Techniques are described to adjust the time when a switch is turned on from the time of one voltage valley to the time of another voltage valley for controlling an average load current or average load voltage. In some examples, the adjustment is instantaneous, and in some examples, the adjustment is gradual. Both of these example techniques provide for high switching efficiency of the switch.

A switching converter in which deterioration and breakage can be suppressed is provided. A switching converter whose area can be reduced is provided. The switching converter includes a switch connected to a power supply portion; a transformer connected to the power supply portion; a first rectifying and smoothing circuit and a second rectifying and smoothing circuit each connected to at least the transformer; and a switching control circuit which is connected to the first rectifying and smoothing circuit and the second rectifying and smoothing circuit and which controls operation of the switch. The switching control circuit includes a control circuit controlling on/off of the switch and operation of a starter circuit; and the starter circuit controlling startup of the control circuit. The starter circuit includes a transistor and a resistor each including a wide-gap semiconductor.

The time when a switch is turned on from the time of one voltage valley to the time of another voltage valley may be adjusted for controlling an average load current or average load voltage. In some examples, the adjustment is instantaneous, and in some examples, the adjustment is gradual. Both of these example techniques provide for high switching efficiency of the switch.

The time when a switch is turned on from the time of one voltage valley to the time of another voltage valley may be adjusted for controlling an average load current or average load voltage. In some examples, the adjustment is instantaneous, and in some examples, the adjustment is gradual. Both of these example techniques provide for high switching efficiency of the switch.