| 摘要 |
PURPOSE:To prevent shut off of a load drive pulse signal because of surge noise by a method wherein when an average value of load currents is abnormal, through alternate repetition of a duty ratio command value and a duty ratio lower than the command value, a load is driven. CONSTITUTION:A car speed signal (a) is inputted to a microcomputer 11. A start signal (d) and a duty ratio signal (b) are inputted from the microcomputer 11 to a PWM generator 12, and from the PWM generator 12, a PWM completion signal (c) and a drive signal (h) are outputted to the microcomputer 11 and a transistor 5. A load current signal (i) from a solenoid 6 and a start signal (g) from the microcomputer 11 are inputted to an A/D converter 13. Meanwhile, an A/D conversion result signal (e) and an A/D completion signal (f) are outputted from the A/D converter 13 to the microcomputer 11. When an average value of load currents is abnormal, through alternate repetition of a duty ratio command value and a duty ratio lower than the command value, a load is driven. |
