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

MH lamps use probe-start, magnetic ballast technology, which employs the use of two operating electrodes and a third, starting probe electrode in the arc tube.

Three electrodes are present in the arc tube of a probe-start MH lamp: a starting probe electrode and two operating electrodes . To start the lamp, a discharge is created across a small gap between the starting probe electrode (also called the starter electrode) and the operating electrode. Electrons then jump across the arc tube to the other operating electrode to help start the lamp. Once the lamp is started, a bi-metal switch removes the starting probe electrode from the circuit.