A low-noise alternating current sensor enables low-cost, large dynamic range current measurements of low-frequency alternating current flows. The low-noise current sensor offers enhanced dynamic range and fine-grained sensitivity unavailable in existing sensor technology. The sensor's dynamic range and sensitivity to low-frequency AC enable new capabilities in precision current control: a valuable and necessary capability in the control and management of circuit considerations, from applications for the grid to transportation, to the control of remote assets.