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.