Did You Know...
...that power steering was invented by independent inventor Francis W. Davis? As chief engineer in the 1920s of the truck division of the Pierce Arrow Motor Car Company, he saw how hard it was to steer heavy vehicles. So that he would be able to keep the profits from his future invention, Davis left his job, rented a small engineering shop in Waltham, Mass., and developed a hydraulic power steering system that led to power steering.
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| Number | Title | Issue Date |
| 7268507 | Motor controller A DC power supply, a DC motor driven by DC voltage outputted from the DC power supply, and a control unit outputting a drive control signal to drive the DC motor are provided. A motor drive switch is provided between the DC power supply and the DC motor, and a brake... | 09/11/2007 |
| 7218071 | Method and apparatus for increasing AC motor torque output at low frequency Methods and apparatus are provided for controlling AC motor torque output. The method comprises the steps of producing a current based on a first comparison of a fundamental output frequency of the AC motor with a predetermined frequency and a second comparison of a... | 05/15/2007 |
| 7215093 | Motor drive circuit and motor drive method that can positively perform a brake operation A motor drive circuit includes a first transistor. The collector of a second transistor is connected to the emitter of the first transistor in series. A motor is connected to a connection point between the first and second transistors. A first brake control circuit ... | 05/08/2007 |
| 7153175 | Outboard motor shift control system In an outboard motor shift control system having a shift mechanism including a forward gear, a reverse gear and a clutch and an electric motor moving the clutch to engage with one of the forward and reverse gears or to disengage it therefrom, current supplied to the... | 12/26/2006 |
| 7078876 | Feedforward controller for synchronous reluctance machines The present invention provides an electromechanical energy exchange system with a variable speed synchronous reluctance motor-generator having an all-metal rotor. A bi-directional AC-to-DC electric power converter interconnects the motor-generator with a DC bus. Fir... | 07/18/2006 |
| 6935611 | Motor control device for flow control device A motor control device for a flow control device includes an opening part through which an upstream side of a fluid flow passage is in communication with a downstream side of the fluid flow passage, a valve element that controls a flow of a fluid which passes throug... | 08/30/2005 |
| 6919705 | Drive system A drive system, includes a motor having a neutral terminal, a converter, which has a voltage intermediate circuit and is electrically connected to the motor, a switching device, and a holding brake, which is mechanically connected to the motor. The holding brake has... | 07/19/2005 |
| 6867561 | Electrical machine An electrical machine comprises a rotor without windings, a stator having an armature winding 24, 25 and a field winding 10 for generating a magnetomotive force in a direction extending transversely of the magnetomotive force generated by the armature ... | 03/15/2005 |
| 6788021 | Control method for switched reluctance motor A control algorithm provides automatic control of the turn-on angle used to excite the switched-reluctance motor (SRM). The control algorithm determines the turn-on angle that supports the most efficient operation of the motor drive system, and consists of two piece... | 09/07/2004 |
| 6741050 | Method of controlling and switching for braking an electronically commutated electrical motor A control method and a switching circuit for braking an electronically commutated electrical motor, wherein operation is in a phase period (T) of an inverter relative to at lest one winding, sequentially, both in a motoring mode and a generating operating mode using... | 05/25/2004 |
| 6566839 | Switched capacitor motor driver The present invention is a method and apparatus that allows the torque of an electric motor to be increased allowing the motor to be operated at higher speeds and at higher torque without raising the supply voltage, thus allowing for a wider dynamic range... | 05/20/2003 |
| 6456032 | Method for controlling a motor roller A motor driver for drive-controlling a brushless motor being provided with a delay circuit that detects the motor pulse. When a stop signal is inputted, a transistor is activated, which in turn activates an electric brake to brake the brushless motor, whi... | 09/24/2002 |
| 5828195 | Method and apparatus for electronic braking of an electric motor having no permanent magnets Apparatus for braking either a linear or rotary electric motor having no permanent magnets comprising at least one position sensor for outputting an electrical characteristic representative of motor position and an electronic circuit for generating a puls... | 10/27/1998 |
| 5793168 | Active deceleration circuit for a brushless DC motor A circuit for driving a brushless dc motor includes an active deceleration circuit for rapidly slowing the motor. A phase locked loop senses a position of the rotor for commutating from a drive state to a next drive state in a sequence of drive states at ... | 08/11/1998 |
| 5734241 | Brake control system of a motor A brushless motor includes a stationary member; a rotating member rotatably supported with respect to the stationary member; a stator provided in the stationary member and provided with a stator coil for generating current magnetic field under an exciting... | 03/31/1998 |
| 5315226 | Method for controlling a synchronous motor for implementation of an exact start/stop positioning operation in a recording apparatus A method and apparatus for controlling a synchronous motor with an AC voltage. A rated value proportional to a desired frequency of the AC voltage and related to a rotational speed of the synchronous motor is provided. The rated value is continuously adde... | 05/24/1994 |
| 4827204 | Synchronous motor with dynamic damping In an electric motor with a damping device incorporating a disc-shaped damping mass which is freely rotatable and axially movable in relation to the driven element and consists at least partially of a mangetizable material, the damping mass is located wit... | 05/02/1989 |
| 4492910 | Control circuit for a timing motor In a method and apparatus for regulating the rotational speed of a motor having a rotor with magnetic poles and a stator with at least two coils, wherein during a first operational mode the sinusoidal voltage included in a first of the coils is digitized ... | 01/08/1985 |
| 4492903 | Optimum efficiency brushless DC motor A machine includes a rotor with a magnetic field produced therein that is fixedly oriented with respect to the rotor. The rotor is rotatably mounted within a stator which has a plurality of windings. Means are provided for applying voltage pulses to the s... | 01/08/1985 |
| 4486697 | Reversing device for a two-pole single-phase synchronous motor A reversing device for a two-pole single-phase synchronous motor (3) without a starting coil. The motor comprises a diametrically magnetized permanent-magnet rotor having a shaft that runs against elastic stops for reversing the direction of rotation, and... | 12/04/1984 |
| 4441062 | Missing pulse detector for a synchronous motor drive A missing pulse detector circuit is disclosed which includes a variable frequency VCO and a digital phase comparator. The phase comparator compares the phase of the VCO reference and the phase of a driving signal that drives a synchronous motor drive pack... | 04/03/1984 |
| 4262241 | Control system for commutatorless motor driven through frequency converter A control system for a commutatorless motor comprises a frequency converter which includes two graetz-connected thyristor converters and D.C. lines interconnecting the converters, between an A.C. motor and an A.C. power supply. Motoring operation and rege... | 04/14/1981 |
| 4238717 | Optimum efficiency rotary machine having synchronous operation at a selectable speed A machine includes a rotor with a magnetic field produced therein that is fixedly oriented with respect to the rotor. The rotor is rotatably mounted within a stator which has a plurality of windings. Means are provided for applying voltage pulses to the s... | 12/09/1980 |
| 4110670 | Braking apparatus A brake apparatus is disclosed in which a rotary shaft coupled to a load to be rotated is rotatably supported by a plain bearing and a biasing device is located near the shaft to bias or move the shaft to the biasing device to applying braking force to th... | 08/29/1978 |
| 4088938 | Electronic apparatus for positioning and using AC motors A solid-state valve actuator control system using three-phase AC motors as prime movers having a summing point with a set point input, a position feedback input and a velocity feedback input. Velocity feedback being produced by differentiating position fe... | 05/09/1978 |
| 4085355 | Variable-speed regenerative brushless electric motor and controller system A synchronous polyphase motor is driven and regeneratively braked by relatively high-frequency power switching circuits that cause stator currents to vary sinusoidally with rotor position so the resultant magnetic field of the stator rotates with the roto... | 04/18/1978 |
| 4084120 | Stepper motor valve actuator control apparatus An actuator control system includes a ballscrew type actuator for controlling the positioning of a valve device. A control circuit is responsive to pulsed drive signals for driving a synchronous stepper motor which is operatively coupled to the actuator. ... | 04/11/1978 |
| 4070604 | Stepper motor valve actuator An actuator control system includes a ballscrew type actuator for controlling the positioning of a valve device. A control circuit is responsive to pulsed drive signals for driving a synchronous stepper motor which is operatively coupled to the actuator. ... | 01/24/1978 |
