Patent attributes
A switching power supply device includes a power factor improvement circuit, a phase-shifted full bridge type DC/DC converter that is arranged in a rear stage of the power factor improvement circuit and has a full-bridge type switching circuit, an output current detecting circuit for detecting an output current to be supplied to a load, an output voltage detecting circuit for detecting an output voltage to be supplied to the load, and a power factor improvement circuit output voltage detecting circuit for detecting a power factor improvement circuit output voltage, which is input from the power factor improvement circuit to the DC/DC converter. The switching power supply device further includes a control unit for dynamically changing dead times of the full-bridge type switching circuit based on the power factor improvement circuit output voltage, and the output current and the output voltage to be supplied to the load, and the control unit applies the dead times that have been changed to control switching of the full-bridge type switching circuit.
