Understand why transformers only operate with AC and not DC. Learn about electromagnetic induction, the need for a changing magnetic field, and how DC can cause core saturation and damage transformers. Get insights into the science behind transformers and why AC is essential for their function.
Transformers rely on the principle of electromagnetic induction to operate. This principle states that a changing magnetic field induces an electromotive force (EMF) in a conductor.
Here's why transformers only work with AC:
-
Changing Magnetic Field:
- AC: When an alternating current flows through the primary coil of a transformer, it creates a continuously changing magnetic field around the coil. This changing magnetic field is essential for inducing an EMF in the secondary coil.
- DC: In a direct current circuit, the current flow remains constant. This results in a constant magnetic field around the primary coil. A constant magnetic field does not induce an EMF in the secondary coil, as there is no change in the magnetic flux.
-
Mutual Induction:
- AC: The changing magnetic field produced by the AC current in the primary coil cuts through the secondary coil, inducing an EMF in it. This process is known as mutual induction.
- DC: Since there is no change in the magnetic field with DC, mutual induction cannot occur, and no EMF is induced in the secondary coil.
In essence, transformers require a changing magnetic field to function. AC provides this necessary changing magnetic field, while DC does not. Therefore, transformers only work with AC power.
