Switching power supply, starting resistor is very hot, no output. What is the reason.
You ask the question is the common problem of switching power supply, you have to study the power schematic diagram! Practice basic skills.
If it is the circuit, to check the chip's operating point has not met the requirements, but also to check the over-sampling voltage is not high, Vref voltage is wrong, RtCt circuit is no problem.
That is, switching power supply can not afford to vibrate, if it is self-oscillation to check the rectifier components are not short-circuit, positive feedback circuit is not normal.
