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

Traditional HID ballasts use magnetic coils to regulate current and voltage to provide proper lamp starting and operation. These magnetic ballasts tend to be hot, bulky and heavy, which affects their suitability for some applications.

Electronic ballasts are available for HID lighting systems. These ballasts provide the same functions as their magnetic counterparts but use power-supply switching electronics rather than magnetic transformers to operate the lamp. This results in reduced energy losses and improved operating characteristics (see insert).

Electronic ballasts have been successfully used with fluorescent lighting systems for many years, largely because of their improved energy performance and dimming capabilities. Electronic ballasts for HID lighting systems have become available only more recently. Initially, electronic HID ballasts were primarily for use with lamps of 175 W or less. But reliable electronic ballasts are now becoming available for use with higher wattages of 150, 250, 400 and even up to 1000 for metal halide and high-pressure sodium HID lighting systems.

Noise. Magnetic ballast produce noise because the metal laminations within them vibrate as the magnetic field changes at the line frequency of 60 times per second. Electronic ballast products are available that operate at both high and low frequencies, but operation is silent because the ballasts don’t have laminations to vibrate. This quality is important in areas such as libraries, concert halls, and retail shops.

Light flicker. Some electronic ballasts for metal halide lamps operate at much higher frequencies than the 60 hertz (Hz) of magnetic ballasts. This high-frequency operation eliminates the flicker that can accompany line-frequency operation and can cause headaches or otherwise affect a room’s occupants. High-frequency electronic ballasts also eliminate the stroboscopic effect. Although other types of lamp flicker are just annoying, the stroboscopic effect can be dangerous. When circular saws, drill presses, and other machinery operate at a certain speed, the stroboscopic effect from magnetic ballasts can cause the machines to appear as if they are not operating. Other electronic ballasts operate at lower frequencies (75 Hz for one product), but they have a square wave design that also eliminates flicker.

Longer lamp life. Ballast manufacturers report that pulse-start metal halide lamp life may be increased by about 25 percent through the use of electronic ballasts. This effect is plausible, because electronic ballasts provide more-precise control of current and therefore place less stress on electrodes when a lamp is started. But as of yet, no independent confirmations of increased lamp life have been made, and it may take some time for manufacturers to verify longer lamp life. Meanwhile, when trying to estimate the life of a lamp operating with a particular electronic ballast, use data from a lamp manufacturer rather than from a ballast manufacturer.