Wenderoth, Lind & Ponack, L.L.P.
Device for detecting fault in solenoid valve
 A device for detecting a fault in a solenoid valve prevents a feeding system from supplying a drive current to a solenoid valve coil which actuates the solenoid valve from being damaged at the time of detection of the fault. The feeding system is provided with a first switch installed between one end of the solenoid valve coil and a battery, a second switch installed between the other end of the solenoid valve coil and a ground, and a plurality of wires for connecting the battery, the first and second switches and the solenoid valve coil. A test power supply system is connected to one end or the other end of the solenoid valve coil and supplies a micro test current to the solenoid valve coil when a current from the battery to the solenoid valve coil is cut off. A controller controls an operation of the first and second switches, and detects a fault in the feeding system on the basis of a voltage at the end of the solenoid valve coil opposite the end which the test power supply system is connected in accordance with the operating state. 
Tokico Ltd.
G H
G01R H01F
inventional inventional
Osamu Kazumoto Toshio
Sumiya Sano Takayama