A new switching power supply with super wide voltage input range based on boost and flyback circuit was presented in this paper. The boost circuit was controlled by L6561 and flyback circuit was controlled by TOPSwitch. When input voltage was low, this voltage was stepped up by boost circuit and then converted by flyback circuit. ff input voltage was high, this voltage was connected to flyback circuit directly. These two modes were controlled by a hysteresis comparator. The experimental results show that when input AC voltage changes from 25 to 265 V, the output voltage is very stable.%介绍了一种基于升压电路和反激电路的超宽输入范围的开关电源电路.其中升压电路采用PFC控制芯片实现,反激电路采用TOPSwitch控制.在输入电压较低的情况下,采用先升压再DC/DC变换的工作模式;在输入电压较高的情况下,直接采用DC/DC变换的模式.两种模式的切换采用迟滞比较器进行控制.实验结果表明,当输入范围达到交流约25 V~265 V的超宽范围时,该电路仍然能够保持良好的性能.
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