Current sensor

摘要

An apparatus and method make use of a single shunt and two or more instrumentation amplifiers, switchably measuring voltages at the shunt. This permits current measurement. At times each instrumentation amplifier has its input shorted, which permits zeroing out many sources of offset in the signal path of that amplifier. Dynamic range is several orders of magnitude better than known current measurement approaches, permitting coulometry.

主权项

1. Apparatus for use in measuring current with respect to first and second measurement points, the apparatus comprising:
a first instrumentation amplifier, said instrumentation amplifier having first and second input terminals, a first impedance means connecting the first and second measurement points to first and second terminals of a first switch, respectively, with the first and second terminals of the first switch connected respectively to the first and second input terminals of the first instrumentation amplifier; a second instrumentation amplifier, said instrumentation amplifier having first and second input terminals, a second impedance means connecting the first and second measurement points to first and second terminals of a second switch, respectively, with the first and second terminals of the second switch connected respectively to the first and second input terminals of the second instrumentation amplifier.