| 摘要 |
<p>A method of controlling the operation of a solenoid, particularly for operating the fuel delivery valve of a fuel injector of an internal combustion engine. The method comprises controlling the rate of rise of the current in the solenoid (11) winding at a predetermined rate during at least the period between initiation of the current supply (10) and the commencement of movement of the solenoid armature. The said predetermined rate of rise of the current being preferably linear and being independent of the maximum rate attainable at the nominal voltage of the electrical source supplying the current. The rate of rise of the current is monitored (13) and the supply voltage is cyclically varied in response to said monitoring to maintain the predetermined rate of rise of the current. Also the cyclic variations of the current is monitored (22) to detect when the frequency of said cycles substantially change indicating the completion of the full extent of the movement of the solenoid (11) armature.</p> |
