In an example method of trimming a voltage reference circuit, the method includes: setting the circuit to a first temperature; trimming a first resistor (R.sub.DEGEN) of a differential amplifier stage of the circuit; and trimming a first resistor (R1) of a scaling amplifier stage of the circuit. The trimming equalizes current flow through the differential amplifier stage and the scaling amplifier stage. The method includes: trimming a second resistor (R2) of the scaling amplifier stage to set an output voltage of the circuit to a target voltage at the first temperature; setting the circuit to a second temperature; and trimming a second resistor (R.sub.PTAT) of the differential amplifier stage, a third resistor (R1.sub.PTAT) of the scaling amplifier stage, and a fourth resistor (R2.sub.PTAT) of the scaling amplifier stage to set the output voltage of the circuit to the target voltage at the second temperature.

In an example method of trimming a voltage reference circuit, the method includes: setting the circuit to a first temperature; trimming a first resistor (R.sub.DEGEN) of a differential amplifier stage of the circuit; and trimming a first resistor (R1) of a scaling amplifier stage of the circuit. The trimming equalizes current flow through the differential amplifier stage and the scaling amplifier stage. The method includes: trimming a second resistor (R2) of the scaling amplifier stage to set an output voltage of the circuit to a target voltage at the first temperature; setting the circuit to a second temperature; and trimming a second resistor (R.sub.PTAT) of the differential amplifier stage, a third resistor (R1.sub.PTAT) of the scaling amplifier stage, and a fourth resistor (R2.sub.PTAT) of the scaling amplifier stage to set the output voltage of the circuit to the target voltage at the second temperature.

A control system for controlling an adjustable output voltage provided to a heater includes a controller configured to determine an input parameter based on an electrical characteristic of the heater, where the heater includes a resistive heating element that is operable to emit heat and as a sensor. The controller is further configured to determine an output voltage for the heater based on the input parameter and a desired setpoint, and to transmit a signal to a power converter to generate the output voltage. The desired setpoint is based on an operational state of the heater, and the input parameter includes data indicative of a temperature of the resistive heating element that is determined based on the electrical characteristic.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to measure a signal therefrom. The measured signal from the third coil is compared to a signal measured from the second coil and based on the results, internal CT parameters are determined allowing calibration of actual results to expected results thereby providing an improved accuracy. This is especially desirable when using the CT for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to measure a signal therefrom. The measured signal from the third coil is compared to a signal measured from the second coil and based on the results, internal CT parameters are determined allowing calibration of actual results to expected results thereby providing an improved accuracy. This is especially desirable when using the CT for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

Current sensing devices that are capable of surviving harsh ambient environment of ocean worlds, such as Jupiter and Saturn moons are disclosed. The described devices can meet 300 Krad radiation requirements and can survive at cold temperatures down to −184° C. Exemplary implementations of the constituent circuits of the devices are presented. A scheduling algorithm to perform various measurement by the disclosed current sensing devices is also described.

Current sensing devices that are capable of surviving harsh ambient environment of ocean worlds, such as Jupiter and Saturn moons are disclosed. The described devices can meet 300 Krad radiation requirements and can survive at cold temperatures down to −184° C. Exemplary implementations of the constituent circuits of the devices are presented. A scheduling algorithm to perform various measurement by the disclosed current sensing devices is also described.

A measurement circuit comprises an input terminal to receive a current signal, a first circuit branch coupled to the first terminal and including one or more circuit elements to receive a portion of the current signal, a second circuit branch coupled to the first terminal and including one or more additional circuit elements to receive another portion of the current signal, a nonlinear circuit element coupling the first circuit branch to the second circuit branch, and a quantization circuit configured to produce an input current measurement of current in the first and second circuit branches, and to include current in the second circuit branch in the input current measurement according to a magnitude of the input current signal.

A measurement circuit comprises an input terminal to receive a current signal, a first circuit branch coupled to the first terminal and including one or more circuit elements to receive a portion of the current signal, a second circuit branch coupled to the first terminal and including one or more additional circuit elements to receive another portion of the current signal, a nonlinear circuit element coupling the first circuit branch to the second circuit branch, and a quantization circuit configured to produce an input current measurement of current in the first and second circuit branches, and to include current in the second circuit branch in the input current measurement according to a magnitude of the input current signal.

In an embodiment, a current sensor unit includes: a rectification module, to convert an AC current to a pulsed DC current; a conversion module containing an energy storage element, to store energy based upon the pulsed DC current during a charging mode and to generate a power supply current based upon a voltage of the energy storage element; a mode switching module, bypassed by the conversion module during operation in the charging mode, and bypassing the conversion module during operation in an energy release mode; a current sensor module, to detect a pulsed DC current flowing back from the conversion module or mode switching module; a control module, to acquire electrical energy from the power supply current, determine that operation is in the charging mode or energy release mode based upon the voltage of the energy storage element, and acquire a detection value provided by the current sensor module.