Three-position solenoid uses just one spring

A new design by TLX Technologies, Waukesha, Wis. (tlxtech.com), uses only one spring, which expands against a hard stop to center the armature and compresses when the armature moves in either direction. This gives a tighter tolerance on the solenoid's center position and eliminates the need to set up and adjust two springs. The solenoid also uses a shunt ring to increase pull-in force compared to traditional three-position latching solenoids. As a result, the solenoid can be smaller, given the same voltage and current requirements. The solenoid generates from 1 oz to 100 lb of force operating on 3 to 48 Vdc. Operating strokes range from 1 mm to 1 in., response time is less than 8 msec, and operating life is over a million cycles.