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

The constant wattage autotransformer HID ballast type should be used where a stabilized light output is required. CWA is an HID ballast type that comes in a fairly small economical size, yet still provides a reasonable degree of regulation. It also offers the advantage of a high power factor, low line extinguishing voltage, and line starting currents that are lower than operating currents,Magnetic ballast use a coil wrapped around a metal core, essentially an electromagnet, to generate an inductive field that affects the voltage flowing through the coil wire. Because they work at a lower cycle than electronic ballasts, you may notice a flicker or hear a hum coming from fixtures containing electromagnetic ballasts. Prior to 1980, the dielectric fluid and potting material in magnetic ballasts contained polychlorinated biphenyls (PCBs), a highly regulated, highly toxic carcinogen. Congress banned the manufacture of PCBs in 1977 and banned their use in 1979 in all but totally enclosed equipment. From 1979 through 1991, Di (2-ethylhexyl) phthalate (DEHP), another toxic hazardous material, was used to replace PCBs in certain ballast capacitors. 

Unlike the high power factor auto-transformer (HX-HPF), which uses a capacitor as a parallel component, the capacitor on a CWA ballast type is used in series with the lamp. This provides the lamp with a more stable wattage when voltage on the branch circuit fluctuates. 

The capacitor is referred to as a lead circuit when, as in the case of the CWA ballast, it performs an important ballasting function.