A magnetic ballast is a device that uses a magnetic field to limit the electrical current supplied to a lamp, an older technology that generally does not prevent flicker.
A magnetic ballast regulates the current flowing to a discharge lamp by using the inductive effect of a coil wound on a magnetic core. This current limiting is necessary because many lamp types would otherwise draw excessive current. Magnetic ballasts represent an earlier generation of the technology and generally allow some visible flicker because they operate at the frequency of the supply.
In commercial and industrial lighting, magnetic ballasts have largely been succeeded by electronic ballasts and integrated drivers that offer smoother operation and improved efficiency. Where magnetic ballasts remain, the lighting circuits feeding them rely on appropriately rated power and control wiring. Understanding the ballast type helps in interpreting how a lighting system behaves and what its supporting wiring must accommodate.
Because the behavior of a lighting circuit depends on the device controlling it, identifying whether a fixture uses a magnetic or an electronic control changes what to expect in terms of flicker and efficiency, and it clarifies the demands placed on the power wiring that feeds the fixture during normal operation.
Knowing the control type also clarifies what an upgrade involves, since moving away from magnetic technology changes both the efficiency of a lighting system and the way it behaves on the circuit feeding it.
At Windy City Wire, the focus on low-voltage power and control cable connects to lighting systems of all kinds, including those using ballasts. Supplying dependable cable for the circuits that serve lighting helps ensure stable, reliable operation regardless of the control technology a fixture employs.