22 Fluorescent Lamps: Induction Lamps

Induction lighting was introduced in the 1990’s, and although it is one of the best technologies developed in recent years, many distributors in the lighting industry are still not familiar with this product. The basic technology used in induction lighting relies on the fundamental principles of gas discharge and electromagnetic induction to produce light.

Compared to the classic fluorescent lamp, the induction lamp has many advantages, such as having no direct electrical connection to an external circuit, meaning there are no filaments or cathodes to breakdown and fail. This results in this lamp having an unmatched lifespan of 100,000 hours or around 25 years in service. Because this system can last longer than one-hundred incandescent lamps or five typical fluorescent lamp changes, it is ideal for installation in hard to reach areas such as airports, railroads and highway signs, roadway lighting and hazardous locations where frequent lamp replacement would be impractical.

Induction lighting systems are very reliable, and have an instant strike-up and restrike time, while producing no noise or stroboscopic effect when in use.

The main disadvantage of induction lighting is its high initial installation cost, which is presently higher than traditional fluorescent lighting systems. They have a typical efficacy around 70 lumens per watt and a good CRI rating of around 80.

The ballast is an electronically controlled high-frequency generator, and supplies the energy through a power coupler to a primary induction coil, either inside the induction lamp, or clamped around a section of the lamp. The secondary coil of the induction system is represented by the low-pressure gas and metal mercury vapour inside the lamp.

The induction lamp relies on the fundamental principles of gas discharge and electromagnetic induction to produce light. The electronic ballast produces a high frequency oscillating magnetic field which passes through the gas of the fluorescent lamp. Induction lamps produce light in the same two stages as the fluorescent lamp, with the magnetic field inducing a secondary charge inside the lamp. The induced current causes the acceleration of charged particles in the metal mercury vapour causing collisions between moving electrons and mercury atoms. The gas is thus excited to the point where it produces UV radiation, which then collides with the phosphor coating on the bulb and is then converted into visible light.