A current-sense transformer (also known as a current transformer or CT) is a device used to measure electrical current. It works by using a magnetic core to transfer a portion of the current flowing through a conductor to a secondary winding, which is connected to a measuring instrument. Here's how it works in more detail:
The current to be measured flows through the primary winding of the current-sense transformer. The primary winding is usually a single turn or a few turns of heavy-gauge wire that encircles the conductor carrying the current.
The magnetic field created by the current in the primary winding induces a proportional voltage in the secondary winding of the transformer. The secondary winding is typically a large number of turns of fine-gauge wire wound around the same magnetic core as the primary winding.
The voltage induced in the secondary winding is proportional to the current flowing through the primary winding. The ratio of the number of turns in the secondary winding to the number of turns in the primary winding determines the degree of current reduction or amplification.
The output voltage from the secondary winding is typically very small, so it is amplified by an electronic circuit before being displayed on a measuring instrument, such as a digital multimeter or an oscilloscope.
Current-sense transformers are commonly used in power distribution systems, motor control applications, and electronic circuit protection to measure high currents accurately and safely without requiring direct electrical contact with the current-carrying conductor.
