| 摘要 |
PURPOSE:To further stabilize an output power supply by reducing fluctuation in drive conditions for a switching element caused by the fluctuation in an input power supply in a switching power supply circuit. CONSTITUTION:An input power supply is switched by using a switching element Tr1 and switched power supply signals are smoothened by a smoothening circuit portion L1 and C3 and a power supply of a constant voltage is output from output terminals in a switching power supply apparatus 1, detection circuits L1 and L2 outputting signals corresponding to the fluctuation in the input power supply are provided in the smoothening circuit portion L1 and C3 and a drive current of a switching element is controlled on the basis of signals detected in the detection circuit. |
