Magnetic ballast is an essential component in traditional discharge lamps and tubes. In order to properly start them, an initial high current is needed which needs to be limited afterwards to prevent the lamp from blowing out. This function is performed by ballast. Electro-magnetic ballasts were one of the first components that could provide sufficient starting current to fluorescent lights or low pressure tanning lamps. Although they are being replaced by much lighter and efficient, electronic ballasts, electro-magnetic ballasts are still in trend. This article will explore the structural features of the ballast and it’s working.Numerous manufacturers are producing their own customized versions of Magnetic ballasts. Depending upon the brands, size and the power requirements, ballasts can be of various types. The casing is made of Aluminum and has the specifications featured over it. On its side are two connecting plugs which connect the ballast to the fluorescent light.