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!
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 |
| 7420345 | Circuit for driving an appliance for treating laundry A circuit for driving an appliance for treating laundry, includes a motor circuit having an AC motor, and a door-locking circuit. The motor circuit and the door-locking circuit may be driven by a single common electronic switching element. ... | 09/02/2008 |
| 7358700 | Induction motor controller An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of... | 04/15/2008 |
| 7298105 | Motor speed estimation system and method using hybrid model reference adaptive system Motor drives, motor speed controllers, motor speed estimation systems, and methods are presented for controlling motor speed and for estimating motor speed, in which a speed estimate controller provides a rotor speed estimate based on a first error term from a torqu... | 11/20/2007 |
| 7193387 | System and method for motor speed estimation using hybrid model reference adaptive system Motor drives, motor speed controllers, motor speed estimation systems, and methods are presented for controlling motor startup speed and for estimating motor speed during startup, in which a speed estimate controller provides a rotor speed estimate based on a first ... | 03/20/2007 |
| 6633144 | System and method for measuring parameters of a DC motor field A system and method determine the parameters of a field of a DC motor. The method comprises obtaining parameters of the DC motor; and performing an iterative processing loop, the iterative processing loop being performed n times. The iterative processing ... | 10/14/2003 |
| 6346789 | Motor step-less speed control with active feedback of phase detector An apparatus for and method of controlling the circulating fan of a gas appliance. The circulating fan is powered by an alternating current electric motor. An electronic circuit, powered by the heat of the gas appliance, determines the rotational speed of... | 02/12/2002 |
| 6278623 | System and method for compensating for voltage notches in two-phase phase locked loops A method and system for compensating for voltage notches in phase locked loop (PLL) control devices. A bridge firing controller receives signals representative of two of the line to line voltages received by the bridge. The controller includes a PLL synch... | 08/21/2001 |
| 5955794 | Method and arrangement for controlling the output of a load connected to an ac line voltage A method and arrangement for controlling the output of electrical consumers connected to ac line voltage, especially of electric motors and the like, in which the output is changed by changing the phase control of the electric alternating magnitude suppli... | 09/21/1999 |
| 5675228 | Methods and apparatus for controlling energization of a motor Methods and apparatus for controlling energization of an appliance motor are described. The apparatus, in one embodiment, may include a condition responsive switch secured within an appliance motor casing to control the energization of the appliance motor... | 10/07/1997 |
| 5512810 | Variable speed control for a hand-held electric power tool A power tool has a variable speed control circuit that comprises a user switch, a motor and a thyristor connected in series between a pair of power supply terminals. A manually variable resistor is connected between a first electrode of the thyristor and ... | 04/30/1996 |
| 5323095 | Propulsion and electric braking system for electric traction motor vehicle A system and method for controlling power transfer between an internal combustion driven electrical power generator and a direct current (DC) motor. In one form, the invention includes control of a power inverter in a manner to restrict current through a ... | 06/21/1994 |
| 5247230 | Unilateral diac for motor speed control A universal diac is provided for implementation in controlling an SCR in a motor speed control circuit. The diac is provided with dissimilar interconnections between the emitters and base, such that the device operates as a standard diac in one mode of op... | 09/21/1993 |
| 5235259 | Apparatus and method for controlling a motor An apparatus and method for controlling a motor used for rotating a drill stem is disclosed. Silicon control rectifier based system regulates the power to the motor. A control unit coupled to the SCR regulator and the motor monitors the motor input curren... | 08/10/1993 |
| 4947099 | Motor controller with optical SCR's A three-phase electric motor is coupled to each phase line of an electric source by pairs of SCR's coupled in inverse parallel relationship. One of the SCR's in each pair is triggered by a signal from a conventional motor control circuit which regulates t... | 08/07/1990 |
| 4888813 | Electronic speed control interlock A motor controller for use on a treadmill to prohibit the treadmill from operating at a high speed immediately upon energization. The controller uses solid state circuitry in a motor speed circuit with a speed setting potentiometer set by the user. The sy... | 12/19/1989 |
| 4873473 | Modular motor controller An apparatus for controlling a motor comprises an oscillator for providing a source of periodic signals, and a divider for converting the oscillator output into desired motor rotation frequency signals. A tachometer generates actual motor rotation frequen... | 10/10/1989 |
| 4851744 | Feedback circuitry for D.C. motor speed control A circuit for controlling the speed of a DC motor provides delay and sampling means in the feedback loop to delay the triggering of the SCRs driving the DC motor and measured the motor armature voltage during the period of the delay, thereby eliminating e... | 07/25/1989 |
| 4842190 | Control circuit for a forced-air heating system A control circuit for a forced-air heating system comprises a silicon diode that is positionable in thermally-conductive relationship with the interior space of a furnace plenum. A current source supplies current to the silicon diode, and the potential dr... | 06/27/1989 |
| 4827202 | Method of and circuitry for automatically adjusting the variable-gain amplification in a control loop In a control loop for automatically adjusting variable-gain amplification, a sinusoidal signal with a frequency fo that is critical for the control loop is superimposed over a positioning parameter W. Two synchronous rectifiers S1 and S2 filter... | 05/02/1989 |
| 4823055 | Electronic control circuit for command systems A control circuit for a closed loop command system having an output which is adjusted to conform with an input command level. A pulse generator provides digital pulses with durations representative of the output of the system. Command pulses are generated... | 04/18/1989 |
| 4818923 | Method of, and apparatus for, regulating the rotational speed of an electric motor in a four quadrant mode of operation An inexpensive and reliable regulating apparatus contains between a regulating unit and an electric motor series-connected therewith a feedback path for a single tachometer signal and including a band-pass filter. The band-pass filter determines the opera... | 04/04/1989 |
| 4804895 | Charge balancing current sampler for a digital motor control An analog current sensing circuit is controlled by a current loop microprocessor. An integrator circuit stores charge which is the integral of armature current in a motor. The output is read by the microprocessor and divided by a time value to determine a... | 02/14/1989 |
| 4803410 | Variable duty ratio speed controller for DC motors A speed controller for a DC motor includes a semiconductor switching device connected in series with it in a DC power circuit. The switching circuit is turned on and off with a duty ratio variable as a function of motor load. A time constant circuit inclu... | 02/07/1989 |
| 4794310 | Phase angle control circuit for motors A control circuit for d-c motors, which are supplied by an a-c supply through phase angle control, and which obtains information regarding the actual current value from a current transformer secondary voltage, and which is utilized additionally also for d... | 12/27/1988 |
| 4789135 | Operating device for electric hoist An operating device for an electric hoist having a DC motor for raising and lowering an object, comprises a low speed adjusting setting unit (VR1) and a high speed adjusting setting unit (VR2) provided in a control box of the hoist. The operating device f... | 12/06/1988 |
| 4788478 | Speed control system for DC motor A speed control system for a DC motor is disclosed. This system includes a first transistor connected between a first terminal and a reference terminal, a second transistor connected between a second terminal and the reference terminal, an error amplifier... | 11/29/1988 |
| 4788479 | Control mechanism for a separately excited DC drive motor and method for control of a DC drive motor In combination, a control mechanism for a separately excited DC drive motor, and a device for generating an exciter current to be supplied to a field winding of the motor, includes a measuring device for measuring operational values of the motor, and a de... | 11/29/1988 |
| 4780654 | Control apparatus for drilling machine A drilling machine comprises an electric drill having a drill motor for rotating an annular drilling tool and a feed control motor for moving the annular drilling tool forward and backward with respect to a workpiece, both connected to an AC power source,... | 10/25/1988 |
| 4769582 | Low vibration pulse drive device for an electric motor A pulse-drive circuit for an electric motor in which the steep edges in the drive-signal are made to vary substantially stepwise, i.e. around a first time instant the signal changes from a first level to a second level and around a second instant the sign... | 09/06/1988 |
| 4769557 | Modular electric load controller An electric load controller having a modular construction with the logic circuitry located in an enclosure. This circuitry comprises a microprocessor, I/O interface and a memory for storing the computer program to be executed by the microprocessor. The co... | 09/06/1988 |
| 4761591 | RPM regulation of an electromotor A device for regulating the RPM of an electromotor with an RPM generator coupled to it for generating pulses, measures the intervals between the pulses of a measure of the RPM of the motor. The device includes an oscillator for generating clock signals, w... | 08/02/1988 |
| 4751439 | Multiple chopper speed control system for compound motor A compound-motor speed control system for a battery-powered vehicle (86) wherein the series winding (14) and the shunt winding (16) of the motor (12) are magnetically linked in energy transfer relation. A first current switch (18) is connected in series w... | 06/14/1988 |
| 4734629 | Variable speed trigger switch A variable speed trigger switch particularly adapted for use with electric power tools such as drills. The trigger switch features clam shell construction and a single vertically disposed circuit board thereby facilitating assembly and resulting in a low ... | 03/29/1988 |
| 4733146 | Energy recovery system for cyclic drives A system is disclosed for recovering and storing the energy generated by an electrical motor during deceleration so as to be available for use when the motor is subsequently accelerated. The system utilizes a capacitor for storing the energy produced by v... | 03/22/1988 |
| 4716535 | Speed detection apparatus A speed detection apparatus for detecting speed of electric equipment on the basis of a sampling interval so as to stably operate a variable speed control system connected thereto. The sampling interval is varied in accordance with an input current to be ... | 12/29/1987 |
| 4716348 | DC motor adaptive controller A method for operating a DC motor controller according to a first gain when the armature current of the DC motor is discontinuous, according to a second gain when the armature current is continuous, and according to a third gain when the armature current ... | 12/29/1987 |
| 4703248 | Switching arrangement for full-wave power control which is insensitive to mains voltage fluctuations A switching arrangement for full-wave power control comprising a triac (2), the control electrode of which is preceded by a trigger diode, the control voltage being taken from an RC section having at least one potentiometer (9), which effects a phase shif... | 10/27/1987 |
| 4697126 | Control method for direct current motor A method of controlling a direct current motor operating in an essentially no torque, discontinuous current mode provides for delivering current pulses to the motor of alternate relative polarity so as to position the motor to rapidly respond to a command... | 09/29/1987 |
| 4686393 | Circuit breakers for direct and alternating current Circuit breakers which employ a capacitor to pass a current in opposition to a load current through a thyristor when interruption is required suffer from the disadvantage that high switching over-voltages occur. In the present invention current is diverte... | 08/11/1987 |
| 4636935 | Power control system A solid state control device is disclosed for controlling power turn-on times to process systems such as heaters used in glassmaking, in petrochemical plants, in furnaces, and for electromotive, and other devices. A command signal from the process control... | 01/13/1987 |
