Abstract: The circuit comprises a switched dc/dc converter of the "fly-back" type, a second switched dc/dc converter of the "feed-forward" type, an H-shaped bridge switching circuit which is connected to the dc/dc converters and in the central branch of which the discharge lamp and an associated reactive starter device are disposed, and a control circuit which can drive the dc/dc converters and the bridge switching circuit in a manner such that, each time the lamp is switched on, a very high voltage is applied initially, in particular, in order to start the lamp, and subsequently a low voltage is applied, but with a high electrical power, in order to support the passage of a large current through the lamp during the heating (warming-up) of the lamp and during the subsequent steady operation of the lamp.