Hall current sensors, also commonly referred to as current transformers, are devices that detect current using magnetic fields and produce proportional outputs to measure the current flowing through a conductor. What are ultra-precision Hall current sensors? These sensors are used with both AC and DC currents. They allow for passive measurement of current without interrupting the circuit in any way. The sensors are placed around the conductor we want to measure.

Current transformers are essential in many applications. For example, they are often used for sub-metering to determine the energy usage of individual tenants. They can also help facility management by providing information on energy usage and timing, helping to reduce costs and increase efficiency.

How do Ultra-Precision Hall Current Sensors Work?

When current flows through a conductor, it creates a proportional magnetic field around it. Current transformers use this magnetic field to measure current. If a current transformer (CT) is designed to measure AC current, it typically uses induction technology. The alternating current changes potential, causing the magnetic field to continuously collapse and expand. In AC current sensors, wires are wound around a core. The magnetic field generated by the current through the conductor induces a proportional current or voltage in the wires within the current sensor. The sensor then outputs a certain voltage or current, which can be read by a meter connected to the sensor and converted into the amount of current flowing through the conductor. For instance, when the current through the conductor is 400A, a current transformer might have an output of 333mV (a common output for CTs). Once you configure the meter to read 400A when receiving a 333mV input, it will be able to calculate the amperage flowing through the conductor based on the input received. DC current sensors work similarly, but they rely on Hall effect technology, which is the basis for ultra-precision Hall current sensors.

Current transformers can step up, step down, or maintain current levels. Sensors that step up or step down current are typically called transformers. These sensors usually consist of two coils. The coil through which current flows is called the primary winding, while the coil that induces voltage is called the secondary winding. For many current transformers sold on vicorv.com, the conductor with the installed CT serves as the primary winding, and the secondary winding is located inside the transformer. The magnetic core around the secondary winding depends on the sensor's design and handling. The turns ratio of a transformer is the number of turns on the secondary winding divided by the number of turns on the primary winding. This ratio determines whether the transformer increases or decreases voltage. The ratio of secondary voltage to primary voltage is equal to the turns ratio, as shown by the equation. Therefore, when the number of turns on the secondary winding is greater than that on the primary winding, the voltage on the secondary winding is higher, making it a step-up transformer. Conversely, for current, the ratio of secondary current to primary current is equal to the inverse of the turns ratio.