| 摘要 |
A current sensor for detecting AC current through a load impedance of an electrical circuit. Sensor components are fabricated within a multilayer board so that a board can be made to comprise a plurality of independent sensors. The sensor includes a transformer circuit including a primary coil which is electrically coupled in series with the current path of the electrical circuit. This primary coil includes at least one current path element, in the form of a conductive strip constructed so as to add minimal resistance and inductance to the electrical circuit. The transformer secondary comprises at least a first electrically conductive coil inductively coupled to at least a part of the current path, and preferably a second electrically conductive coil inductively coupled to a second part of current path of the electrical circuit. The secondary coils are electrically connected in series with one another, so that voltages generated across the coils in response to current in the current path are additive, while interference voltages which are induced in the coils by the presence of uniform external magnetic fields or cross talk between adjacent sensors on the same board (where multiple sensors are provided) are cancelled.
|
