In many industrial settings, the current metering transformer is an important part of the control circuits. It has the ability to monitor and sense current levels and to keep components safe. However, some equipment utilizes hall effect sensors, and they are different from the current transformer (CT) applications. Here is a closer look at each component, to give you a better understanding of the differences.
Current Transformers
In many control circuits, potential transformers take in high voltages and lower them so they can be used by lower voltage applications like motor control circuits. A current metering transformer is different because it can lower electrical current. Instead of two large coils of wire, the primary windings may consist of one coil or a buss bar. The secondary current is always proportional to the primary.
A current metering transformer can detect both undercurrent and overcurrent conditions to keep circuits and components safe from damage. CTs are often used in high-voltage situations and power transmission systems, too.
Hall Effect
When electrical current is flowing through a conductive medium (like a metal bar) while influenced by a magnetic field, the moving electrons (charge carriers) get forced to one side of the conductor. In other words, the normal path electricity takes through the conductor is altered by the magnetic field. Each side of the conductor generates voltage, which can be measured. The presence of this transverse electric field is called the Hall Effect. It was first noticed in the late Nineteenth Century by E.H. Hall.
What is the Difference?
Hall Effect items are used for detecting position. For example, a crankshaft position sensor knows when the pistons are in the proper position. They can also be used as speed sensors. A current metering transformer does not detect proximity. Instead, it is used for monitoring current and keeping circuits from damage.
