What is the primary function of a ballast in lighting systems?

The primary function of a ballast in lighting systems is to aid starting and limit current flow. Ballasts are essential components in fluorescent and some types of HID lighting systems. When a light is turned on, the ballast provides the initial surge of voltage needed to ignite the lamp. Once the lamp is lit, the ballast regulates the electrical current flowing through the lamp, preventing it from drawing excessive current and causing damage or failure. This functionality helps ensure the lamp operates efficiently and improves its longevity.

The other choices do not accurately reflect the role of the ballast. While brightness might be a concern in lighting, the ballast itself does not increase brightness; rather, it manages the energy supply critical for the lamp to function correctly. Reducing energy consumption is more about the design of the lamp and the efficiency of the entire lighting system, rather than a direct function of the ballast. Similarly, changing the color temperature pertains to the type of lamp used rather than the function of a ballast.