Many new manufacturers, both domestic and foreign, have entered the market. The ballast also may provide voltage to heat the lamp's electrodes to assist in lamp starting or lamp operation. Magnetic ballasts contain a magnetic core of several laminated steel plates wrapped with aluminum or copper windings. Such high-loss ballasts can no longer be sold in the United States. Cathode-disconnect ballasts are magnetic ballasts that do not provide voltage to heat the lamp electrodes during lamp operation.
Electronic ballasts regulate voltage using solid-state components rather than a magnetic core.
The manufacturers were also asked to submit three samples of each product for testing. Results Ballast factor. For the other 12 ballasts, ballast factor ranged from 0.81 to 0.92. Ballast factor for the six ballasts that operate two 8-ft T12 lamps ranged from 0.78 to 0.87. The three ballasts that operate two 8-ft T8 lamps had ballast factors that ranged from 0.81 to 0.99.