DEVICE FOR DRIVING SOLENOID VALVE FOR ANTI-SKID BRAKE

摘要

PROBLEM TO BE SOLVED: To stabilize the switching response time of a solenoid valve and to prevent deterioration of ABS control performance by holding current passing the solenoid valve at nearly constant value. ;SOLUTION: A calculation circuit 23 disposed in a control unit 22 determines increasing, decreasing or holding the hydraulic pressure in a wheel cylinder based on detection signals of wheel speed sensors 5 to 8 and outputs control signals for realizing these demands to a PWM circuit 24. The PWM circuit 24 compares the voltage of a battery 11 detected via a conductor 26 with a standard triangular wave signal to make the control signal pulsewidth modulate and outputs the pulse signal to a transistor 25, thereby driving the transistor 25 with duty responsive to the variance of the voltage of the battery and holding current passing the solenoid 17 of a solenoid valve at a nearly constant value.;COPYRIGHT: (C)1997,JPO