| 摘要 |
PROBLEM TO BE SOLVED: To provide a step-down DC-DC converter in which reduction of radiation electromagnetic wave noise is realized. SOLUTION: A single phase DC voltage (secondary voltage) outputted from the secondary coil of a transformer 6 is rectified through a diode module 80. A bus bar 19 for grounding the joint (i.e. neutral) of both secondary coils of the transformer 6 is located between a circuit board 30 and the diode module 80 and extended substantially in parallel with the circuit board 30 while covering a bus bar 18 and the diode module 80. According to the arrangement, a large electromagnetic wave noise on the bus bar 18 connecting the transformer 6 and the diode module 80 and on the diode module 80 can be prevented from entering into circuit elements 32, 33 on the circuit board 30. |
