In this note, we are going to learn about Halogen Bulb and Its different parts, working, and applications. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.
Author Name: Arun Paul.
What is a Halogen Bulb?
A halogen bulb works on the same concept as a typical incandescent bulb, by transferring electric current through a tungsten filament to produce light. However, it contains a trace quantity of halogen gas (e.g., iodine or bromine), which reacts chemically with tungsten vapor.
This chemical reaction helps redeposit tungsten back onto the filament, preventing blackening and increasing the bulb’s life. This process is referred to as the halogen cycle.
Main Parts of a Halogen Bulb and Their Function
A halogen bulb is made up of several fundamental components that work together to emit light efficiently. The following are the important components –
- Antiglare Cap
- Prevents light from directly dazzling oncoming drivers.
- Controls light direction for safer visibility.
- Shell
- Holds and supports all internal components.
- Provides structure and stability to the bulb.
- Quartz Glass
- Encases the filament and halogen gas.
- Withstands high temperature and pressure, maintaining durability.
- Filament for High Beam
- Produces intense, long-distance light.
- Used in high-beam settings for highway driving.
- Filament for Low Beam
- Produces a softer, downward-focused light.
- Used in low-beam mode for city or short-distance driving.
- Bulb Base
- Fits into the socket and provides electrical contact.
- Ensures the bulb stays firmly in place.
- Stainless Steel Terminals
- Carry electric current to the filaments.
- Enable the bulb to glow when powered.
Working Principle of Halogen Bulbs
When energy passes through the tungsten filament, it heats up to around 2500°C – 3000°C, resulting in visible light. As the tungsten evaporates, halogen gas interacts with the particles and redeposits them onto the filament rather than settling on the glass’s inner surface.
This constant recycling process ensures that the bulb remains clean and brilliant over time.
Each component of a halogen bulb works together to produce bright, long-lasting, and reliable light. The halogen bulb, with its antiglare cover that prevents glare and filaments that produce both high and low beams, is a vital lighting component in automobile and spotlight applications.
Applications of Halogen Bulbs
There are many applications of halogen bulb but here we have listed 5 top applications of this bulb –
- Automotive headlights and fog lamps
- Stage and studio lighting
- Outdoor floodlights
- Residential spotlights and desk lamps
- Projectors and display lighting