Current measuring device for measuring the electrical current flowing in an electrical conductor electrically isolated from the current measuring device

摘要

A current measurement device is configured to measure electrical current in a primary conductor that is electrically insulated from the current measuring device. The current measuring device includes a transformer with a saturable magnetic core formed with a central aperture and a current measuring circuit. The electrical conductor in which electrical current is to be measured is disposed in the central aperture of the magnetic core. The current measuring circuit includes a current source driven by a voltage ramp generator that is connected to the secondary winding in a direction opposite the flow of electrical current in the primary conductor. When the magnetic flux in the transformer core is equal and opposite the magnetic flux generated as a result of the electrical current flowing in the primary conductor, the voltage of the voltage ramp generator is representative of the DC or AC electrical current flowing in the primary conductor.