| 摘要 |
A digital-data to shaft-angle converter that compensates for the non-linear relationship between a 12-bit data word theta 12, representing the desired shaft angle, and its corresponding trigonometric sine and cosine functions as represented by analog voltages. Basically the invention constructs, by empirical means and using linear voltage signals, first and second voltage segments whose amplitudes closely approximate sine and cosine functions, respectively, over the 0 DEG - 45 DEG range. The invention is also capable of constructing by empirical means, third and fourth signals which are mirror images of the first and second signals described above. By proper selection of two of the four possible signals described above and assigning a proper polarity thereto, all in accordance with a truth table, sine and cosine analog voltage signals are generated which can be employed to drive the synchro shaft to any desired angle angular position from 0 DEG to 360 DEG . Both the generation of the 0 - 45 sine and cosine voltage segments (and their mirror images) and the selecting of the proper ones of such generated voltage segments are effected by logic which is directly under the control of the data word theta 12.
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