To provide a step-up transformer which is miniaturized and remarkably reduces the area for installation on a printed circuit board.
In the step-up transformer for magnetron drive wherein a magnetic circuit composed of inner cores (A1, B1), outer cores (A3, B3) and connecting cores (A2, B2) connecting the inner cores and the outer cores is formed by locating two ferrite cores (18A, 18B) face to face with a void G in between and a primary winding 181 and a secondary winding 182 are provided side by side while surrounding the inner cores (A1, B1), cross-sectional areas of the inner cores (A1, B1) are enlarged, the number of times of winding the primary winding wire 181 and the secondary winding wire 182 in the direction of the diameter is increased, the number of times of winding in the direction of the axis is decreased, the primary winding wire and the secondary winding wire are proximately located, and the ratio of the cross-sectional area of the inner cores (A1, B1) and the cross-sectional areas of the outer cores (A3, B3) is decreased to be ≤ 2:1.
SAKAI SHINICHI
YASUI KENJI
SUENAGA HARUO
Hironori Honda
Toshimitsu Ichikawa
Takeshi Takamatsu
Yuriko Kuriu