| 摘要 |
The present invention concerns an universal input switching power supply unit of a ringing choke converter (RCC) system in which by reducing the number of components, cost saving and mounting space reduction can be achieved. For high input voltages (Vin) and light loads, the inductance of a primary winding (N1) of a main transformer (T) is set high, preventing however that the switching voltage exceeds a rated value of the switching element (Q1). For low input voltages (Vin) and heavy loads, the inductance of the primary winding (N1) is set low along with a control resistance (R2) and a control capacitance (C1), preventing anyhow the deterioration of the switching characteristics. <IMAGE> |
