Apparatus for fast measurements of current and power with scaleable

Abstract

A device for non-contact, non-invasive measurement of current or power in a wire, cable or conductor includes a small coil having multiple turns and no ferromagnetic core. The coil may be secured to a wand or housing adapted to be used to place the coil in close proximity to the wire, cable or conductor, whereby a voltage is induced in the coil. An amplifier may be utilized to increase sensitivity. A readout indicates the magnitude of the induced voltage, and a scaling device renders the readout display indicative of the current or power in the wire, cable, or conductor. To measure direct current flow, the coil may be vibrated or rotated adjacent to the conductor to cause the magnetic field to induce a voltage in the coil. The readout may comprise a digital display, a series of light emitting devices, or a flashing light emitting device having a flash rate proportional to the magnitude of the voltage. The device may be constructed in a wand or pen-like fashion, with the coil incorporated into the wand. The device may be combined with a voltage sensor.