What was wrong with gas discharge lamps? Why were they discontinued?

Gas discharge lamps were pretty efficient. Sodium vapor lamp remains the most efficient artificial lighting source even to this day. But efficiency is not everything. And they did suffer a few problems

1. Even though conceptually simple,they were complicated to manufacture. The housing needed a way to handle materials in gas phase. Usually glass was used which is fragile to handle so many of these lighting devices had to be protected during their entire operation. The device required components such as ballasts to regulate energy flow. Compare this to LEDs that are shipped in plastic encapsulation and can be arranged in any pattern. Since it runs on dc it can be integrated with both portable devices that run on battery and in homes with mains voltage.

2. With the success of LED some of the semiconductor engineering technology that was used for manufacturing chips could now be used for LEDs . Today light is completely a semiconductor device and it benefits from any improvement that happens in semiconductor manufacturing. It is one of the primary reasons why such large volume of lights can be manufactured in a small time.

3. New usecases like integrated lighting and backlights for portable displays emerged that could not use bulky gas discharge lamps. These devices could only run on led. And success of these devices meant that LED carved out a new market for itself #blueocean

4. Light is not just used for illumination but also for communication. In communication industry signal modulation becomes very important to encode information on a carrier wave. Such modulation of light is not possible with gas discharge lamps which have considerable startup times as opposed to LEDs which have turn on time in nanoseconds https://electronics.stackexchange.com/questions/86717/what-is-the-latency-of-an-led

These are the factors :packaging,integration speed and efficiency which led to LEDs displacing other prominent forms of lighting including gas discharge lamps. Gas discharge lamps however continue to be used in applications that require high energy output. Like UV lamps for example. Any technology that goes mainstream can never truly be replaced. Gas discharge lamps are a proof of that.

#engineering #light

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Notes by Akshat Jiwan Sharma

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