Abstract: A snubbing network is provided for reducing electromagnetic ("EM") radiation from and power dissipation of a lamp discharge ballast. The snubbing network employs at least one active device. That device being a switch coupled in parallel with the modulating switch within a converter of the ballast. The snubbing switch, in conjunction with a current limiting inductor, and a voltage change rate limiting capacitor serve to substantially eliminate reverse recovery current within a freewheeling diode of the converter prior to closing the larger (modulating) switch. Reducing the reverse recovery current before closing the modulating switch helps minimize power dissipation during switch closure. A benefit of reduced power dissipation is a reduction in EM radiation from the lamp ballast to noise sensitive electronic components placed nearby.

Abstract: A gas discharge lamp is provided having a ballast control element and suppressible igniter. The igniter is chosen to superimpose an ignition pulse onto the initial AC ballast cycle or cycles provided to the lamp. The secondary coil of the igniter transformer is initially shorted until sufficient voltage is applied to the igniter. This causes a switch arranged across the secondary coil to open. A voltage detector coupled to a primary winding of the igniter transformer senses the amount of voltage applied from the ballast. Once that amount has been detected, the secondary winding is no longer shorted and the igniter can initially ignite the lamp during a peak of the initial cycle or cycles from the ballast. After the lamp has been initially ionized/discharged, or after a pre-defined set of discharges, the switch remains closed for the duration of each and every ballast cycle. Thus, the igniter is suppressed from the ballast output, and the ballast alone provides lamp discharge.