| 摘要 |
A switched mode power supply apparatus is equipped with a start-up device supplying electrical energy to a controller which controls the switching of a switching transistor. The start-up device is bypassed by a bypass-device. During start-up of the power supply, the bypass-device is open. After a successful start-up, the bypass-device will be closed, eliminating further dissipation in the start-up device, and therefore increasing the overall energy efficiency of the power supply. By connecting the start-up device to a stand-by power supply or to a primary voltage, use of an additional winding on the transformer to supply the controller is obviated. The power supply has an electronic overload protection, and will stop and periodically attempt a restart when an overload condition occurs. |
