Patent ID: 9025975
Filing Date: 2015-05-05
Classification: G03G,H02M,Y02B

Abstract:
1. A switching power source comprising: a transformer; a switching element configured to perform switching a primary side of the transformer; and an output unit configured to output a voltage generated at a secondary side of the transformer, wherein the output unit outputs a first voltage in a first state that the switching element perform switching continuously, and outputs a second voltage that is lower than the first voltage in a second state that the switching element perform switching intermittently, wherein a switching cycle of the switching element is set to be a first switching cycle at the first state, and the switching cycle of the switching element is set to be a second switching cycle that is longer than the first switching cycle at the second state, and a control unit configured to control a timing to turn on the switching element, wherein, at the second state, the control unit turns on the switching element at least three times, wherein, by setting a period for the switching element to be turned on as a first period, the period is lengthened with every time the switching element is turned on, and wherein in a case where the period becomes a predetermined period, the period is set back to the first period.