would a ballast regulate current alone or EMF as a whole?

Answer 1

A ballast which is used primarily used in things like fluorescent or neon lights and even in automotive ignitions. It's used to compensate for a phenomenon called negative Resistance. When a voltage is passed across a light or the ignition, there is no current flow until a threshold. At the that threshold a correct flows and the voltage across the device and for a constant voltage, the current continues to increase. The ballast keeps the system from self destructing.

http://en.wikipedia.org/wiki/Ballast_(electrical)

http://en.wikipedia.org/wiki/Ballast_(electrical)