Bulb Lives Matter

Although they may look alike, they aren't. High-Intensity Discharge (HID) bulbs are a family of lamps that includes mercury, metal halide and high pressure sodium as the most popular. A few other related discharge-type bulbs are also included in this category: low pressure sodium, glow lamps and some pulsed arc bulbs.

HID bulbs produce light from an electrical arc discharge contained in an arc tube inside the bulb itself. The arc tube contains a gas mixture of argon and/or xenon and/or neon depending on the type of HID bulb. There are also metals inside the arc tube. Mercury vapor lamps produce light by exciting mercury atoms. Likewise, high pressure sodium excites sodium atoms. Metal halide, the most common of the HID bulbs, uses sodium and other halide compounds as the basis for exciting atoms to produce light.

Like fluorescent lights, HID also requires ballasts, and they take a few seconds to produce light when first turned on because the ballast needs time to establish the electric arc.

The purpose of the HID ballast is to regulate the voltage and current that are provided to the bulb during startup and under normal operating conditions. Each type of lamp requires a specific set of starting and operating parameters.

It is very important to match bulbs with the proper ballast system.  Each lamp has its own requirements. One ballast system will not operate all types of bulbs properly. A ballast cannot be manufactured to match all the requirements. If the bulb requirements are not met  (like using a bulb not designed for that ballast) less light output and/or shortened life or other problems could occur.