Current Transducers Current Transducers (CTs) ar a essential element of power observance. They come during a style of formats, sizes, current ratings and accuracy levels. The side we'd wish to concentrate on here is size, specifically inside diameter. The inside diameter (ID) is the width of the opening in the CT that the conductor goes through. It must be large enough to fit around the conductor, however choosing too large of a CT can create other issues. As the graphic above indicates, the overall dimensions of the CT grow substantially as the ID gets bigger. Current Transducer Types Current sensors can be either open-loop or closed-loop. Open-Loop Sensor: This type measures AC and DC currents and provides electrical isolation between the circuit being measured and the output of the sensor. Open-loop current sensors are generally preferred in battery-powered circuits. Closed-Loop Sensor: The Closed-Loop sensor is sometimes called a ’Zero-Flux’ sensor because i...