Power supply apparatus

A power supply apparatus comprising:

• a plurality of power supply terminals to which one of a plurality of different voltages is adapted to be applied;
• a rectifying circuit for rectifying a voltage coupled thereto from said power supply terminals to develop, between two output terminals thereof, a rectified voltage in accordance with the coupled voltage;
• a plurality of inverters;
• a connecting circuit for connecting said plurality of inverters into one of a plurality of inverter connections in response to an inverter connection indicative signal applied thereto, said inverter connections corresponding to respective ones of said plurality of different voltages and being arranged such that a predetermined voltage can be applied to each of said inverters whichever one of said plurality of different voltages is applied to said power supply terminals;
• an inverter connection indicative signal generating circuit manually operated to generate said inverter connection indicative signal corresponding to one of said plurality of inverter connections;
• a normally open switch disposed in a path extending between said two output terminals of said rectifying circuit and said plurality of inverters, said normally open switch being closed in response to a CLOSE signal applied thereto;
• a voltage detecting circuit for generating said inverter connection indicative signal corresponding to one of said plurality of voltages as applied to said power supply terminals;
• a judging circuit for judging, when one of said plurality of voltages is applied to said power supply terminals, whether said inverter connection indicative signal generated by said voltage detecting circuit matches said inverter connection indicative signal generated by said inverter connection indicative signal generating circuit;
• a normally-open-switch driving circuit for supplying said normally open switch with said CLOSE signal when said judging circuit judges that said inverter connection indicative signals from said voltage detecting circuit and said inverter connection indicative signal generating circuit match;
• and
• an alarm circuit activated to provide an alarm when said judging circuit judges that said inverter connection indicative signal from said voltage detecting circuit does not match said inverter connection indicative signal generated by said inverter connection indicative signal generating circuit.