TCP 40 Watt Screw-in Circline Ballast

Magnetic ballasts are a legacy technology and use inductance to transform the line voltage to the voltage required to "fire" or excite the gasses in a lamp. Electronic ballasts use a variety of starting methods, and are more efficient than magnetic ballasts in converting input power to the proper lamp power and operate fluorescent lamps at higher frequencies, resulting in an overall lamp-ballast system – increasing efficacy 15% to 20% over a magnetic equivalent.

For Ballasts, indicates the method the ballast uses to start its bulbs. HID ballasts can be Probe or Pulse start. Fluorescent ballasts can be Rapid, Instant or Programmed start. For HID and Fluorescent bulbs, indicates the start-type of ballast that the bulb will work with.