Patent ID: 8203381

Claim:
A voltage output device comprising: an operational amplifier having an inverting input terminal and a non-inverting input terminal; connection switching means for switching between connection and disconnection of the inverting input terminal to or from the non-inverting input terminal; load resistance changing means for changing either one or both of resistance values of a load resistor on the inverting input side and a load resistor on the non-inverting input side of the operational amplifier with the inverting input terminal and the non-inverting input terminal being mutually connected; and load resistance setting means for allowing resistance values of the load resistor on the inverting input side and the load resistor on the non-inverting input side to be maintained, with the resistance values being obtained when an output voltage of the operational amplifier has changed while with the inverting input terminal and the non-inverting input terminal mutually connected, either one or both of the resistance values of the load resistor on the inverting input side and the load resistor on the non-inverting input side are sequentially varied, wherein the voltage output device is configured to output the output voltage of the operational amplifier when the inverting input terminal and the non-inverting input terminal are not mutually connected.