Patent ID: 8004380

Claim:
A transformer including an integral output coil, the transformer comprising: a pair of bottom plates arranged substantially parallel to each other; a first magnetic lead and a second magnetic lead arranged at a center part of the bottom plates with a predetermined space therebetween; a third magnetic lead provided outside the first magnetic lead; a first core formed by the first magnetic lead through the third magnetic lead; a fourth magnetic lead provided outside the second magnetic lead; a second core formed by the second magnetic lead and the fourth magnetic lead; a first winding wound around the first magnetic lead but not the second magnetic lead; a second winding passing through between the first magnetic lead and the second magnetic lead and forming a first transformer together with the first winding; a third winding passing through between the first magnetic lead and the third magnetic lead and forming a second transformer together with the first winding; and a fourth winding having one end thereof connected to one end of the second winding and one end of the third winding, the fourth winding passing through between the second magnetic lead and the fourth magnetic lead, wherein the first core with the first winding through the third winding serves as the transformer, and the second core with the fourth winding serves as the integral output coil, and wherein in the first core, magnetic flux generated by the first winding flows through two paths, one of which is a path through the first magnetic lead and the second magnetic lead and the other of which is a path through the first magnetic lead and the third magnetic lead.