| 摘要 |
A flyback converter has a primary side including a main switch and a control device and a delay circuit. The converter has a secondary side including a drive circuit controlling a rectifying switch. The drive circuit has a first part including a first transistor, a first discharge diode and an on-node and a second part including a second transistor, a second discharge diode and an off-node. The control device is connected to the drive circuit via at least one drive capacitor to the on- and off-nodes. The control device issues drive pulses to the main switch through the delay circuit and to the drive circuit. The drive circuit has a first mode of operation in a flyback phase, which is triggered when the main switch is turned off and the rectifying switch is rendered conducting. A second mode of operation is a forward phase, which is triggered when the main switch is turned on and the rectifying switch is rendered non-conducting. The flyback converter includes few components and the main switch is efficiently prevented from conducting simultaneously with the rectifying switch. |
