| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that power loss increases when a power switching element Sw is switched on when a current is flowing to a free wheel diode FD. <P>SOLUTION: The cathode potential of the free wheel diode FD is raised by a specified voltage Vp by a power source 74, and it is applied to the anode of a diode 70 for detection. The cathode side of the diode 70 for detection is connected to the cathode side of the free wheel diode FD. A shunt resistor 72 is connected to the anode of the diode 70 for detection, and when determined that a current is flowing to the free wheel diode FD, based on the voltage drop of the shunt resistor 72, it compulsively switches off the power switching element Sw. <P>COPYRIGHT: (C)2010,JPO&INPIT |
