Current sensor with adjustable supply voltage and related method for providing adjustable supply voltage to current sensor

Abstract

A current sensor is provided. For example, a current sensor may comprise: a magnetic core adapted to surround an electrical conductor through which a primary current (Ip) to be measured is flowing; a transducer embedded in the magnetic core to detect a magnetic field induced in the magnetic core by the primary current; a drive amplifier electrically connected to receive a voltage signal from the transducer based on the detected magnetic field; a conductive winding wound around the magnetic core; and an adjustable power supply for providing a supply voltage to the driver amplifier. The conductive winding has a first end electrically connected to receive a secondary current from the drive amplifier and a second end electrically connected to a sampling resistor through which the secondary current flows from the conductive winding. The supply voltage is adjustable based on the frequency of the primary current.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate generally to sensing devices, and more particularly to current sensors. BACKGROUND

[0002] Current sensors, such as Hall-type current sensors, use a fixed supply voltage to power the drive amplifier and other components. The fixed supply voltage must be high enough to provide sufficient power to the current sensor in all situations. However, this means that in some situations, the supply voltage is higher than necessary, resulting in increased power loss and excess heat generation.

[0003] Such current sensors are plagued by technical challenges and limitations. Through the efforts, ingenuity, and innovation of the applicants, many of these identified problems have been solved by developing solutions included in embodiments of the present disclosure, many examples of which are described in detail herein. SUMMARY

[0004] Various embodiments described herein relate to current sensors having an adjustable supply voltage and related methods of providing an adjustable supply voltage to a current sensor.

[0005] According to various embodiments of the present disclosure, a current sensor is provided. In some embodiments, the current sensor includes a magnetic core adapted to surround an electrical conductor through which a primary current (Ip) to be measured is flowing, a transducer embedded in the magnetic core to detect a magnetic field induced in the magnetic core by the primary current, a drive amplifier electrically connected to receive a voltage signal from the transducer based on the detected magnetic field, a conductive winding wrapped around the magnetic core, and an adjustable power supply to provide a supply voltage to the drive amplifier. The conductive winding has a first end electrically connected to receive a secondary current (Is) from the drive amplifier, and a second end electrically connected to a sampling resistor through which the secondary current flows. The supply voltage is adjustable based on a frequency of the primary current.

[0006] In some embodiments, the current sensor further includes a controller including an analog-to-digital controller (ADC). The controller is electrically connected to and receives input from the second end of the conductive winding, and the controller is electrically connected to and sends a control signal to the adjustable power supply to set the supply voltage to the drive amplifier.

[0007] In some embodiments, the supply voltage provided to the drive amplifier is adjustable based on a comparison of the frequency of the primary current to one or more predetermined thresholds.

[0008] In some embodiments, the controller measures the voltage across the sampling resistor (Vs), and the controller uses the measured Vs to calculate Is using the equation Is = Vs / Rs based on a known resistance of the sampling resistor (Rs).

[0009] In some embodiments, when the frequency of the primary current is below a first predetermined threshold, the supply voltage provided to the drive amplifier is a predetermined multiplier times a sum of the voltage across the conducting winding (Vc) and the voltage across the sampling resistor (Vs).

[0010] In some embodiments, the sum of the voltage across the conducting winding and the voltage across the sampling resistor is determined using the equation (Vc + Vs) = (Rc + Rs) * Is, where Rc is a known resistance of the conducting winding.

[0011] In some embodiments, when the frequency of the primary current is at or above a first predetermined threshold but below a second predetermined threshold, the supply voltage provided to the drive amplifier is based on a first predetermined voltage offset added to a voltage value based on the voltage across the conducting winding and the voltage across the sampling resistor. When the frequency of the primary current is at or above the second predetermined threshold, the supply voltage provided to the drive amplifier is based on a second predetermined voltage offset added to the voltage value based on the voltage across the conducting winding and the voltage across the sampling resistor. The second predetermined threshold is higher than the first predetermined threshold, and the second predetermined voltage offset is greater than the first predetermined voltage offset.

[0012] In some embodiments, the voltage value based on the voltage across the conducting winding and the voltage across the sampling resistor is determined by the controller using a delta sigma accumulator.

[0013] In some embodiments, the adjustable power supply includes an adjustable feedback resistor DC-DC buck or boost circuit, a low dropout regulator circuit, or a programmable DC voltage regulator.

[0014] In some embodiments, the multiplier is 1.5, the first predetermined threshold is 400 hertz, the second higher predetermined threshold is 800 hertz, the first predetermined voltage offset is 1 volt, and the second predetermined voltage offset is 5 volts.

[0015] According to various embodiments of the present disclosure, a method of providing an adjustable supply voltage to a current sensor is provided. In some embodiments, the method includes positioning a current sensor such that a magnetic core of the current sensor surrounds an electrical conductor through which a primary current (Ip) to be measured is flowing, and setting a supply voltage provided by an adjustable power supply to a drive amplifier based on a detected frequency of the primary current.

[0016] The foregoing illustrative summary, as well as other exemplary objectives and / or advantages, of the present disclosure and various implementations thereof, are further explained in the following detailed description thereof, taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The description of illustrative embodiments can be read in conjunction with the accompanying drawings. It will be appreciated that the elements illustrated in the figures are not necessarily to scale, for the sake of simplicity and clarity, unless otherwise specifically described. For example, the dimensions of some of the elements can be exaggerated relative to other elements for clarity. Embodiments in conjunction with the teachings of the present disclosure are illustrated and described with respect to the figures presented herein, in which:

[0018] Figure 1 is a simplified circuit diagram of an example current sensor according to example embodiments of the present disclosure;

[0019] Figure 2 is a flowchart illustrating an example method of providing an adjustable supply voltage to a current sensor according to example embodiments of the present disclosure; and

[0020] Figure 3 and Figure 4 is a plot of example adjusted supply voltages for an example current sensor according to alternative example embodiments of the present disclosure. DETAILED DESCRIPTION

[0021] Some embodiments of the present disclosure will now be described to follow, by reference to the accompanying drawings, where some but not all embodiments of the present disclosure are shown. Indeed, these disclosures can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

[0022] As used herein, terms such as "front," "back," "top," "bottom," "left," "right," and the like refer to the example provided below for explanatory purposes to describe the relative location of certain components or portions of components. Moreover, in accordance with the present disclosure, it will be apparent to those of ordinary skill in the art that the terms "substantially" and "about" mean that the referenced element or related description is accurate, plus or minus the appropriate engineering tolerance.

[0023] As used herein, the term "includes" means includes but not limited to, and should be interpreted in the manner it is typically used in the patent context. The use of the more expansive terms "comprising," "including," and "having" should be understood to provide support for narrower

[0024] The phrases “in one embodiment”, “according to one embodiment”, “in some embodiments”, and the like, generally mean that the particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of the present disclosure, and can be included in more than one embodiment of the present disclosure (importantly, such phrases are not necessarily referring to the same embodiment).

[0025] The phrases “in one example”, “according to one example”, “in some examples”, and the like, generally mean that the particular feature, structure, or characteristic following the phrase can be included in at least one example of the present disclosure, and can be included in more than one example of the present disclosure (importantly, such phrases are not necessarily referring to the same example).

[0026] If the specification states a component or feature “may”, “could”, “should”, “would”, “preferably”, “possibly”, “typically”, “optionally”, “for example”, “as an example”, “in some examples”, “often”, or “might” (or other such language) be included or have a characteristic, it does not mean that the particular component or feature is required to be included or to have the characteristic. Such a component or feature can optionally be included in some examples, or it can be excluded.

[0027] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0028] The terms “electronically coupled”, “electronically coupled”, “electronically coupled”, “in communication with”, “in electronic communication with”, or “connected” in the present disclosure refer to two or more elements or components connected by wired and / or wireless means such that signals, voltage / current, data, and / or information can be transmitted to and / or received from the elements or components.

[0029] The term “component” can refer to an article, device, or apparatus that can include one or more surfaces, portions, layers, and / or elements. For example, an example component can include one or more substrates that can provide an underlayer for the component, and can include one or more elements that can form a portion of the substrate and / or be disposed on top of the substrate. In the present disclosure, the term “element” can refer to an article, device, or apparatus that can provide one or more functions.

[0030] Measuring current is important in many systems and applications, and particularly so in electric vehicles (EVs) in which large currents are often used. Current sensors, including but not limited to closed-loop Hall effect sensors, are commonly used to measure current. However, in such current sensors, power dissipation and accompanying excess heat generated due to a higher than necessary fixed supply voltage can result in reduced performance and shorter useful life.

[0031] To address the challenges and limitations associated with conventional current sensors, various examples of the present disclosure can be provided. For example, various examples of the present disclosure can provide example current sensors with an adjustable supply voltage and example methods for providing an adjustable supply voltage to a current sensor. While embodiments of the present disclosure are described herein in relation to closed-loop Hall effect current sensors, the current sensors and methods of embodiments of the present disclosure can be used with any suitable current sensor and in any suitable system and application.

[0032] In various embodiments of the present disclosure, example current sensors are provided in which an adjustable supply achieves an adjustment of the supply voltage based on a frequency of a primary current (i.e., the current being measured). In this regard, the supply voltage is lowered (i.e., lower than conventional fixed supply voltages) to more closely approximate the actual power required, thereby reducing power dissipation and excess heat generation. However, the supply voltage must still be sufficient to power the amplifier and other components of the current sensor. Accordingly, in various embodiments, the adjustable supply voltage is set based on a multiplication of a sum of a voltage across a transconductance winding and a voltage across a sampling resistor of the current sensor by a multiplier, or based on an offset or adder to a sum of a voltage across a transconductance winding and a voltage across a sampling resistor of the current sensor. At this point, the supply voltage will be sufficient to power the amplifier and other components of the current sensor.

[0033] In various embodiments, the supply voltage is adjustable based on a comparison of a frequency of the primary current to one or more predetermined thresholds. In various embodiments, the supply voltage is adjusted differently depending on the frequency of the primary current. In various embodiments, when the frequency of the primary current is below a first predetermined frequency threshold (which can be referred to as a "low frequency mode"), the supply voltage is set based on a predetermined multiplier multiplied by a sum of a voltage across a transconductance winding and a voltage across a sampling resistor of the current sensor.

[0034] In various embodiments, when the frequency of the primary current is above a first predetermined frequency threshold (which can be referred to as a "high frequency mode"), the supply voltage is added to the voltage value based on the voltage across the transconductance electrical winding and the voltage across the sampling resistor of the current sensor based on a first predetermined voltage offset. In various embodiments, a second, higher predetermined frequency threshold can be used in the high frequency mode. In some such embodiments, when the frequency of the primary current is above the second predetermined frequency threshold, the supply voltage is added to the voltage value based on the voltage across the transconductance electrical winding and the voltage across the sampling resistor of the current sensor based on a second, higher predetermined voltage offset.

[0035] Reference is now made to Figure 1 , a simplified circuit diagram of an example current sensor having an adjustable power supply that implements an adjustable supply voltage in accordance with various embodiments of the present disclosure is provided. As Figure 1 depicted in FIG. 1, in various embodiments, such a current sensor 100 measures a primary current (Ip) flowing through an electrical conductor 120. In the illustrated embodiment, the current sensor 100 includes a magnetic core 102 positioned such that the electrical conductor 120 passes through the open center of the magnetic core 102, a transducer 106 embedded in the magnetic core 102 to detect a magnetic field induced in the magnetic core 102 by the primary current, a driver amplifier 108 electrically connected to receive a voltage signal from the transducer 106 based on the detected magnetic field, an electrical winding 104 wrapped around the magnetic core 102, a controller 112, and an adjustable power supply 114 to provide an adjustable supply voltage (Vcc) to the driver amplifier 108 (and other components not shown). The electrical winding 104 has a first end electrically connected to receive a secondary current (Is) from the driver amplifier 108 and a second end electrically connected to a sampling resistor 110 through which the secondary current flows from the electrical winding 104.

[0036] In the illustrated embodiment, the controller 112 includes an analog-to-digital controller (ADC). In some alternative embodiments, a separate ADC can be used. In the illustrated embodiment, the controller 112 is electrically connected to and receives input from the second end of the electrical winding. In this regard, the controller is able to measure the voltage (Vs) across the sampling resistor 110. In various embodiments, the ADC converts the analog voltage Vs to a digital signal. In various embodiments, the controller uses the measured Vs to calculate Is using the equation Is = Vs / Rs based on the known resistance (Rs) of the sampling resistor.

[0037] In the illustrated embodiment, the controller 112 is electrically connected to the adjustable power supply 114 and sends control signals to the adjustable power supply 114 to set the supply voltage for the drive amplifier 108. In various embodiments, any suitable adjustable power supply can be used, including but not limited to an adjustable feedback resistor DC-DC buck or boost circuit, where the output voltage (Vcc) is adjusted by a programmable adjustable resistor; a low dropout regulator circuit, where the output voltage (Vcc) is adjusted by a programmable adjustable resistor; or a programmable DC voltage regulator that receives control signals from the controller 112 via a digital communication interface, such as I2C.

[0038] While components are described in terms of functional limitations, it will be appreciated that at least some of the particular implementations necessarily include the use of particular computing hardware. It will also be appreciated that in some embodiments, certain of the components described herein include similar or common hardware. For example, in some embodiments, both sets of circuitry utilize the use of the same processor(s), memory(ies), circuitry(ies), etc. to perform their related functions, such that duplicative hardware is not needed for each set of circuitry.

[0039] The controller 112 can be embodied in many different ways. In various embodiments, the use of the term “controller,” “microcontroller,” “processor,” or “processing circuitry” should be understood to include a single core processor, a multi-core processor, multiple processors and / or one or more remote or “cloud” processors that are internal or external to the current sensor 100. In some example embodiments, the controller 112 can include one or more processing devices configured to execute independently. Alternatively or additionally, the controller 112 can include one or more processors configured in intandem to enable independent execution of operations, instructions, pipelining, and / or multithreading.

[0040] In example embodiments, the controller 112 can be configured to execute instructions stored in memory circuitry (not shown) or otherwise accessible to the controller. Alternatively or additionally, the controller 112 can be configured to perform hard coded functionality. Thus, whether configured by hardware or software methods, or by a combination thereof, the controller 112 can represent an entity (for example, physically embodied in circuitry) capable of performing operations according to embodiments of the present disclosure while configured accordingly. Alternatively or additionally, the controller 112 can be embodied as a processor of a software that executes instructions, and the instructions, when executed, can specifically configure the controller 112 to perform the various algorithms embodied in one or more operations described herein. In some embodiments, the controller 112 includes hardware, software, firmware, and / or combinations thereof that perform one or more operations described herein.

[0041] In some embodiments, two or more groups of circuitry are combinable. Alternatively or additionally, one or more groups of circuitry perform some or all of the operations and / or functions described herein as being associated with another circuit. In some embodiments, two or more groups of circuitry are combined into a single module embodied in hardware, software, firmware, and / or combinations thereof.

[0042] While the above description provides an example current sensor 100, it is noted that the scope of the present disclosure is not limited to the above description. In some examples, an example current sensor 100 according to the present disclosure can be in other forms. In some examples, an example current sensor 100 can include one or more additional and / or alternative elements, and / or can be configured differently than the one illustrated in Figure 1

[0043] Reference will now be made to Figure 2 , which describes Figure 2 Flowcharts illustrating example steps, procedures, processes, and / or operations in accordance with various embodiments of the present disclosure are provided. Various methods described herein, including for example, methods as shown in Figure 2 , can provide various technical benefits and improvements.

[0044] Reference will now be made to Figure 2 , which illustrates an example method 200. In some embodiments, the example method includes a method for providing an adjustable supply voltage to a current sensor. At step / operation 202, a current sensor (such as, but not limited to, the current sensor 100 described above in connection with Figure 1 , detects a frequency of a primary current (f(Ip)) on a conductor. In various embodiments, to detect the frequency of the primary current, an input from a second end of a conductive winding (which can be referred to as a shunt signal) is collected by a controller of the current sensor (such as, but not limited to, the controller 112 of the current sensor 100 described above in connection with Figure 1 , in various embodiments, the shunt signal is proportional to the current signal on the primary side. In various embodiments, the controller performs a fast Fourier transform (FFT) on the time domain sampled shunt signal and converts the result into a frequency domain signal to obtain the frequency of the primary current.

[0045] At step / operation 204, a controller of the current sensor (such as, but not limited to, the controller 112 of the current sensor 100 described above in connection with Figure 1 , measures a voltage (Vs) across a sampling resistor of the current sensor (such as, but not limited to, the sampling resistor 110 of the current sensor 100 described above in connection with Figure 1 .

[0046] At step / operation 206, the controller of the current sensor (such as, but not limited to, the controller 112 of the current sensor 100 described above in connection with Figure 1 ​The controller 112 of the current sensor 100 described determines that the secondary current Is is flowing through the conductive winding of the current sensor. As described above, in various embodiments, the secondary current (Is) is calculated using the equation Is = Vs / Rs, where Rs is the known resistance of the sampling resistor, and Vs is determined at step / operation 204.

[0047] At step / operation 208, the controller of the current sensor (such as but not limited to the controller 112 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described compares the frequency of the primary current to first and second predetermined frequency thresholds TH1, TH2. Depending on, for example, the speed of the controller, any suitable frequency thresholds can be used. In an example embodiment, the first predetermined threshold is 400 hertz, and the second predetermined threshold is 800 hertz.

[0048] If it is determined at step / operation 208 that the frequency of the primary current is less than the first predetermined frequency threshold, the method 200 enters what can be referred to as a "low frequency mode," and proceeds to step / operation 210. At step / operation 210, the controller of the current sensor (such as but not limited to the controller 112 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described determines the sum of the voltage (Vc) across the conductive winding of the current sensor (such as but not limited to the conductive winding 104 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described determines the sum of the voltage (Vc) across the conductive winding of the current sensor (such as but not limited to the conductive winding 104 of the current sensor 100 described above in connection with

[0049] At step / operation 212, the controller of the current sensor (such as but not limited to the controller 112 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with Figure 3 A graph 300 showing such an example adjusted power supply voltage for an example current sensor in low frequency mode is shown, where the traditional fixed Vcc is shown as a dashed line, the sum of Vc+Vs is shown as a solid line, and the adjusted Vcc is shown as a dotted line. As Figure 3As seen, the adjusted Vcc follows the sum of Vc + Vs, but is larger due to the multiplier. Because this is a low frequency mode, in various embodiments the controller is able to calculate the adjusted supply voltage fast enough so that the adjusted Vcc is able to follow the sum of Vc + Vs. The larger value of the adjusted Vcc compared to the sum of Vc + Vs provides a margin to ensure that the adjusted supply voltage is sufficient to power the drive amplifier and other components of the current sensor in all cases.

[0050] If at step / operation 208 it is determined that the frequency of the primary current is greater than or equal to a first predetermined frequency threshold, the method 200 enters what can be referred to as a "high frequency mode." As described above, in various embodiments when in the high frequency mode, depending on whether there is more than one predetermined frequency threshold, one or more predetermined voltage offsets are added to the voltage value based on the voltage across the transducting winding and the voltage across the sampling resistor of the current sensor.

[0051] In various embodiments, in the high frequency mode, the controller can not be able to repeatedly measure Vs, calculate Is, and then calculate (Rc + Rs) * Is fast enough so that the adjusted Vcc is able to follow the sum of Vc + Vs (as done in the low frequency mode). Thus, in various embodiments the ADC of the controller uses a delta sigma accumulator (which can also be referred to as a de-bounce algorithm) to calculate f(Vc + Vs), and a voltage offset is added to the calculated value of f(Vc + Vs) to determine the adjusted supply voltage.

[0052] In the illustrated embodiment, there are two predetermined frequency thresholds. Thus, in the illustrated embodiment, if at step / operation 208 it is determined that the frequency of the primary current is greater than or equal to a first predetermined frequency threshold TH1 but less than a second predetermined frequency threshold TH2, the method 200 enters what can be referred to as a "lower high frequency mode," and if at step / operation 208 it is determined that the frequency of the primary current is greater than or equal to the second predetermined frequency threshold TH2, the method 200 enters what can be referred to as a "higher high frequency mode." In various embodiments, a first voltage offset is used in the lower high frequency mode, and a second, higher offset is used in the higher high frequency mode. In various embodiments, the use of a higher offset in the higher high frequency mode provides a larger margin because it is more difficult to accurately determine the required supply voltage at higher frequencies.

[0053] If at step / operation 208 it is determined that the frequency of the primary current is greater than or equal to the first predetermined frequency threshold TH1 but less than the second predetermined frequency threshold TH2, the method 200 proceeds to step / operation 214. At step / operation 214, the controller of the current sensor (such as but not limited to the controller 102 described above in connection with FIG. 1) calculates the voltage across the sampling resistor of the current sensor, Vss, and adds a first voltage offset to the calculated value of Vss to determine the adjusted supply voltage. Figure 1The controller 112 of the current sensor 100 described uses a delta sigma accumulator to determine f(Vc+Vs).

[0054] At step / operation 216, the controller of the current sensor (such as but not limited to the controller 112 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with

[0055] If at step / operation 208 it is determined that the frequency of the primary current is greater than or equal to a second predetermined frequency threshold TH2, the method 200 proceeds to step / operation 218. At step / operation 218, the controller of the current sensor (such as but not limited to the controller 112 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with

[0056] At step / operation 220, the controller of the current sensor (such as but not limited to the controller 112 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with Figure 1 The controller 112 of the current sensor 100 described sends a signal to the adjustable power supply (such as but not limited to the adjustable power supply 114 of the current sensor 100 described above in connection with

[0057] Figure 4 A plot 400 showing such an example adjusted power supply voltage for an example current sensor in a high frequency mode is shown, where the conventional fixed Vcc is shown as a dashed line, the sum of Vc+Vs is shown as a solid line, f(Vc+Vs) is shown as a dotted line, and the adjusted Vcc is shown as a dash-dot line. As Figure 4As seen, the sum of Vc + Vs has three different time periods: a first time period 402 in which the frequency of the primary current is between TH1 and TH2 (i.e., the lower high frequency mode), a second time period 404 in which the frequency of the primary current is greater than or equal to TH2 (i.e., the higher high frequency mode), and a third time period 406 in which the frequency of the primary current is between TH1 and TH2 (i.e., the lower high frequency mode). Thus, a first predetermined voltage offset (Voffseti) is added to f(Vc + Vs) in the first time period, a second predetermined voltage offset (Voffset2) is added to f(Vc + Vs) in the second time period, and the first predetermined voltage offset (Voffseti) is added to f(Vc + Vs) in the third time period.

[0058] In some embodiments, the method 200 is continuously repeated each time the current sensor is operating to measure the primary current.

[0059] The operations and processes described herein support combinations of means for performing the specified functions and combinations of operations for performing the specified functions. It will be understood that one or more operations and combinations of operations can be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of computer program products and special purpose hardware-based computer systems which perform specified functions.

[0060] In some example embodiments, certain ones of the operations herein can be modified or further amplified as described below. Moreover, in some embodiments additional optional operations can also be included. It should be appreciated that each of the modifications, optional additions or amplifications can be included with the operations described herein either alone or in combination with any others among the features described herein.

[0061] The foregoing method and process descriptions are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by one of ordinary skill in the art, the order of steps in the foregoing embodiments can be performed in any order. Words such as "thereafter," "then," "next," "after" and the like used herein are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the methods. Furthermore, any reference to claim elements in the singular, for example, using the articles "one," "the" or "said," is not to be construed as limiting the element to the singular.

[0062] While various embodiments based on the principles disclosed herein have been shown and described above, modifications can be made by those skilled in the art without departing from the teachings of this disclosure. The embodiments described herein are merely representative and are not intended to be limiting. Many variations, combinations, and modifications are possible and are within the scope of this disclosure. Alternative embodiments resulting from combining, integrating, and / or omitting features of one or more embodiments are also within the scope of this disclosure. Therefore, the scope of protection is not limited by the description set forth above, but is defined by the following claims, which include all equivalents of the subject matter of the claims. Each claim is incorporated into the specification as further disclosure, and the claims are embodiments of this disclosure. Furthermore, any advantages and features described above may relate to particular embodiments, but the application of such published claims should not be limited to processes and structures that achieve any or all of the above advantages or have any or all of the above features.

[0063] Furthermore, the section headings used herein are provided for consistency with the recommendations of 37C.FR1.77, or otherwise to provide organizational clues. These headings should not limit or characterize the disclosure that may be set forth in any of the claims of this disclosure. For example, the description of the technology in the “Background Art” section should not be construed as an admission that certain technology is prior art to any disclosure in this disclosure. Nor should the term “Summary of the Invention” be considered a limiting characterization of the disclosure set forth in the published claims. Furthermore, any reference in this disclosure to the singular “disclosure” or “embodiment” should not be used to argue that there is only a single point of novelty in this disclosure. Multiple embodiments of this disclosure may be set forth according to the limitations of the multiple claims of this disclosure, and such claims accordingly define this disclosure and its protected equivalents. In all cases, the scope of the claims should be considered in light of the advantages of this disclosure in itself, but should not be limited by the headings set forth herein.

[0064] Furthermore, without departing from the scope of this disclosure, the systems, subsystems, apparatuses, technologies, and methods described and illustrated as discrete or separate in the various embodiments may be combined or integrated with other systems, modules, technologies, or methods. Other devices or components shown or discussed as coupled or communicating with each other may be indirectly coupled through some intermediate devices or components, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are as can be determined by those skilled in the art and may be made without departing from the scope of this disclosure.

[0065] Those skilled in the art who have the benefit of the teachings of the preceding description and associated drawings will appreciate many modifications and other embodiments thereof. While only certain components of the devices and systems described herein are specifically addressed in the foregoing description, a variety of other components can be used in combination with the components and structures disclosed herein. Thus, it is to be understood that the present disclosure is not limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. For example, various elements or components can be combined, rearranged, integrated, or omitted, certain features can be utilized independently, and / or certain features can be used with other systems. Additionally, the steps of any of the methods described above can not necessarily be performed in the order described, and in certain circumstances, portions of one or more steps can be performed in a substantially simultaneous manner. Although specific terminology is employed by various embodiments, the terms are used in a generic and descriptive sense only, and not for purposes of limitation.

Claims

1. A current sensor comprising: a magnetic core adapted to surround an electrical conductor through which a primary current (Ip) to be measured is flowing; a transducer embedded in the magnetic core for detecting a magnetic field induced in the magnetic core by the primary current; a drive amplifier electrically connected to receive a voltage signal from the transducer based on the detected magnetic field; a conductive winding wrapped around the magnetic core, the conductive winding having a first end electrically connected to receive a secondary current (Is) from the drive amplifier and a second end electrically connected to a sampling resistor through which the secondary current flows from the conductive winding; and an adjustable power supply for providing a supply voltage to the drive amplifier, the supply voltage being adjustable based on a frequency of the primary current.

2. The current sensor of claim 1, further comprising a controller, the controller comprising an analog-to-digital controller (ADC); wherein the controller is electrically connected to and receives input from the second end of the conductive winding; and wherein the controller is electrically connected to and sends a control signal to the adjustable power supply to set the supply voltage to the drive amplifier.

3. The current sensor of claim 2, wherein, The supply voltage provided to the drive amplifier is adjustable based on a comparison of the frequency of the primary current to one or more predetermined thresholds.

4. The current sensor of claim 3, wherein the controller measures a voltage (Vs) across the sampling resistor; and wherein the controller uses the measured Vs, based on a known resistance (Rs) of the sampling resistor, to calculate Is using the equation Is = Vs / Rs.

5. The current sensor of claim 4, wherein, The supply voltage provided to the drive amplifier is a predetermined multiplier times a sum of a voltage (Vc) across the conductive winding and a voltage (Vs) across the sampling resistor when the frequency of the primary current is below a first predetermined threshold.

6. The current sensor of claim 5, wherein, The sum of the voltage across the conductive winding and the voltage across the sampling resistor is determined using the equation (Vc + Vs) = (Rc + Rs) * Is, where Rc is a known resistance of the conductive winding.

7. The current sensor of claim 5, wherein, The supply voltage provided to the drive amplifier is a first predetermined voltage offset added to a voltage value based on the voltage across the conductive winding and the voltage across the sampling resistor when the frequency of the primary current is at or above the first predetermined threshold but below a second predetermined threshold, the second predetermined threshold being higher than the first predetermined threshold; and wherein the supply voltage provided to the drive amplifier is a second predetermined voltage offset added to a voltage value based on the voltage across the conductive winding and the voltage across the sampling resistor when the frequency of the primary current is at or above the second predetermined threshold; and wherein the second predetermined voltage offset is greater than the first predetermined voltage offset.

8. The current sensor of claim 7, wherein the voltage value based on the voltage across the conductive winding and the voltage across the sampling resistor is determined by the controller using a delta sigma accumulator.

9. The current sensor of claim 7, wherein the adjustable power supply comprises an adjustable feedback resistance DC-DC buck or boost circuit, a low dropout regulator circuit, or a programmable DC voltage regulator.

10. The current sensor of claim 7, wherein the predetermined multiplier is 1.5; wherein the first predetermined threshold is 400 hertz; wherein the second, higher, predetermined threshold is 800 Hertz; wherein the first predetermined voltage offset is 1 volt; and wherein the second predetermined voltage offset is 5 volts.

11. A method of providing an adjustable supply voltage to a current sensor, the method comprising: positioning a current sensor so that a magnetic core of the current sensor surrounds an electrical conductor through which a primary current (Ip) to be measured is flowing, the current sensor further comprising: (a) a transducer embedded in the magnetic core for detecting a magnetic field induced in the magnetic core by the primary current; (b) a drive amplifier electrically connected to receive a voltage signal from the transducer based on the detected magnetic field; (c) an electrically conductive winding wrapped around the magnetic core, the electrically conductive winding having a first end electrically connected to receive a secondary current (Is) from the drive amplifier and a second end electrically connected to a sampling resistor through which the secondary current flows from the electrically conductive winding; and (d) an adjustable power supply for providing a supply voltage to the drive amplifier; detecting a frequency of the primary current; and setting the supply voltage provided by the adjustable power supply to the drive amplifier based on the determined frequency of the primary current.

12. The method of claim 11, wherein the current sensor further comprises a controller, the controller comprising an analog-to-digital controller (ADC); wherein the controller is electrically connected to the second end of the conductive winding; wherein the controller is electrically connected to the adjustable power supply; and wherein the method further comprises: receiving, by the controller, an input from the second end of the conductive winding; and sending, by the controller, a control signal to the adjustable power supply to set the supply voltage provided to the drive amplifier.

13. The method of claim 12, further comprising comparing, by the controller, the frequency of the primary current to one or more predetermined thresholds; wherein the supply voltage provided to the drive amplifier is set based on the comparison of the frequency of the primary current to the one or more predetermined thresholds.

14. The method of claim 13, further comprising: measuring, by the controller, a voltage (Vs) across a sampling resistor; and calculating, by the controller, Is using the measured Vs, based on a known resistance (Rs) of the sampling resistor, using the equation Is = Vs / Rs.

15. The method of claim 14, further comprising: determining, by the controller, whether the primary current is below a first predetermined threshold; and if the primary current is determined to be below the first predetermined threshold, the supply voltage provided to the drive amplifier is a predetermined multiplier times a sum of a voltage (Vc) across the conductive winding and a voltage (Vs) across the sampling resistor.

16. The method of claim 15, wherein, determining the sum of the voltage across the conductive winding and the voltage across the sampling resistor using the equation (Vc + Vs) = (Rc + Rs) * Is, where Rc is a known resistance of the conductive winding.

17. The method of claim 15, wherein, when the frequency of the primary current is at or above the first predetermined threshold but below a second predetermined threshold, the second predetermined threshold being higher than the first predetermined threshold, the supply voltage provided to the drive amplifier is based on a first predetermined voltage offset added to a voltage value based on the voltage across the conductive winding and the voltage across the sampling resistor; and wherein, when the frequency of the primary current is at or above the second predetermined threshold, the supply voltage provided to the drive amplifier is based on a second predetermined voltage offset added to a voltage value based on the voltage across the conductive winding and the voltage across the sampling resistor; and wherein the second predetermined voltage offset is greater than the first predetermined voltage offset.

18. The method of claim 17, wherein the voltage value based on the voltage across the conductive winding and the voltage across the sampling resistor is determined by the controller using a delta sigma accumulator.

19. The method of claim 17, wherein the adjustable power supply comprises an adjustable feedback resistor DC-DC buck or boost circuit, a low dropout regulator circuit, or a programmable DC voltage regulator.

20. The method of claim 17, wherein the predetermined multiplier is 1.5; wherein the first predetermined threshold is 400 hertz; wherein the second, higher predetermined threshold is 800 hertz; wherein the first predetermined voltage offset is 1 volt; and wherein the second predetermined voltage offset is 5 volts.

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