from The Century Dictionary and Cyclopedia
- n. In electricity, a resistance placed, for purposes of regulation, in series with the filament of an electric lamp. In the case of the Nernst lamp the ballast consists of a very fine iron wire in an atmosphere of hydrogen within a sealed glass tube.
Sorry, no etymologies found.
This was due to the common dimensions of the T8 lamp and the simplicity of a lamp-ballast swap.