11
Lennart Stridsberg: Brushless DC motors/generators. Stridsberg Innovation, Limbach & Limbach, May 12, 1998: US05751089 (33 worldwide citation)

In a rotational/linear brushless DC motor/generator the rotor/slide has many equally spaced permanent magnet poles of alternating polarity and it has no or few magnetically permeable iron parts. These magnets cover typically slightly more than half the pole pitch in trapezoidal embodiments. The stat ...


12
Kwang Hwa Liu: Speed control of brushless DC motors. Birch Stewart Kolasch & Birch, August 21, 2007: US07259531 (28 worldwide citation)

The speed control apparatus comprises a plurality of Hall sensors, a plurality of switches, a turn-on control circuit, and a gate drive logic. The Hall sensors are configured to detect magnetic rotor sections of a poly-phase brushless DC motor at different positions. The switches apply voltages on a ...


13
David R Smith, Robert Villamil: Linear current source amplifier for brushless DC motor. Kollmorgen Corporation, Morgan & Finnegan, March 16, 1993: US05194786 (27 worldwide citation)

There is provided a linear current source amplifier for brushless DC motors with linear characteristic and low noise at high currents. A servo current loop for comparing a desired current with the actual winding current is provided to produce a global error signal. A plurality of linear current foll ...


14
Walter H Sakmann, Volker Zimmermann: Method and apparatus for the constant speed control of brushless DC motors. International Business Machines Corporation, David D Bahler, J S Gasper, J Jancin Jr, April 30, 1985: US04514667 (26 worldwide citation)

Method and apparatus for the constant speed control of a brushless DC motor, whose pole windings receive a pulsed control voltage between their commutation points, control being a function of the speed characteristics of the motor, and the commutation points being synchronized with the drop times of ...


15
Charles C Austin, Bertram J White: Adaptive commutation delay for multi-pole brushless DC motors. Silicon Systems, Hecker & Harriman, June 7, 1994: US05319289 (24 worldwide citation)

A circuit to provide adaptive commutation delay for multi-pole brushless DC motors. The circuit adjusts the commutation delay as a function of the rotational speed of the motor to maximize motor torque and minimize power consumption. Unlike the prior art, the circuit avoids the need for complex circ ...


16
Robert J Lender: Methods of producing slotless and toothless wound stator. Edo Corporation, Daniel H Steidl, January 14, 1986: US04563808 (24 worldwide citation)

Slotless and toothless wound stators are produced for electrical machines, in particular brushless DC motors, by providing temporary teeth at opposite ends of an iron cylinder with smooth inner wall end-to-end, placing an electrical winding without supporting form against the inner wall and between ...


17
Studer Philip A: Direct current motor with stationary armature and field. March 9, 1971: US3569804 (23 worldwide citation)

This disclosure describes a direct current (DC) motor structure having stationary (immovable) field and armature windings. A rotor formed of a material having high magnetic permeability and having a plurality of salient poles is rotatably mounted adjacent to the field winding so that the field windi ...


18
Rex L Allison III: Sample and hold time stamp for sensing zero crossing of back electromotive force in 3-phase brushless DC motors. IXYS CH, Imperium Patent Works, Darien K Wallace, October 4, 2011: US08030867 (22 worldwide citation)

A microcontroller determines the position of the rotor of a brushless, direct-current motor by determining the time of zero crossing of back electromotive force (EMF) emanating from the non-driven phase winding. The zero crossing point is determined by interpolating voltage differentials that are ti ...


19
Gunter Wrobel: Brushless DC motor with tolerance compensation spring. Papst Motoren and Company, Barnes & Thornburg, April 18, 1989: US04823034 (21 worldwide citation)

Prior art stators of brushless DC motors are securely connected with the bearing support member, and/or with the fastening flange. The printed circuit board with electronic components for commutation is arranged for space reasons between the fastening flange and the stator. This type of construction ...


20
Francesco Carobolante, Karl Schlager, Li Hsin D Lu: Current sensing and control in brushless DC motors. SGS Thomson Microelectronics, Theodore E Galanthay, Lisa K Jorgenson, August 12, 1997: US05656897 (20 worldwide citation)

A motor drive system, and method for operating the same, which includes current mirror load current sensing, is disclosed. Sensed current is used in the well known manner to control the low side drive of the motor. The disclosed motor system operates in a bipolar mode on startup, and in a unipolar m ...