The simplest type of fluorescent lamp ballast, called a magnetic ballast, works like an inductor and generates a magnetic field when electric current is sent through a wire, according to HowStuffWorks. A basic inductor is composed of a coil of wire in a circuit, which can be wound around a piece of metal.Continue Reading
The field is amplified when the wire is positioned in concentric loops, states HowStuffWorks. This affects the objects around the loop as well as the loop itself. When the current in the loop is increased, the magnetic field is also increased, applying a voltage opposite the flow of current in the wire. This means that a coiled wire in a circuit opposes change in the current that flows through it. This principle is used to control the current in a fluorescent lamp.
HowStuffWorks notes that a ballast cannot stop changes in current. However, the alternating current that powers a fluorescent light constantly reverses itself, enabling the ballast to restrict increasing current in a specific direction for a short period. Magnetic ballasts are capable of modulating electrical current at a relatively low cycle rate, causing a conspicuous flicker. They can also vibrate at a low frequency, leading to an audible humming sound that people usually associate with fluorescent lamps.Learn more about Lighting
According to the Lighting Research Center, a ballast is an electrical component that limits the amount of current that can flow through a fluorescent light tube. Without a ballast, a fluorescent bulb would draw more and more current until it blew itself out. In commercial applications, fluorescent bulbs and ballasts are often two separate components, while consumer fluorescent lights, such as CFL bulbs, often combine the two units together.Full Answer >
To replace a fluorescent light ballast, take off the cover of the old ballast, cut out the wiring, unscrew the old ballast and attach the new ballast. Ballast replacement is a common solution to flickering or humming fluorescent lights.Full Answer >
LED is short for light-emitting diode and works by running an electrical current through a semiconductor material, typically aluminum-gallium-arsenide, into the junction of a diode. Phosphor is added to the diode to filter the light output and create a more pure color.Full Answer >
After shutting off the power to the fixture and removing the fluorescent bulbs, remove the ballast covering, and then test the ballast using a volt ohmmeter, which should show a continuous electrical current flowing through the device. If there is electrical current, look for other signs of damage to the fixture. If there is no current, replace the ballast.Full Answer >