China manufacturer of magnetic ballasts for metal halide flood lights & hps flood lights

The fluorescent ballasts are employed in light bulbs to control the flow of electricity from a power source to the light source. When a steady flow of electricity to the light bulb is disrupted, the bulb will flicker.
There are two types of ballasts used for lighting including electronic ballasts and magnetic ballasts. Magnetic ballasts are an older technology, fluorescent light bulbs that feature magnetic ballasts are much more likely to flicker than electronic ballasts.
Electromagnetic ballasts are designed to condition the 60 Hz input voltage to the electrical requirements of the lamps. A magnetic ballast alters the voltage, but not the frequency. Thus, the lamp voltage crosses zero 120 times each second, resulting in 120 Hz light output oscillations. This results in about 30% flicker for standard halophosphor lamps, operated at 60 Hz. The flicker is generally not noticeable but there is evidence that flicker of this magnitude can cause adverse effects, such as eyestrain and headache.

Most electronic ballasts, on the other hand, use high-frequency operation, which reduces lamp flicker to an essentially imperceptible level. The flicker percentage of a particular ballast is usually specified by the manufacturer. For a given ballast, the percent flicker will be a function of lamp type and phosphor composition.

If a compact fluorescent bulb is loosely fit in lamp socket, the bulb can flicker. If the mounting plate that the ballast is attached to is loose, the ballast can vibrate causing the bulb to flicker.Most fluorescent tubes flicker or swirl for up to 100 hours when brand-new. However, if a tube has been installed for some time, does not appear blackened at both ends (brown is normal) and one day develops a flicker, turn off the light and remove the tube by turning it a quarter turn and pulling it straight out. Inspect the pins at each end. If any appear bent, gently straighten them with needle-nosed pliers.