Analog Devices International Unlimited Company

Analog Devices Global

Shaoli Ye

William Michael James Holland

John Jude O'Donnell

Gina M Kelso

David J Lath

Jonathan Ephraim David Hurwitz

Seyed Amir Ali Danesh

William Holland

John O Donnell

Gina Kelso

David Lath

The disclosure relates to accurately determining a DC energy signal, such as a DC current or DC voltage, which may be particularly useful when controlling a formation/testing current of a battery cell during formation and/or testing. In the battery formation/testing context, a current sensor is used to measure the current of the battery cell, which is used as a feedback signal for controlling the current to achieve a target current. The transfer function of the current sensor is used to improve the accuracy of the current measurement. Because the transfer function can be regularly determined during formation/testing, a lower-cost current sensor with relatively poor temperature coefficient may be used. Any change in the gain of the current sensor may be detected by the transfer function determination and corrected for. Therefore, high current control accuracy may be achieved at lower cost.

DC signal measurement and battery formation/testing

Techniques for controlling a current of a battery cell during formation and/or testing are described. A current sensor is used to measure the current of the battery cell, which is used as a feedback signal for controlling the current to achieve a target current. The transfer function of the current sensor is used to improve the accuracy of the current measurement. Because the transfer function can be regularly determined during formation/testing, a lower-cost current sensor with relatively poor temperature coefficient may be used. Any change in the gain of the current sensor may be detected by the transfer function determination and corrected for. Therefore, high current control accuracy may be achieved at lower cost.

Battery formation/testing

Current transducers are widely used in current measuring systems. They provide good isolation between the supply voltage and the measurement equipment. However they can introduce small phase errors which can become significant sources of error if the current to a load is out of phase with the supply voltage for the load. This disclosure discusses a robust measurement apparatus and method that can be used in situ to monitor for and correct phase errors.

Method of and apparatus for learning the phase error or timing delays within a current transducer and power measurement apparatus including current transducer error correction

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Woburn, MA, United States of America

Shaoli Ye