needs to be applied to the noninverting input terminal of the comparator 104 that is when the output voltage vout is low causing a more current to flow through the switch 107 inverts the output signal from the comparator 104 an output signal from the comparator 104 is inputted to a reset terminal r of an sr latch 106 through an or circuit 115 similarly to the case of the comparator 104 the signal which is obtained by converting the current caused to flow through the switch 107 into the voltage is inputted to a noninverting input terminal of an over current detecting comparator 114 as described above normally the current is detected using the sense resistor connected in series with the switch 107 the signal having the value proportional to the current caused to flow through the switch 107 is also inputted as the voltage information to the noninverting input terminal of the over current detecting comparator 114 in addition a reference voltage source 113 is connected to an inverting terminal of the over current detecting comparator 114 an output terminal of the over current detecting comparator 114 is connected to one input terminal of the or circuit 115 moreover an output signal from the over current detecting comparator 114 is inputted to a pulse adjusting circuit.