Precision current sensing using low cost sense resistance

An apparatus, comprising:

• a precision current sensing system configured to accurately measure current, comprising:
• a current sensing element;
• a current supply connected in series with the current sensing element;
• a processor, operably coupled with the current supply to govern the current supplied by the current supply;
• wherein, the processor is operably coupled with the current sensing element to measure the voltage drop generated across the current sensing element when the current supply is activated;
• and,
• a memory that is not a transitory propagating signal, the memory connected to the processor and encoding computer readable instructions, including processor executable program instructions, the computer readable instructions accessible to the processor, wherein the processor executable program instructions, when executed by the processor, cause the processor to perform operations comprising:
• sense current in the current sensing element;
• correct inaccuracy measured in the sensed current;
• and,
• measure the precise current sensed in the current sensing element with the measured inaccuracy corrected.

An apparatus, comprising:

• a precision current sensing system configured to accurately measure current in a current sense resistance, comprising:
• a current sensing element, comprising:
• a low-cost non-precision current sense resistance;
• and,
• sensor signal conditioning circuitry operably coupled with the low-cost non-precision current sense resistance, wherein the signal conditioning circuitry is configured to correct sensing element non-ideality over temperature, sensing current value, and variation in the sensing element material;
• and,
• a current supply connected in series with the low-cost non-precision current sense resistance;
• a processor, operably coupled with the current supply to govern the current supplied by the current supply;
• wherein, the processor is operably coupled with the low-cost non-precision current sense resistance to measure the voltage drop generated across the low-cost non-precision current sense resistance when the current supply is activated;
• and,
• a memory that is not a transitory propagating signal, the memory connected to the processor and encoding computer readable instructions, including processor executable program instructions, the computer readable instructions accessible to the processor, wherein the processor executable program instructions, when executed by the processor, cause the processor to perform operations comprising:
• sense current in the low-cost non-precision current sense resistance, based on measuring the voltage drop generated by the current supply across the low-cost non-precision resistance when the current supply is activated;
• correct inaccuracy measured in the sensed current, based on calculating calibration coefficients determined as a function of the current sensed in the low-cost non-precision resistance by measuring at a plurality of temperatures the voltage drop generated by a plurality of currents determined as percentages of the current supply full scale current;
• and,
• measure the precise current sensed in the low-cost non-precision current sense resistance with the measured inaccuracy corrected.