If you are wondering just how a fluorescent light produces visible light, here is the basic principle: The light is created by a process that energizes a gas which is confined within the bulb. This causes the gas to emit radiation, which hits the coating on the bulb and thus creates light. The process is swift and the electrical current must be controlled, and this is where the ballast plays its role.
The role of the ballast is crucial to the process of producing light, as it limits and carefully times the electrical current before it flows into the bulb. Without the ballast, the current will spiral out of control and render the bulb inoperable. Ballasts come in two different types; the first one is magnetic and uses simple electromagnetic generator, whereas the second is electronic and requires more sophisticated circuitry.
The magnetic ballast was created first and as such is much simpler than its electronic counterpart. It consists of the steel core and several capacitors, while the electronic ballast consists of a mixture of electronic filters and transformers to control the flow of the current. Electronic versions are much more complicated, but also lighter and more convenient for use in small spaces.
Magnetic ballasts were primarily made to provide the traditional fluorescent lights and usually come in the shape of long tube. With the invention of more sophisticated fluorescent bulbs, such as dimming bulbs with multiple sockets, the magnetic ballast could no longer keep up with modern times and supply electricity to the new age bulbs, which is the area where electronic bulbs thrives in.
Magnetic ballasts only work well for providing basic fluorescent light because it limits electrical current to 60 hertz. This property slows the current down to the point that it creates a flicker, which is often noticeable in the light. As opposed to magnetic ballast, the electronic versions operate at 120 hertz which makes flickers invisible for human eye to register.
Given the simplicity of magnetic ballasts, they are quite easy to manufacture. Because of this, they come at a considerably lower cost than their electronic cousins, which are more expensive.