| 摘要 |
PURPOSE:To exactly break an electromagnetic valve by providing a control signal generating circuit, a control signal balancing circuit, two comparators to compare the output of the balancing circuit with a set level, and to generate outputs, and an electromagnetic valve closing circuit to respond to the output of the comparators. CONSTITUTION:Valve make and break control signal from a control signal generating circuit 4 with respect to the presence or absence of square wave signal output is averaged in an integrating circuit 5, and when the output value of the circuit 5 is between the different threshold values of the comparators 6A and 6B, output is generated from a logical operation circuit 7 by means of the output of the comparators 6A and 6B, and then the output leads the circuit 8 to open the fuel electromagntic valve 9. And, in case where the circuit 4 generates a repeated square wave signal, the output value of the circuit 5 becomes a middle value between the different threshold values of the comparators 6A and 6B and the electromagnetic valve 9 turns to be opened. In case where the output of the circuit 4 is fixed, the output value of the circuit 5 becomes an outside value of the different threshold values of the comparators 6A and 6B and the electromagnetic valve 9 turns to be closed. The threshold values of the comparators 6A and 6B are set up so as to make such operations possible. |
