DC POWER SOURCE DEVICE, ELECTRIC MOTOR DRIVE DEVICE, AIR CONDITIONER, AND REFRIGERATOR

摘要

This DC power source device is provided with: a switch (7) configured from a first switching element (4a) and a second switching element (4b); and a control unit (8) that controls the operation of the first switching element (4a) and the second switching element (4b). The switch (7) has a first mode, in which the on duty ratio is a first value, and a second mode, in which the on duty ratio is a second value greater than the first value. When transitioning the switch (7) from the first mode to the second mode, the control unit (8) controls the switch (7) in a manner so that the time until the on duty ratio reaches the second value is at least a certain time, and after the on duty ratio has reached the second value, controls in a manner so that the operation cycle of the switch (7) is elongates.