Electric current control unit, electric current control manner and electromotive type power-steering device

摘要

PURPOSE:To improve responsiveness in a motor driven power steering by comparing a serrate carrier signal with a current detecting voltage value to obtain a second PWM signal and synchronously detecting a motor current. CONSTITUTION:A first PWM generating circuit 16 compares a voltage command value from a circuit 14 with a serrate carrier signal and turns on/off a control PWM signal P1, and a PWM switchover circuit 17 controls a motor 9 in accordance with a right/left switchover signal from a current command circuit 12. Also, a second PWM generating circuit 20 compares a current detecting voltage value below the voltage command value according to a proportion circuit 19 with the serrate carrier signal and turns on/off a second PWM signal, to feedback signals from current detecting terminals 11c, 11d to a signal from the current command circuit 12 via a current detection switchover circuit 18, a sample hold circuit 21, and an A/D converter 22. Thereby, a current instant value which is nearly conformed to an average value is detected from among pulsating currents to increase the responsiveness of a current control system.