Abstract:
A rotary solenoid comprises: a ferromagnetic core having a rotatable shaft disposed through an axial aperture in the core; a permanently magnetized armature fixedly mounted relative to a first end of the shaft, the armature having a pair of pole portions of opposite magnetic polarity; a first stator pole coupled to the first end of the core and extending proximate the armature; a second stator pole coupled to the second end of the core and extending proximate the armature; and a winding disposed around the core, wherein the rotor rotates from a first position to a second position in response to a direct electrical current in a first direction through the winding, and the rotor rotates from the second position to the first position in response to a direct current in a second direction through the winding. The first and second stator poles may be curved around the outer circumference of armature and spaced apart therefrom. A plate may be fixed relative to one of the rotor and the core and a protrusion fixed relative to the other of the rotor and the core, wherein the protrusion is received within a slot disposed in the plate for defining the angle of rotation between the first and second positions. The rotary solenoid may be used in an image enhancement device such as a night and low-light vision device or a thermal imaging device for driving a shutter between open and closed positions.