What is Electromagnetic Ballast? – Operation, Advantages, Disadvantages | New Topic [2024]

In this note, we are going to learn about a topic called “What is Electromagnetic Ballast?“, and also about its operation, advantages, and disadvantages as well. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

What is Electromagnetic Ballast?

An Electromagnetic Ballast, also known as a magnetic ballast, is an electrical device that limits current in electrical circuits, particularly in gas discharge lamps such as fluorescent, metal halide, and high-pressure sodium lamps. It is one of the earliest forms of ballasts and functions on the basis of electromagnetic induction.

Operation of Electromagnetic Ballast

The ballast consists of a wire coil wound around an iron core. When alternating current (AC) from the mains flows through the coil, it generates a magnetic field. This magnetic field creates inductive resistance, which limits the amount of current that may travel through the circuit. This current-limiting function is critical for gas-discharge lamps because they have negative resistance characteristics—if the arc is started without a ballast, the current would build uncontrollably, potentially ruining the lamp.

The electromagnetic ballast initially generates a high starting voltage, which ionizes the gas inside the lamp and creates a conducting route. After the arc is formed, the ballast drops the voltage and controls the current to a steady level that allows the lamp to operate without overheating or overload.

Advantages of Electro magnetic Ballast

Below we have listed some merits of this device –

• It is Simple and inexpensive.
• It has long life span.

Disadvantages of Electromagnetic Ballast

Below we have listed some demerits of this device –

• This is bulky and heavy.
• It consumes additional power.
• It is generate more heat.