| 摘要 |
PURPOSE:To smooth the axial displacement of a plunger by improving an exciting method for the solenoid of an electromagnetic linear actuator optimum for power steering and the like, while restraining a noise due to a plunger vibration and hysteresis due to plunger displacement in an axial direction. CONSTITUTION:When a vehicle is running, analogue voltage corresponding to an output from a vehicle speed sensor 20 is outputted from an F-V converter 30 and error voltage between said analogue voltage and amplified voltage from an amplifier 50 is obtained with a differential amplifier 40. Also, a level shift signal in inverse proportion to said analogue signal is generated from a level shifter 60 and a constant current in proportion to the level shift signal is generated from the voltage-constant current converter 71 of a chopping wave voltage generator 70. And chopping wave voltage is generated from a capacitor 73 according to the charging and the discharging operation of constant current switching circuits 72 and 74 on the basis of said constant current, and the solenoid 12 of a linear actuator is duty controlled, according to a comparison signal from a comparator 80 on the basis of the chopping wave voltage and the aforesaid error voltage.
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