Patents Assigned to Load Controls Incorporated
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Patent number: 5930092Abstract: The electrical power to a device, such as a pump, is monitored by multiplying a current signal with a voltage signal to provide a power signal. Typically when the power signal is outside a predetermined range, power to the device is interrupted.Type: GrantFiled: January 17, 1992Date of Patent: July 27, 1999Assignee: Load Controls, IncorporatedInventor: Robert W. Nystrom
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Patent number: 5754421Abstract: Electrical power monitoring apparatus comprises a loop and a first conductor. A current sensor coupled to the first conductor provides a current signal that is representative of the current in the first conductor. A voltage sensor coupled at least to the first conductor provides a voltage signal that is representative of the voltage on the first conductor relative to that on a reference terminal. A multiplier coupled to the current sensor and voltage sensor has a power output which provides a power signal that is proportional to the instantaneous value of electrical power carried by the first conductor. A calibration circuit in the loop has an input coupled to the power output and has an adjustable output. A current regulator in the loop has an input coupled to the adjustable output to maintain the current in the loop between predetermined minimum and maximum loop current values.Type: GrantFiled: July 7, 1995Date of Patent: May 19, 1998Assignee: Load Controls, IncorporatedInventor: Robert W. Nystrom
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Patent number: 5467012Abstract: Electrical power monitoring apparatus comprises a loop and a first conductor. A current sensor coupled to the first conductor provides a current signal that is representative of the current in the first conductor. A voltage sensor coupled at least to the first conductor provides a voltage signal that is representative of the voltage on the first conductor relative to that on a reference terminal. A multiplier coupled to the current sensor and voltage sensor has a power output which provides a power signal that is proportional to the instantaneous value of electrical power carried by the first conductor. A calibration circuit in the loop has an input coupled to the power output and has an adjustable output. A current regulator in the loop has an input coupled to the adjustable output to maintain the current in the loop between predetermined minimum and maximum loop current values.Type: GrantFiled: May 10, 1994Date of Patent: November 14, 1995Assignee: Load Controls IncorporatedInventor: Robert W. Nystrom
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Patent number: 5003252Abstract: An apparatus and method for sensing power factor and torque on the output of a variable frequency machine is disclosed. Initially, power is sensed in each phase of the three-phase machine by utilizing Hall generators for multiplying the phase current flowing through each phase by a current proportional to a phase voltage for each phase. The products are then summed to obtain a reading of the instantaneous power drawn by the three phase machine. The AC component is filtered out of the summed signal using a multistage filter which allows for maintaining a fast response time with low ripple. This output is divided by the speed of the machine and multiplied by a constant to result in a signal representing torque. For measuring power factor, power signal sensed in each phase is applied to a DC blocking capacitor, effectively separating the AC envelope proportional to voltage times current. The three signals are applied to absolute value amplifiers and summed to provide a signal yielding total power.Type: GrantFiled: August 16, 1989Date of Patent: March 26, 1991Assignee: Load Controls IncorporatedInventor: Robert W. Nystrom
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Patent number: 4764720Abstract: Disclosed is an apparatus and method for sensing power in a variable frequency machine. The power is sensed in each phase of the three phase machine by utilizing Hall generators for multiplying the phase current flowing through each phase by a current proportional to a phase voltage for each phase. The products are then summed to obtain a reading of the instantaneous power drawn by the three phase machine. The AC component is filtered out of the summed signal using a multi-stage filter which allows for maintaining of a fast response time with low ripple. In a preferred embodiment, a four stage filter utilizing R.C. filters is employed for this purpose.Type: GrantFiled: July 22, 1987Date of Patent: August 16, 1988Assignee: Load Controls IncorporatedInventor: Robert W. Nystrom
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Patent number: D340698Type: GrantFiled: July 31, 1991Date of Patent: October 26, 1993Assignee: Load Controls, IncorporatedInventor: Robert W. Nystrom