular voltage variation and is stable against variation in source voltage by comparing variation in the voltage at the connection point between two magneto-resistance element with variation given a phase difference through a delay element. CONSTITUTION:Variation of a magnetic field during the rotation of a permanent magnet joined with a shaft rotating coaxially with the driving shaft in the transmission of a vehicle is detected as voltage variation at the connection point between a couple of magneto-resistance elements 12 and 13 to detect the rotating speed of the shaft. Then, voltages applied to the elememts 12 and 13 are obtained by stabilizing a battery voltage VBATT' through a resistor 10 and a Zener diode 11. For the purpose, the voltage variation at the connection point 10 between the elements 12 and 13 is divided through resistances 14 and 15 and inputted to the plus-side input terminal of a comparator 19, and also inputted to the minus-side input terminal through the primary delay element consisting of a resistance 16 and a capacitor 18, so that the output of the comparator 19 is used as a detection output. |
