Control of proportional solenoid with movable element

摘要

The coil (100) of the electromagnet draws current from the DC supply (Ubat) when a transistor switch (110) in series with a current-measuring resistor (120) is turned on by a current regulator (200). A set-point (HS) for the position of the armature is combined (170) with a measure of the actual position (HI) obtd. from a memory (150) contg. the relationship between magnetic flux density and armature position, with the current as parameter. The flux density is measured by a sensor (160) and the current (II) is derived (130) from the emitter voltage drop. A position regulator (190) determines a set-point current for comparison (140).