Did You Know...
...that after Parker Brothers executives turned down the game of Monopoly because it had "52 fundamental errors" (including taking too long to play), a copy of the game wound up in the home of the company president who stayed up until 1 a.m. to finish playing it? He was so impressed by the game that the next day he wrote to inventor Charles Darrow and offered to buy it!
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| Number | Title | Issue Date |
| 7368887 | Servo control device and method of adjusting servo system A servo control device that displays, by a two-dimensional image, evaluation of control precision of a servo system, includes: an instruction unit that instructs a position instruction having periodicity; a unit that records a track of position data based on a posit... | 05/06/2008 |
| 7253575 | Industrial optical shutter A highly versatile optical shutter for industrial and scientific applications is disclosed. The has a aperture which defines a light path through the shutter, and a shutter vane or blade that is moved into and out of the light path using a precision, microprocessor ... | 08/07/2007 |
| 7102326 | Motor speed variator and a driving method thereof A motor variator and a driving method thereof are provided for controlling the operating speed of a fan, which employ an alternate current chopper to change the working cycle and the rotary speed of a stepless motor. The motor variator includes a high-frequency alte... | 09/05/2006 |
| 7084602 | Predicting wheel slip and skid in a locomotive The present invention is directed to the termination of the occurrence of wheel slip/skid and prediction and prevention of the onset of wheel slip/skid in a locomotive. In one configuration, a lookup table of adhesion factors is used to predict the occurrence of whe... | 08/01/2006 |
| 7064507 | Managing wheel skid in a locomotive The present invention is directed to the termination of the occurrence of wheel slip/skid and prediction and prevention of the onset of wheel slip/skid in a locomotive. In one configuration, a lookup table of adhesion factors is used to predict the occurrence of whe... | 06/20/2006 |
| 7005824 | Shutter mechanism including stepping motor control apparatus with upper and lower limit stopping position control A shutter mechanism includes a drum (2), a stepping motor (5), a driver (20), a microcomputer (10), a memory (16), and a load magnitude detection circuit (30) that detects the magnitude of the load on the stepping motor (... | 02/28/2006 |
| 6980477 | Chopper sensor for MRAM A sensor for a magnetic random-access memory (MRAM) of an embodiment of the invention includes an amplifier having at least two inputs and at least two outputs. The inputs are coupled to a magnetic storage element of the MRAM having a resistance corresponding to a v... | 12/27/2005 |
| 6781336 | Method and apparatus for controlling electric servo actuators A servomechanism having an actuator configured to convert electrical energy into mechanical energy and a controller configured for electrical connection to a power source. A power cable electrically connects the actuator and the controller. The power cable is config... | 08/24/2004 |
| 6759817 | Window lifter system and method of controlling a plurality of window lifters A window lifter system comprises a first window lifter motor and a master control device for the first window lifter motor. The master control device is able to detect a position of a window pane driven by the first window lifter motor and to drive the first window ... | 07/06/2004 |
| 6617818 | Voltage independent PWM base frequency generating method A DC brushless motor operation speed control method is disclosed. First, a linearly voltage dependent current source is used to charge a capacitor and the terminal voltage of the capacitor is coupled to a linearly voltage dependent base frequency level de... | 09/09/2003 |
| 5910715 | Current control apparatus in DC motor The present invention provides a current control apparatus for a DC motor system having a motor field coil and a motor armature and driven by the power of a battery, and a chopper transistor for controlling the amount of the current supplied to the DC mot... | 06/08/1999 |
| 5619112 | Bi-directional electric torque motor and driver A limited angle torque motor and control circuit are adapted to convert an electrical demand signal of varying magnitude into a motor shaft position relating to the magnitude of the demand signal. More particularly, a bidirectional motor is provided havin... | 04/08/1997 |
| 5298871 | Pulse width modulation signal generating circuit A microcomputer having a signal generating circuit which generates pulse width modulation signals defined by a carrier wave, and which controls controlled portions according to pulse width modulating signals. The signal generating circuit comprises a carr... | 03/29/1994 |
| 4539608 | Low offset position demodular A low offset position demodulator that may be used in the positioning servo of a disk drive or similar device. A first stage of the demodulator circuit multiplies or switches a servo carrier signal, modulated with position information, with a synchronized... | 09/03/1985 |
| 4480938 | Printer escapement servomotor drive with a minimum power supply A servomotor drive system for a printer escapement is provided which minimizes power supply requirements. The drive system has means for accelerating and decelerating the printhead escapement having a fixed current source applied to a servomotor which dri... | 11/06/1984 |
| 4337426 | Stabilized servo motor positioning apparatus A photoelectric transducer (14) produces first and second periodic signals (A), (B) which are 90° out of phase with each other in response to rotation of a servo motor shaft (12a). The first and second signals (A), (B) are differentiated, directly full w... | 06/29/1982 |
| 4328451 | Device for controlling the electric drive motor of a window raiser in particular in an automobile vehicle The device comprises for each window an electric driving motor and a selector which is adapted to ensure the selective supply of current to the motor, in one direction or the other, through a control circuit acting on a supply source. The supply source is... | 05/04/1982 |
| 4232259 | Servo-system A servo-system includes a high-gain direct-coupled direct current (dc) differential amplifier to which a dc input signal is fed. An adder adds the dc amplifier output to a comparison voltage, and the adder output is applied through a filter circuit to a s... | 11/04/1980 |
| 4161678 | Servo-system A servo-system is provided for self-balancing systems using an ac servomotor capable of maintaining loop gain substantially constant irrespective of span adjustment and without capacitor coupling. It includes a direct-coupling dc amplifier for comparing i... | 07/17/1979 |
| 4016471 | Level detection system having a band-pass characteristic and a servo system including the same A level detection system and a servo system employing the level detection system are disclosed. The level detection and servo system employs the use of a reasonably broad band-pass characteristic to avoid criticality in narrow band-pass systems. The level... | 04/05/1977 |
