Rod-core transformer and a lamp cap having a rod-core transformer

Rod-core transformer for use as a starting transformer in a lamp cap (2) having the following features:

• at least one primary winding (6, 7;
• 6′),
• at least two cores (2, 3) which are in the form of rods, are arranged with their longitudinal axes offset parallel alongside one another, and are composed of an electrically insulating material,
• a first secondary winding (4) whose turns are arranged on the first core (2), with the first secondary winding (4) having a number of parallel-connected layers (4a, 4b, 4c, 4d) of turns, and each layer of turns being arranged without any offset above the next lower layer, so that each turn in any given layer is arranged above the corresponding turn of the layer located immediately underneath it of the first secondary winding (4),
• at least one further secondary winding (5) whose turns are arranged on at least one further core (3) which is in the form of a rod, with the second secondary winding (5) having a number of parallel-connected layers (5a, 5b, 5c, 5d) of turns, and each layer of turns being arranged without any offset above the next lower layer, so that each turn in any given layer is arranged above the corresponding turn of the layer located immediately underneath it of the at least one further secondary winding (5), with
• the secondary windings (4, 5) being electrically conductively connected to one another, and the total resistance of the secondary windings (4, 5) being less than or equal to 2 Ω.