Quotables
"Rail travel at high speeds is not possible because passengers, unable to breathe, would die of asphyxia."
Dionysius Lardner, Professor of Natural Philosophy and Astronomy at University College, London ; 1830
PatentStorm News
Make the Most of Our Site
See this month's Top Inventors and Most Cited Patents.
Stay on top of the latest innovations by subscribing to an RSS feed.
Registered users: Manage your profile.
| Number | Title | Issue Date |
| 7372228 | Electric power tool with memory capability The invention relates to an electric power tool having a control and/or regulating device for an electric motor. It is provided that the control and/or regulating device (4) is assigned an electronic memory element (5) for at least one operating state ... | 05/13/2008 |
| 7205737 | Systems and methods of monitoring a motor load Systems and methods of detecting an overload condition. In one embodiment, a method of monitoring a load of a DC motor includes intermittently de-energizing the motor; monitoring a first voltage; and measuring a first interval of time between a starting time and an ... | 04/17/2007 |
| 7088066 | Automatic output power limiting electrical device An eletrical device derives power from an incoming power source to produce output plower to drive the device. The device includes circuitry that determines at lehst one characteristic of the incoming power source, and adjusts the output power used to drive the devic... | 08/08/2006 |
| 6998812 | Method for determining the mass moment of inertia of an electric motor drive system A method for determining the mass moment of inertia of an electric motor drive system of a machine, having a drive motor and further drive elements arranged downstream of the drive motor. The method includes a) determining a compensation current, which compensates l... | 02/14/2006 |
| 6859001 | Torque ripple and noise reduction by avoiding mechanical resonance for a brushless DC machine A method of reducing torque ripple and noise for an brushless DC machine comprising: determining a control frequency for the electric machine, the control frequency indicative of an existing current command to and a rotational velocity of the electric machine; multi... | 02/22/2005 |
| 6836614 | Electrical power tool having a motor control circuit for providing control over the torque output of the power tool A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck. The control circuit for the power tool is operable in a ratcheting or pulse mode that causes the output spindle to ro... | 12/28/2004 |
| 6678594 | User-configurable steering control for steer-by-wire systems A steer-by-wire control system comprising a master control system, a road wheel system, and a hand wheel system is disclosed. The road wheel system is connected to the master control system and includes a road wheel position sensor and a rack force sensor... | 01/13/2004 |
| 6577089 | Pressure control system using input current sensing A method and apparatus for controlling the output function of a permanent magnet brushless DC motor (20), by sensing an input current to the motor (20), by computing an output torque generated by the motor (20) as a function of the input current to the mo... | 06/10/2003 |
| 6504338 | Constant CFM control algorithm for an air moving system utilizing a centrifugal blower driven by an induction motor A method and apparatus for achieving constant air flow rate economically utilizes an induction blower motor with control settings determining the motor excitation voltage. A memory stores, for a variety of motor speeds, a graph of the speeds plotted again... | 01/07/2003 |
| 6441579 | Current magnitude variation correction for open loop stepper motor driver circuit An available input of to a motor controller is used to measure the motor power supply voltage. Typically, a scaled down version of the voltage is sensed. The microprocessor is used to calculate the motor control current, in that case, is then calculated f... | 08/27/2002 |
| 6424799 | Electrical power tool having a motor control circuit for providing control over the torque output of the power tool A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck and has associated therewith a degree of looseness which must be taken up before torque from the motor is a... | 07/23/2002 |
| 6373218 | Electric hand with torque limiter In an electric hand, a cam member 12 mounted to a drive shaft 3a of an electric motor 3 is provided with a pair of cam grooves 15 and 15, a pair of jaw members 2 and 2 for grasping a workpiece are provided with drive pins 13 fitted to the cam grooves 15 a... | 04/16/2002 |
| 6041163 | Apparatus for controlling a pump motor of a forklift truck A pump motor control apparatus is adapted to control a pump motor of a forklift truck by using a driving transistor connected between a battery and the pump motor. The pump motor control apparatus includes a current detection circuit for detecting a curre... | 03/21/2000 |
| 5894206 | Electric power steering apparatus An electric power steering apparatus includes a control unit for controlling a motor drive circuit which drives an electric motor on the basis of a steering torque signal supplied from a steering torque sensor. The control unit includes a center value com... | 04/13/1999 |
| 5838132 | Stepper-motor control method A device for outputting a suitable rotation torque relative to a load torque or actual torque exerted on a stepper-motor when the stepper-motor is used as a drive of an image processing device. The output torque of the stepper-motor depends on a supply cu... | 11/17/1998 |
| 5736823 | Constant air flow control apparatus and method Air handling apparatus (10) delivers a volume of air at a generally constant flow rate regardless of changes in the operating conditions of a system with which the apparatus is used. A blower (12) pushes air from one point to another. The blower is operat... | 04/07/1998 |
| 5731673 | Electrical power tool having a motor control circuit for increasing the effective torque output of the power tool A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck and has associated therewith a degree of looseness which must be taken up before torque from the motor is a... | 03/24/1998 |
| 5689159 | Surgical tool system with brushless, sensorless motor A powered medical instrument includes a manually operable foot switch coupled to a motor control unit which in turn is coupled to an autoclavable handpiece containing a brushless sensorless electric motor driving a tool. The motor control arrangement incl... | 11/18/1997 |
| 5533166 | Method for calculating speed estimated value in speed control system A method for calculating a speed estimated value in a speed control system, comprises the steps of: (a) storing the number of speed detection pulses obtained at each interval of a speed control process and time that the speed detection pulse was obtained;... | 07/02/1996 |
| 5521481 | Speed estimation observer applied to speed control system for motor A speed estimation observer for a motor control system outputs a motor speed estimate in a motor speed control system upon receiving a torque command and an averaged motor speed value. The speed estimation observer includes a time lag correction value cal... | 05/28/1996 |
| 5475289 | Method and apparatus for controlling an electric assist steering system using two-dimensional interpolation for current commands A control arrangement for an electric assist steering system having a variable reluctance motor (26) includes sensing (54) motor position and sensing (110) applied steering torque. A controller determines a desired motor torque assist value in response to... | 12/12/1995 |
| 5469215 | Method and apparatus for controlling an electric motor with compensation or torque ripple An electric motor control system compensates torque ripples to control the rotation of an electric motor more accurately. Compensated current amplitudes corresponding to the torques, speeds and rotational positions in the electric motor are stored in a me... | 11/21/1995 |
| 5461694 | DC motor and controlling system therefor A dc motor wherein a driving force thereof can be used effectively with a simple and compact mechanical construction and a motor controlling system which can control such a dc motor to be driven efficiently. The motor comprises at least two coils, and cha... | 10/24/1995 |
| 5440215 | Electrical power tool having a motor control circuit for increasing the effective torque output of the power tool A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck and has associated therewith a degree of looseness which must be taken up before torque from the motor is a... | 08/08/1995 |
| 5414792 | Electric throttle and motor control circuitry A solid state, electric motor control circuit is provided in conjunction with a solid state throttle and vehicle sensor circuit that together incorporate; a Hall Effect throttle position sensor circuit, a throttle position signal amplifier circuit, a vehi... | 05/09/1995 |
| 5410229 | Motor speed control circuit with electronic clutch The pulse width modulated DC motor speed control circuit indirectly senses motor current using sense MOSFETs and a peak detector circuit with storage capacitor for deriving an average motor current signal. The average motor current signal is used both in ... | 04/25/1995 |
| 5410228 | Method and apparatus for suppressing torsional vibration in an electric motor speed control system Herein disclosed are a method and an apparatus for suppressing a torsional vibration in an electric motor speed control system including a mechanism for transmitting a drive torque from an electric motor to a load through a drive shaft having a torsional ... | 04/25/1995 |
| 5404418 | Closed-loop feedback control system having an adaptive filter A closed-loop feedback control system is disclosed for controlling an operation of a load. An actual operation signal is subtracted from a reference operation signal to produce a resultant signal which is used to control the operation of the load. A filte... | 04/04/1995 |
| 5388176 | DC motor speed control system A speed controller for a DC motor minimizes speed droop and load droop through pulse width or frequency modulation. The controller provides an extra power increase upon engine starting or whenever a heavier load is temporarily encountered. The control cir... | 02/07/1995 |
| 5377296 | Mine winder or hoist drum electric motor control for preventing excitation of oscillation The invention provides a control system for an electric motor arranged to drive a rope drum of a mine winder or a hoist system which includes a conveyance supported by a rope and which forms an oscillating system. The control system includes load sensor w... | 12/27/1994 |
| 5341454 | DC motor control in electronic sewing machine A load of an electronic sewing machine is self-diagonosed by a control system to cause a DC motor to be operated under control to drive upper and lower shafts of the sewing machine. The control system includes an evaluating device to which a voltage value... | 08/23/1994 |
| 5325460 | System and method for controlling the speed of an electric motor in an extremely low speed range using a rotary pulse encoder A system and method for controlling the speed of a motor operating in an extremely low speed range and having a rotary pulse encoder which outputs a pulse whenever a rotation axle of the motor has rotated through a predetermined angle. The extremely low s... | 06/28/1994 |
| 5313988 | Method and device for driving a weaving machine during slow motion A method for driving a weaving machine during slow motion includes the steps of carrying out the slow motion drive using the main drive motor, and controlling excitation of the main drive motor as a function of the load on the weaving machine parts which ... | 05/24/1994 |
| 5294872 | Method and apparatus for operating vacuum cleaner Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaned su... | 03/15/1994 |
| 5291108 | Method of equalizing the torque on a drive of a pilger rolling mill A method and apparatus for torque equalization on the drive of a rolling stand, having a linear oscillatory movement driven via a crank drive, of a Pilger step-by-step rolling mill, particularly a cold Pilger rolling mill. In order to avoid the inefficien... | 03/01/1994 |
| 5291107 | Circuit for driving reel motor of videotape recorder A load driving circuit causes a driving current to flow through a load, such as a reel motor, an audio load or the like through the collector and emitter of a drive transistor. A load voltage which changes according to changes in the driving current is ob... | 03/01/1994 |
| 5289092 | Apparatus and method for d.c. motor control A control for a d.c. motor having a d.c. thyristor power supply connected to a d.c. motor and a control circuit for selectively varying and controlling the level of the current provided by the thyristor power supply to the motor. The thyristor power suppl... | 02/22/1994 |
| 5263113 | Method and apparatus for controlling the speed of a motor An apparatus is disclosed which controls the speed of a motor driving a load. A speed controller finds the difference between a command speed value of the motor and a detected speed value of the motor and generates a command current value of the motor on ... | 11/16/1993 |
| 5261026 | Controlling apparatus for balanced cargo or work handling system A controlling apparatus for use in a balanced work or cargo handling system which aims at detecting the weight of the work or cargo suspended accurately even if a drift occurs in an acceleration detector due to changes in ambient temperature to thereby en... | 11/09/1993 |
| 5239251 | Brushless doubly-fed motor control system An AC variable speed drive (VSD) system having a brushless doubly-fed motor receives power from an electric power grid at a system frequency of the grid and drives a mechanical load. The motor has a rotor with rotor windings and a stator with stator windi... | 08/24/1993 |
