US Patent 10303232 Computer power supply unit with output mode determining function

A computer power supply unit with output mode determining function includes a voltage difference amplification circuit, a comparison circuit, a linear voltage regulator circuit, a drive circuit and a clamp circuit. A diode is disposed between the first and second input ends of the voltage difference amplification circuit. According to whether the diode generates turn-on bias, the voltage difference amplification circuit outputs a first voltage level. According to the first voltage level and the value of the constant voltage, the comparison circuit outputs a second voltage level. According to the value of the second voltage level, the drive circuit drives or does not drive the clamp circuit so as to judge the output mode of the power supply unit.