摘要 |
Methods and system for sensing current include detecting current through a sensing coil resulting from a field produced by current through a primary conductor. The sensing coil has a core that may become saturated by the primary current field. If the core is not saturated, a sensing circuit may detect the current through the sensing coil by changing the state of at least one controlled switch. If the core is saturated, the sensing circuit changes the state of the at least one controlled switch to pull the core out of saturation, at which time a current measurement is made. The technique may be used with AC currents, including changing currents, as well as with DC currents, and currents that may be AC at times and become essentially DC at other times. |