To obtain a compound winding transformer with easy circuit design and a lamp lighting device with a small variation in luminance by avoiding a heat concentration on a plurality of the winding transformers and specific transformers and facilitating the matching of characteristics caused by a magnetic flux distribution.

There is provided a compound winding transformer 7 characterized by being provided with a plurality of winding transformers 7a and 7b and a covering member 13 integrating the plurality of winding transformers 7a and 7b, which have cores 8, primary windings 9 and secondary windings 10 formed in the cores 8, and terminal electrodes 11 electrically connected with the primary windings 9 and the secondary windings 10. There is also provided a lamp lighting device mounted with the same.

COPYRIGHT: (C)2007,JPO&INPIT