Abstract: Loading apparatus for testing a power supply comprises an electronic load circuit, the electronic load circuit comprising an organically and systematically connected mode switching circuit capable switching from and to one another a constant resistance mode, a constant current mode and a slave mode. A load switching circuit is connected to the mode switching circuit and an error amplifier is adapted to input a voltage signal in each of the modes. A field effect transistor circuit is adapted to receive the output of the error amplifier as a gate control signal and has a drain terminal to which is fed the output from a power unit under test and further has a source terminal, the output of which is fed back as a comparison voltage signal to the error amplifier. A current measurement display circuit is branched to the source terminal of the field effect transistor circuit, and an overpower protection warning circuit is also branched to the source terminal.

Abstract: Inrush current measuring apparatus with an instantaneous power interruption device is provided an external power input terminal connected to a commercial power supply and an external power output terminal connected to a power unit under test, which terminals are connected together via a switching circuit section; and is equipped with a power interruption device in which the power supply from the external power input terminal to the external power output terminal is cut off or conducted by opening or closing the switching circuit section.