PURPOSE: To make sure of safety by securing a driving function in the irreducible minimum of necessity in a way of being selected to control over a limp home circuit at the time of something wrong with the system, while interrupting a fuel supply to an engine forcibly at a time when engine speed has exceeded the specified value.
CONSTITUTION: A sleeve target position signal outputted out of a central processing unit 1 is inputted into a servo circuit 3 which emits a duty specific signal of a governor driving pulse. In addition, this central processing unit 1 is provided with a built-in watch dog timer 5 or external watch dog 7 for detecting this operating malfunction, and a reset signal outputted from these elements is inputted into a switch select circuit 9. In this case, the duty specific signal outputted out of an analog limp home circuit 13 and a fuel-cut signal are inputted into two select switches 15 and 17. In succession, the signal selected by these switches 15, 17 is inputted into an overrun-proof circuit 19, thereby outputting each driving pulse of a governor and a fuel-cut valve.
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KITANO YUICHI
KURIHARA KAZUMASA
SHINAGAWA MASAHIKO