Abstract: A device for measuring alternating current in a conductor comprising an even number of identical coils (C1) to (C14) mounted on an electrically insulating coil support member (10). Half the coils (C1) to (C7) are equally spaced around a first notional circle and are connected in series by a first conductive track (12) and the other half of the coils (C) to (C14) are equally spaced around a second notional circle, concentric with the first, and are connected in series by a second conductive track (14). The support member (10) has a recess (16) to allow a conductor under test to be introduced into the centre of the concentric circles. The device further includes means (R1, R2, 20) for deriving the alternating current in the conductor as a function of the voltages induced in the first and second sets of series-connected coils. The coils (C1) to (C14) and the support member are manufactured by printed circuit or thick film technology.

Abstract: A device for measuring alternating current in a conductor comprising an even number of identical coils (C1) to (C14) mounted on an electrically insulating coil support member (10). Half the coils (C1) to (C7) are equally spaced around a first notional circle and are connected in series by a first conductive track (12) and the other half of the coils (C) to (C14) are equally spaced around a second notional circle, concentric with the first, and are connected in series by a second conductive track (14). The support member (10) has a recess (16) to allow a conductor under test to be introduced into the centre of the concentric circles. The device further includes means (R1, R2, 20) for deriving the alternating current in the conductor as a function of the voltages induced in the first and second sets of series-connected coils. The coils (C1) to (C14) and the support member are manufactured by printed circuit or thick film technology.