A magnetic device for high-speed sensing of small currents

A magnetic device, capable of sensing small currents, has been developed. A bar or stick of low-coercive-force square-loop ferrite forms the core of the device, and two holes pierce the stick, transverse to its long axis. The current to be detected flows in a solenoid, which surrounds the stick. The sensing of this current is accomplished by observing the flux switched around the holes under the action of a pulse of current flowing through them.