| 摘要 |
PROBLEM TO BE SOLVED: To prevent breakage of elements and reduce losses of elements when FETs are used by reducing reactance of serial connections for bridge connections from element blocks of load driving element blocks to element blocks for flywheel in a load drive circuit such as motor for electric rolling stock, restricting the occurrence of a surge voltage and permitting high-speed switching. SOLUTION: A switching element for drive control and a switching element for circulating current are constituted with element blocks 10, 20 where a plurality of elements are connected in parallel respectively, and both element blocks are bridge connected and a surface current flows through the connections in configuration. A conductive pattern of printed circuit board is used as surface current flowing configuration. By doing this, the reactance is reduced and surge voltage occurrence is restricted, thereby permitting high-speed switching. |
