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

When the switch is closed circuit 220V50Hz AC power is applied, the current flowing through the high pressure sodium ballast, lamp filament to filament heating ignitor(ignitor is disconnected from the beginning, due to the application of an AC voltage greater than 180V so jump ignitor arc discharge gas inside the bubble, jump vesicles bimetal thermal expansion deformation, two electrodes close together to form a pathway to the filament heating). When the starter of the two electrodes close together, because there is no arc discharge, the bimetal cooling, disconnect the two electrodes, the core ballast is inductive, the moment when the two electrodes is disconnected, the circuit current suddenly disappeared, so ballast generates a high pulse voltage, the power supply voltage is superimposed upon it, added to the tube ends, so that the lamp inside the inert gas ionization caused by arc discharge. (High pulse voltage time of about 1ms 600V ~ 1500V, its exact value depends on the type of lamp voltage). In the course of normal light, a stabilizing ballast inductance current in the circuit. Ballast is an iron core coil, when the nature of the inductor current in the coil changes, the magnetic flux induced in the coil will change, thus generating induced electromotive force in a direction opposite to the direction of the current, thereby preventing current changes, and thus play a role in stabilizing current limiting