The magnetic ballast method creates a huge amount of inductive reactive power, significantly exceeding the magnitude of active power, but this reactive power can easily and cheaply be compensated without risk of any interferences, if done adequately.
The electronic ballast does not – or should not – produce substantial amounts of fundamental reactive power (displacement power factor DPF or cosφ). It need not but may be designed to operate on different mains frequencies, including DC, and different voltages, thereby also compensating any input voltage variances.
The decisive argument put forward for its use is, however, the energy saving achieved, not so much by lower internal losses in the ballast itself, but rather by an efficiency improvement of the lamp when operated at the high frequency supplied
from the output terminals of such electronic ballast.
For this reason they feed less power into the lamp than a magnetic ballast does. However, electronic ballasts are several times more expensive than the plain passive magnetic models and much more susceptible to certain disturbances and are likely to become themselves a source of disturbances.lighting fixture E27 lamp holder manufacturer.
magnetic ballast limit the flow of current to the light but do not change the frequency of the input power. The lamp then illuminates on each half-cycle of the power source. This is why many fluorescent and neon lights visibly flicker. Since the light illuminates on half-cycles, the rate of flicker is twice the frequency of the power source, meaning the light will flicker at 100Hz or 120Hz.
A lead-lag electronic lighting ballast can minimize flicker when connected to two lamps by alternating the flow of current to them: one leading the frequency of the input power and the other lagging behind it.
A more modern type of lighting ballast is electronic instead of magnetic ballast. An electronic lighting ballast uses solid state circuitry to transform voltage, but unlike magnetic ballast, can also alter the frequency of power. This means that an electronic lighting ballast can greatly reduce or eliminate any flicker in the lamps. Because it uses solid-state circuitry instead of magnetic coils, it is also more efficient and therefore runs cooler.
Because of their greater efficiency and ability to reduce flicker, electronic ballasts are more popular than magnetic ballast, and are often used to replace them. A few applications, however, require an magnetic ballast, such as ballasts that must preheat or ballasts for extremely high output lamps.
Magnetic Ballast to Electronic Ballast, The two timetables that govern the phased withdrawal of ballasts from the market that do not meet the new BEF standards are shown ,It”s important to note that both rules exempt American standard ballasts that are designed for:
Magnetic Ballast to Electronic Ballast, Dimming to 50% or less of maximum light output,
Use with two F96T12HO lamps at ambient temperatures of -20°F and marked for use in outdoor signs, and Labeled for use only in residential applications and operating with a power factor of less than 0.90.
Replacement magnetic ballast. These ballasts will feature output leads shorter than the length of the lamp they operate, may be shipped in packages limited to 10 or fewer units, and will be marked.