Parker-hannifin Corporation

Microvision, Inc.

Scott A Ellerthorpe

Christopher M Botka

Christopher A Wiklof

Gregory T Gibson

Edward M Millet

A portable end device, such as a bar code scanner, may be equipped with auxiliary interfaces. The auxiliary interfaces may be easily added to the end device as a replaceable cover, such as a replaceable battery door. A signal path conducts signals to and from the replaceable cover. One auxiliary interface is a Bluetooth radio. Data integrity protocols may be selected to guarantee delivery and guarantee no duplicate deliveries. Host pairing algorithms may provide standard or strong pairing with a host computer. Ergonomic interface features allow a user to control and monitor the operation of the end device and the data link with minimal hardware cost and battery life impact. Host software programs provide data routing, automatic reestablishment of the data link, and other functions. The system is adaptable to a wide array of use environments through the selection of timer parameters in the end device.

Wireless interface and method for enhanced functionality

Electronic device with auxiliary interfaces

Motor stall can be detected without the use of additional sensors in a hybrid stepper motor through the detection of a harmonic component an associated motor spectrum. The associate motor spectrum can be a motor command voltage spectrum. For example, all of the harmonic components except for the second harmonic are eliminated from the voltage and the presence or lack thereof indicates whether or not the motor has stalled. The harmonic component can be isolated with the use of several cascaded filters. These filters can include notch filters and bandpass filters. Additionally, the circuit may be realized as either an analog, digital or hybrid circuit. The motor may be either hybrid stepper motor having 2, 3, or 5 phases, or a variable reluctance motor.

Sensorless stall detection for motors

An energy absorbing filter for reducing mechanical oscillations in motor is disclosed. The energy absorbing filter places a virtual shunt across the motor windings so as to dissipate mechanical vibrations as resistive losses. This is accomplished by the placing of a large capacitance in parallel with the windings. The impedance of the filter and the windings combined is purely resistive. The motor may be any kind of motor including a 2-, 3-, or 5-phase hybrid step motor. The filter may be realized as an analog or digital filter, or may be a hybrid of the two. Additionally, the filter may be realized through hardware or through software in the form of a computer program.

Growing community of inventors

San Francisco, CA, United States of America

Scott A Ellerthorpe