| 摘要 |
PROBLEM TO BE SOLVED: To reduce power loss, even for a snubber circuit of a power device which performs high-speed switching operation, by causing it to have a series circuit composed of a capacitor and a diode, and moreover providing a capacitor connected in parallel to the diode. SOLUTION: A snubber circuit of a power device 11 comprises a diode 12, connected in opposite parallel to the power device 11, a series circuit composed of a capacitor 13 and a diode 14, a resistor 16, and a capacitor 17 connected in parallel with the diode 14. This snubber circuit suppresses a voltage increase rate (dV/dt) from a time t1 to a time t2, when the power device 11 is under turn-off operation. The rate dV/dt can be made smaller after the time t2, if the capacity of the capacitor 13 is made larger than that of the capacitor 17. The greater part of the energy stored in the snubber circuit, when the power device 11 is turned off, is regenerated via the resistor 16, and increase of the operation efficiency becomes feasible. |
