PURPOSE: To save a number of terminals, in a Diesel engine, by outputting a continuous square wave signal, in which duty ratio is changed by an arithmetic result of an injection quantity target value, converting the signal into a voltage signal and inputting said signal to an actuator control circuit.
CONSTITUTION: A digital signal of a speed detector unit 81, accelerator signal, intake pressure signal, intake temperature signal and fuel temperature signal are A/D converted and input to an MCU80, to calculate an injection quantity target value, and a continuous square wave signal, controlled with duty ratio, is output from a terminal 85. This output is input to a filter circuit 87 via an output buffer 86. This filter circuit converts the square wave signal into a voltage signal Vs to an electromagnetic actuator servo circuit in a secondary low-pass filter circuit constituted by an operational amplifier 871 and the like. In this way, only one output terminal is required for the target value signal, and the saved terminal can be used for the other purpose.
OGISO HARUHIKO
HASEGAWA TAKASHI
HAYAKAWA TAKASUKE
| JPS52151424A | 1977-12-15 |