DC/DC单片开关电源故障分析与诊断

Failure diagnosis and analysis of DC/DC switching power supply single-chip

运用开关频率这一重要理论,针对单片开关电源的检修研究探讨了一种新的故障排除法,即输入电流和输出电压数据测试对比法。此方法是以开关管与线性光耦之间的非正常联系作为故障基本特征,快速锁定故障点。然后,根据故障点查看取样电阻与线性光耦构成的反馈电路状态正确与否,采用脉冲宽度调制方式,在开关频率一定时,调节脉冲宽度来改变占空比,确保开关电源有稳定的电压输出。此方法直观、快捷、诊断时间短,电路易恢复。并且适合用于其他种类的开关电源的维修与维护。

An obstacle removing method for checking single chip power supply via data test and comparison of input currency and output voltage is proposed based on the theory of switching frequency. The failure points can be found rapidly according to the characteristic of the abnormal relationship between line and optocoupler, view point of failure with the sampling resistor consisting of linear optocoupler feedback circuit in the right state or not, using pulse width modulation, in a certain switching frequency, pulse width adjustment to change the duty cycle, switching power supply to ensure a stable voltage output. This method is visual, fast, short-time diagnosis,electricity louis restores. And suitable for other types of switching power supply repair and maintenance.