What is a HID ballast?

An HID ballast is a device that is designed to limit the electrical output of the particular circuit you have.  When you’re dealing with HID xenon lights you have an HID ballast.  The ballast is a normal electrical ballast but it has specifications that are set for use with an HID circuit.  A normal electrical ballast will not work with a HID xenon light bulb.

A HID ballast is special for a few reasons.  It enables better control over the output frequency.  It’s also important because the HID ballast has an inductor which provides a voltage spark when the circuit is completed that helps the arc for in the arc tube.

The arc is formed across an electrical gap between 2 electrodes inside the HID bulb.  When the HID ballast initiates it fires a spike of voltage that pushes the current across the gap then backs off and control the output very efficiently.