| 摘要 |
PURPOSE:To make a relay not to actuate when at least two elements are simultaneously out of order by a structure wherein a check circuit to allow the actuation of the relay to open a fuel supplying solenoid valve. CONSTITUTION:The opening of a solenoid valve 6 is resulted after the sequential operations of the following actions: (1) A capacitor C is charged through a relay R and a diode D1 when a water flow switch S is turned ON. (2) Due to the consequent turning ON of a switching transistor Tr1, the positive side of the capacitor C is connected to the ground (b), resulting in keeping the connection part a2 of the capacitor C and a diode D2 negative with respect to the ground (b). (3) Due to the resultant turning ON of a transistor Tr2, a voltage larger than the operating voltage is applied across the relay R, resulting in actuating the relay R. (4) After the discharging of the capacitor C, the voltage applied across the relay R serves as a supply voltage to keep the actuation of the relay R on. Thus, if the actions described above (1)-(3) fail to be performed sequentially, no action mentioned in (4) is brought into actuation and consequently the solenoid valve 6 does not be open. |
