Patent ID: 9300216
Filing Date: 2016-03-29
CPC Classification: G03G,H02M,Y02B

Claim Text:
1. A power supply device including a transformer having a primary winding and a secondary winding, and a switching element connected to the primary winding configured to drive the transformer to output voltage from the secondary winding, the power supply device comprising: a control unit configured to drive the switching element such that the switching element is turned on and, when first signal value of a signal according to current flowing to the primary winding reaches second signal value of a signal according to voltage output from the secondary winding, the switching element is turned off, wherein, in a case where the control unit performs an intermittent drive operation which repeats a period for which the switching element is driven and a period for which the drive of the switching element is stopped, when the second signal value of a signal according to the voltage output from the secondary winding is between a first reference value and a second reference value greater than the first reference value the control unit drives the switching element such that the switching element is turned off before first signal value of a signal according to the current flowing to the primary winding reaches second signal value of a signal according to the voltage output from the secondary winding in the period for which the switching element is driven.