Abstract: A digital to analog converter is provided, for making a digital to analog conversion, and including, an analog to digital converter portion which may be an existing converter, an arithmetic logic unit which is coupled to the analog to digital converter portion, a digital to dc converter portion which is coupled to the arithmetic logic unit, an ac multiplex circuit for an ac operation which is adapted to be coupled to the digital to dc converter portion, a dc multiplex circuit for a dc operation which is adapted to be coupled to the digital to dc converter portion, a switch which couples either the ac multiplex circuit or the dc multiplex circuit to the digital to dc converter portion and which is coupled to and operated by the arithmetic logic unit, and a multiplex control which is actuated by the analog to digital converter portion and which is coupled to the ac multiplex circuit and to the dc multiplex circuit for controlling the output signals from the ac circuit and dc circuit to the analog to digital con