Abstract: A single-package power meter is disclosed for measuring the power consumed by a load connected to an electrical conductor. The power meter is galvanically isolated from the electrical conductor through the use of magnetic sensors or through the combination of magnetic sensors and capacitors. Instantaneous power consumed at the load and other desired parameters are determined by measuring the voltage of the load and current flowing through the electrical conductor. Current is measured using a magnetic sensor to detect the magnetic field associated with the current flowing through the electrical conductor. Voltage is measured by one of two possible techniques involving magnetic sensors to measure the current flowing through a coil connected in parallel with a load, or through the use of a capacitively coupled voltage divider connected in parallel with the load.

Abstract: A transducer is disclosed for detecting the AC and DC voltage difference between two nodes in an electrical circuit and electronically transmitting the measured voltage difference to an electrical system that is electrically isolated from the common mode potential of the two nodes. The voltage drop between two points in a circuit under test is determined by detecting the current flowing through a resistive shunt coil connected in parallel to the test points. Current through the resistive shunt coil is linearly proportional to the voltage difference between the test points, and it is detected by using a magnetic sensor that is separated from the shunt coil by an insulating dielectric barrier. The transducer can be packaged in a standard integrated circuit package in order to provide a small and low cost voltage transducer for test, measurement, control, and signal-isolation applications.