Abstract: A power supply device that converts inputted direct-current power to direct-current power with a predetermined voltage to supply the power to the outside includes a voltage conversion circuit that converts the voltage of the inputted direct-current power, a voltage measurement circuit that measures a voltage value indicating a voltage potential difference between a ground voltage potential in the power supply device and a ground point provided outside the power supply device and connected to the ground voltage potential via a ground strap cable, a current measurement circuit that measures a current value of a load current flowing when de direct-current power is supplied from the power supply device, and an arithmetic circuit that calculates a resistance value corresponding ground connection of the power supply device, based on the voltage value measured by the voltage measurement circuit and the current value measured by the current measurement circuit.

Abstract: A power supply device that converts inputted direct-current power to direct-current power with a predetermined voltage to supply the power to the outside includes a voltage conversion circuit that converts the voltage of the inputted direct-current power, a voltage measurement circuit that measures a voltage value indicating a voltage potential difference between a ground voltage potential in the power supply device and a ground point provided outside the power supply device and connected to the ground voltage potential via a ground strap cable, a current measurement circuit that measures a current value of a load current flowing when de direct-current power is supplied from the power supply device, and an arithmetic circuit that calculates a resistance value corresponding ground connection of the power supply device, based on the voltage value measured by the voltage measurement circuit and the current value measured by the current measurement circuit.

Abstract: A mobile terminal device with a camera is provided which can secure emitted light brightness of a camera light unit and save power consumption of the device. During photographing, when the driving power of the camera light unit is increased, driving power for an illumination unit is decreased so that the increase of the total power consumption of the camera light unit and illumination unit can be minimized. In addition, the camera lamp unit and illumination unit are driven by respective driving circuits that share a power supply unit.