Patent ID: 7994757

Claim:
A DC-DC converter comprising: a rectifier and a switching device connected in series, a storing device, having a first terminal connected to a connection point of said rectifier and said switching device, and a second terminal connected to a DC power supply, for storing energy during the ON period of said switching device and for discharging the energy via said rectifier during the OFF period of said switching device, a capacitive device, having a first terminal grounded and a second terminal connected to said rectifier, for smoothing the output of said rectifier and for outputting a voltage between the first and second terminals of said capacitive device to a load as an output voltage, a control circuit for generating a drive signal for ON/OFF controlling said switching device by comparing said output voltage with a target voltage, and in a state in which the potential at the connection point of said rectifier and said switching device is detected and said drive signal turns ON said switching device, a protection circuit for turning OFF said switching device at the time when the potential at said connection point is a predetermined potential or more, said predetermined potential being lower than said target voltage.