Method for starting boost DC/DC circuits with isolating transformers and apparatus thereof

摘要

A method for starting a boost DC/DC circuit with isolating transformer is provided. A charging operation on an output side capacitor is achieved through controlling the turn-on and 5 turn-off of four power transistors at an input side, and the starting process is accomplished when the voltage across the output side capacitor reaches the voltage threshold. The starting method may be realized based on a conventional circuit without modifying the circuit structure, and no power- consumption component such as resistor is added to the circuit, thus no extra loss is produced in the starting process. An apparatus for starting the boost DC/DC 0 circuit with isolating transformer is further provided. Figure 2 Turning on a first power transistor pair to charge the output side capacitor Turning off the first power transistor pair when the turn-on time of the first power transistor pair reaches a first duration Turning on the clamp power transistor to reset / the input inductor Turning off the clamp power transistor when the turn-on time of the clamp power transistor reaches a second duration Turning on the second power transistor pair to / charge the output side capacitor Turning off the second power transistor pair when the turn-on time of the second power transistor pair reaches the first duration Turning on the clamp power transistor to reset the input inductor Turning off the clamp power transistor when the turn-on time of the clamp power transistor reaches the second duration Figure 2