Actuator Magnetic Gap Adjustment in Wire Matrix Print Heads
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
A technique is described whereby the magnetic gaps in ballistic-type actuators, as used in wire matrix print heads, are adjusted using a current/time-based orientation rather than a measurement of distance. A simple modified drive pulse is used to provide accurate measurements, thereby increasing the efficiency of the magnetic actuator. In prior art, actuators were adjusted by setting the static stroke of the lever arm of the actuator. Variations due to friction, pole face alignment, arm inertia and material properties caused significant differences in operational performance. The technique described herein utilizes a time-oriented adjustment which measures the "Seal Time" value of the actuator. The "Seal Time" is the amount of time required to close the armature from a rest position utilizing a specified drive current pulse.