Abstract: 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° 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.

Abstract: 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° 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.

Abstract: An electrical connector 100 for drop-in connection of an electronic module 50 (such as an audio speaker assembly) having at least two lead wires 52, to a flex circuit 70 having a like number of circuit traces 72 arranged on a mounting surface 60, comprising: (1) an electrically insulative body 10 having generally opposed first and second major surfaces 12/14; and (2) at least two electrically conductive, generally elongate biasing members 20 disposed within the body, each biasing member having first and second ends 22/24 and a contact region 26 proximate the second end, wherein each first end 22 is exposed through the first major surface 12 and is adapted for attachment to one of the lead wires 52, and wherein each contact region 26 extends outward from the second major surface 14 such that each contact region may be resiliently deflected inward toward the second major surface.

Abstract: A method and apparatus is provided for electrically interconnecting a circuit pattern with an adjacent circuit on a substrate. The circuit pattern is positioned in direct physical contact with the adjacent circuit to create a single electrical interface between the circuit pattern and the adjacent circuit. A compliant spring member is supported by the substrate for creating a normal force at the single electrical interface for holding the circuit pattern and adjacent circuit together. The compliant spring member is sufficiently flexible to facilitate electrical interconnection of the circuits along a non-planar substrate. Various embodiments are described.

Abstract: A helical, positive displacement, external gear pump having a gear contact ratio greater than unity wherein the space between two meshing gear teeth registers with the cutoff edge of the outlet port at one end of the space and as it registers with the inlet edge of the inlet port at the opposite end of the space thereby eliminates the need for providing end plate recesses.