A power conversion device comprising: an inverter circuit which converts DC power into AC power and which includes a plurality of switching devices (130 and 150) constituting an upper arm and a lower arm; a control circuit which outputs a PWM gate signal to control the plurality of switching devices (130 and 150); a drive circuit which drives the plurality of switching devices (130 and 150) based on the gate signal from the control circuit; and a power supply circuit which supplies power to the drive circuit; wherein: the control circuit controls a power supply voltage to be output from the power supply circuit to the drive circuit; the drive circuit drives the plurality of switching devices (130 and 150) based on the gate signal from the control circuit and the power supply voltage; the power supply circuit includes a transformer (103 or 803), a power supply control IC, and a feedback output circuit (107, 807, 1003 or 1203), wherein the transformer (103 or 803) includes a primary coil to which a voltage is supplied from a battery via a switch element, and a plurality of secondary coils (220 or 804 and 221) to which voltages are supplied through the primary coil respectively; the power supply control IC controls a current flowing in the primary coil, and the feedback output circuit (107, 807, 1003, or 1203) outputs a voltage signal to the power supply control IC, the voltage signal corresponding to the output voltage of the power supply circuit output to the drive circuit; among the secondary coils (220 or 804 and 221), a plurality of first secondary coils outputs a voltage to the drive circuit; among the secondary coils (220 or 804 and 221), a second secondary coil (220 or 804) outputs a voltage to the feedback output circuit (107, 807, 1003 or 1203); and the feedback output circuit (107, 807, 1003 or 1203) includes a dummy load circuit (201, 801, 1001 or 1201) configured to change the voltage signal output to the power supply control IC based on a change of the frequency of the gate signal. an inverter circuit which converts DC power into AC power and which includes a plurality of switching devices (130 and 150) constituting an upper arm and a lower arm; a control circuit which outputs a PWM gate signal to control the plurality of switching devices (130 and 150); a drive circuit which drives the plurality of switching devices (130 and 150) based on the gate signal from the control circuit; and a power supply circuit which supplies power to the drive circuit; the control circuit controls a power supply voltage to be output from the power supply circuit to the drive circuit; the drive circuit drives the plurality of switching devices (130 and 150) based on the gate signal from the control circuit and the power supply voltage; the power supply circuit includes a transformer (103 or 803), a power supply control IC, and a feedback output circuit (107, 807, 1003 or 1203), wherein the transformer (103 or 803) includes a primary coil to which a voltage is supplied from a battery via a switch element, and a plurality of secondary coils (220 or 804 and 221) to which voltages are supplied through the primary coil respectively; the power supply control IC controls a current flowing in the primary coil, and the feedback output circuit (107, 807, 1003, or 1203) outputs a voltage signal to the power supply control IC, the voltage signal corresponding to the output voltage of the power supply circuit output to the drive circuit; among the secondary coils (220 or 804 and 221), a plurality of first secondary coils outputs a voltage to the drive circuit; among the secondary coils (220 or 804 and 221), a second secondary coil (220 or 804) outputs a voltage to the feedback output circuit (107, 807, 1003 or 1203); and the feedback output circuit (107, 807, 1003 or 1203) includes a dummy load circuit (201, 801, 1001 or 1201) configured to change the voltage signal output to the power supply control IC based on a change of the frequency of the gate signal.