| 摘要 |
Bipolar analog input signals are tested for apparent polarity, and depending on the polarity indication, the analog signal is either inverted or not inverted and resulting input signal is combined with a constant reference voltage so that the effective input to the analog-to-digital converter will always be a unipolar voltage having a minimum nominal value greater than the potential error of the polarity decision element. A counter or register type output device, which reflects the digital resultant from the conversion, is corrected by subtracting the digital equivalent of the constant reference voltage, either by presetting the counter to an initial negative value or by subtraction following the conversion. The initial polarity decision further controls the readout, either direct or complemented, to correspond to the apparent polarity of the input signal. |
