Visteon Global Technolgoies, Inc.

Douglas Hughson

Charles Francis Weber

Ronald Paul Russ

Paul Douglas Schryer

Stephen Betts

The present invention comprises a method and apparatus for driving and homing a stepper motor. In a preferred embodiment, 24 micro step pulse width modulated (PWM) voltage signals are used to drive the coils of the stepper motor. The phases between the driving signals are 90&#xb0; out of phase. Thus, a sine/cosine methodology is used to drive the motor. Using micro-programmable pulse width modulation (PWM) levels involves the microprocessor reading stored voltage levels from a table stored in memory which corresponds to the amount of angular displacement desired by the motor. These voltage levels are then applied to the motor's coils. The microprocessor performs these operations by executing software instructions stored in memory. The software can be stored in memory located in the controller or in a separate logic block or logic chip. The magnitude of the bounce of a pointer attached to the output shaft of the motor and the magnitude of the noise generated as the pointer contacts a mechanical stop, are both directly related to the applied voltage and speed or frequency of the homing strategy. To reduce the bounce of the pointer and the generated noise to barely discernable levels, the applied voltage is reduced to between 15% and 30% of the normal driving voltage (approximately 1 volt for a 5 volt system). Additionally, the speed of homing is set to a value below the new start-stop frequency of the motor.

Re-zeroing of a stepper motor without noise or movement

An electrical connector,for drop-in connection of an electronic module,(such as an audio speaker assembly) having at least two lead wires,, to a flex circuit,having a like number of circuit traces,arranged on a mounting surface,, comprising: (1) an electrically insulative body,having generally opposed first and second major surfaces,; and (2) at least two electrically conductive, generally elongate biasing members,disposed within the body, each biasing member having first and second ends,and a contact region,proximate the second end, wherein each first end,is exposed through the first major surface,and is adapted for attachment to one of the lead wires,, and wherein each contact region,extends outward from the second major surface,such that each contact region may be resiliently deflected inward toward the second major surface.

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White Lake, MI, United States of America

Douglas Hughson