| 摘要 |
<p>Apparatus for determining whether an electromagnetic valve is operating properly wherein an armature of the valve carries an annular magnet facing a Hall-effect sensor switch which is exposed to the magnetic field of the magnet when the armature is in a home position. If the armature is not shifted from its home position when the valve is energized, this malfunction of the valve is detected by an evaluation unit connected in series to the output of the Hall-effect sensor switch. Below the Hall-effect sensor switch a short circuit ring is attached, at a well defined stroke position relative to the magnet, in order to ensure that the magnetic field of the magnet does not influence the working capability of the valve during proper operation. The output of the evaluation unit can be connected to a visual display device.</p> |
