Did You Know...
...that the x-ray was discovered purely by accident? When German physicist Wilhelm Konrad von Roentgen was experimenting with cathode rays in 1895, he put an activated Crookes tube in a book and went out to lunch. When he returned, he discovered that a key that had also been placed in the book showed up as an image on the developed film!
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| Number | Title | Issue Date |
| 8125176 | Motorized system for closing a building The invention relates to a motorized system for closing a building, of the roller shutter type with the particular feature that it has a two-phase asynchronous motor which comprises two windings (2; 3) and is combined with a speed-varying device (5). | 02/28/2012 |
| 7304446 | Sensorless and brushless DC motor A sensorless and brushless motor is disclosed including a stator, a rotor, a control circuit and an induction coil (50). The stator includes a stator core (30) and a stator coil (34) wound around the stator core. The rotor includes a rotor magne... | 12/04/2007 |
| 7276873 | Fault-handling system for electric power steering system A fault-handling system for a 2-phase motor. When an electric motor is used for power assist in a steering system in a vehicle, malfunctions can cause loss of assist, and detectable vibration. The invention utilizes a 2-phase motor in such an application, and implem... | 10/02/2007 |
| 7276831 | Split-pole field-match motor An electric motor having a plurality of rotor and stator poles, the poles of one element being alternately polarized and neutralized due to the use of direct current and alternating current windings on each pole. The poles of like current are connected in series, an... | 10/02/2007 |
| 7262578 | Direct control of an induction motor This invention relates to sensorless control (i.e. without encoder at the motor shaft) of an induction motor (AC asynchronous motor). In particular, the invention comprises a method for a direct measurement of the electromotive forces (EMF) at the stator of the moto... | 08/28/2007 |
| 7193386 | Apparatus and method for driving a stepping motor The present invention relates to an apparatus for driving a stepping motor, including a plurality of push-pull circuits each of which is capable of controlling a push state in which a current is supplied to a terminal and a pull state in which a current is drawn thr... | 03/20/2007 |
| 7068009 | Drive arrangement, especially for a lifting mechanism and/or a traveling drive The invention concerns a drive arrangement of a lifting gear and/or a traveling gear, with a pole-reversible rotary-current motor with windings for at least two different actuating speeds, with a pole switching element connecting the rotary-current motor to a voltag... | 06/27/2006 |
| 7034499 | Electromagnetic motor An electromagnetic motor with increased torque. The motor has a rotor coil configured to generate a magnetic field. At least two stator coils are connected in series with the rotor coil. Each of the stator coils is configured to generate a respective magnetic field.... | 04/25/2006 |
| 7034498 | Resonant motor system In a resonant motor system, an electrical motor having a stator with one or more windings, a rotor which may or may not be wound, and an air gap between the stator and the rotor for storing magnetic energy such that the motor exhibits a definite electrical inductanc... | 04/25/2006 |
| 6930459 | Method for reducing the influence of a DC current component in the load current of an asynchronous motor A method with which the load current and thus the load moment of an asynchronous motor that is controlled via a phase-controlled two-phase thyristor power controller, can be easily influenced so as to allow a smooth starting operation. According to a first embodimen... | 08/16/2005 |
| 6922038 | Speed control circuit for a dc brushless motor A speed control circuit for a dc brushless motor includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of power supply to thereby cause the switch circuit to output high or low operati... | 07/26/2005 |
| 6885970 | Saliency-based position estimation in permanent magnet synchronous motors A method and system for the sensorless estimation of the states of the mechanical subsystem of a motor are disclosed. In particular, the method and system split the estimation problem into two sub-problems: the estimation of motor parameters as a function of positio... | 04/26/2005 |
| 6847186 | Resonant motor system In a resonant motor system, an electrical motor having a stator with one or more windings, a rotor which may or may not be wound, and an air gap between the stator and the rotor for storing magnetic energy such that the motor exhibits a definite electrical inductanc... | 01/25/2005 |
| 6822419 | Speed control circuit for a DC brushless motor A motor speed control circuit includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of a power supply to thereby cause the switch circuit to output high or low operating voltage to a d... | 11/23/2004 |
| 6037725 | Two step power output motor An electrical control system for an induction motor for achieving optimum efficiency at both full and partial loads at markedly reduced electrical components costs while maximizing reliability over the range of load, and for achieving a two step motor pow... | 03/14/2000 |
| 5952798 | Brushless DC motor assembly control circuit A novel two-phase brushless motor drive assembly. The motor drive assembly is made of two parts, a motor assemble and a motor control circuit. The motor assembly, receives a first wire providing electric power, a second wire providing a ground connection, and ... | 09/14/1999 |
| 5936376 | Excitation circuit for balancing phase voltages in a two phase motor An excitation circuit is disclosed for balancing the phase voltages in a two phase motor. The excitation circuit includes a first and second switch and a port for receiving a signal to drive the switches. The excitation circuit also includes additional el... | 08/10/1999 |
| 5767653 | Variable speed AC induction motor controller A circuit for powering a two-phase AC induction motor. The circuit generates a first signal of the form Vdc+A sin(2πft-0°) and a second signal of the form Vdc+A sin(2πft-90°). The first signal is input to a first error amplifier along with a first sam... | 06/16/1998 |
| 5754025 | Iron core motor device An iron motor device includes an iron core motor the rotor of which is rotationally driven a pre-set angle by electromagnetic induction responsive to phase switching of current supply to two-phase coils wound on an iron core, and a driving control unit fo... | 05/19/1998 |
| 5751131 | Dynamic rate feedback PM motor starting technique A two-phase motor includes two orthogonally disposed stator windings and a permanent magnet rotor. One of the stator windings is energized with a maximum energizing input for a narrow time period, whereupon the rotor is driven to a position intermediate t... | 05/12/1998 |
| 5747958 | Circuit arrangement for powering a two-phase asynchronous motor A power supply circuit for a two-phase asynchronous motor having two windings at a preset angle there-between. The supply circuit has three nodes at which are respectively supplied three node voltages U1, U2, U3 which are derived as logic combinations of ... | 05/05/1998 |
| 5446361 | Circuit arrangement for powering a two-phase asynchronous motor A circuit arrangement for powering a two-phase asynchronous motor having two windings which each have one end connected to one anode and both have another end connected to a third node, the nodes each being arranged to receive one of three alternating vol... | 08/29/1995 |
| 5404088 | Circuit for increasing motor output to compensate for increased load A circuit for boosting the power output of a motor in which a sensor stage, preferably a voltage divider, is coupled to comparator stage, preferably a reverse biased to a diode, which in turn is coupled to a power boost stage, preferably a relay and switc... | 04/04/1995 |
| 5359154 | Conveyor apparatus having plural conveyors with equalized conveying speeds controlled by an inverter means An inverter controlled conveying/measuring apparatus according to the invention includes a conveyor (3) for conveying an object (W) of measurement. The conveyor (3) is driven by an AC motor (M2). Inverter (20) controls and operates the conveyor (3) at a g... | 10/25/1994 |
| 5252904 | Auto reverse circuit A control circuit for connection to a split capacitor motor automatically switches to reverse operation when the motor is caused to stop or slow unacceptably by a heavy load. During operation, a voltage is maintained across a relay winding which is suffic... | 10/12/1993 |
| 5146147 | AC motor drive system A motor drive system for driving a single-phase PSC motor, in which the two motor windings are conductively isolated from each other, from a two phase power source. In one embodiment, the PSC motor is supplied from a two phase inverter circuit. The PSC mo... | 09/08/1992 |
| 5136216 | AC motor drive system A motor drive system for driving a conventional single phase PSC motor from a two-phase power source. In one embodiment, the PSC motor is supplied from a three-phase inverter that is controlled to generate two-phase power. In another embodiment, the PSC m... | 08/04/1992 |
| 5086492 | Switching current regulator for motor control An improved motor control circuit is disclosed in which energy stored in the motor is transferred back to the power supply rather than being passively dissipated. The sense of a feedback signal is reversed at a summation node by combining the signal with ... | 02/04/1992 |
| 4833377 | Current leakage reduction circuit An offset current which is 180° out of phase with the leakage current for a motorized bed circuit is created through the use of an additional transformer winding and series resistor which is connected between the neutral conductor and ground conductor. A... | 05/23/1989 |
| 4100466 | Cold start system for motors Motors, particularly gyro motors, are started by initially operating the motors at a frequency lower than their normal operating frequency so as to draw a larger current and develop greater starting torque with the maximum current and torque limited by a ... | 07/11/1978 |
| 4095150 | Two-phase asynchronous motor For the purpose of providing a two-phase asynchronous motor of the kind comprising a wound stator made up of two portions spacedly disposed parallel to each other and in which the flux flowing in all the field magnets of the stator is exclusively that of ... | 06/13/1978 |
| 4006391 | Linearized pulse width modulator A typical alternating current two phase servomotor has two windings displaced 90°; these windings are normally identified as the reference winding and the control winding. Rotational direction and speed of the motor may be controlled by applying AC volta... | 02/01/1977 |
| 3993940 | Latching system for two-phase reversible motor By actuating a momentary contact switch, an energizing circuit applies an AC voltage directly to one of the two field windings of a two-phase reversible AC induction motor to drive that motor in one of its two directions. As the motor begins to rotate, th... | 11/23/1976 |
