A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.