Read-out circuits for electrical position-encoders

Claim 1

An electrical position encoder comprising: a. a movable member; b. means for deriving from said member a plurality of positionresponsive signals having values which fluctuate alternately positively and negatively with respect to respective intermediate values as functions of position of the movable member, i. the positional extents of the positive and negative fluctuations of said signals being in respective predetermined ratios, ii. the combination of polarities of said position-responsive signals with respect to their respective said intermediate values at any given time being characteristic, according to a first binary position code, of the particular one of a plurality of adjacent ranges of position occupied by said movable member at that time; c. a plurality of signal paths to which said position responsive signals are respectively applied; and d. a plurality of decision circuits each connected to a respective one of said signal paths to produce a binary output signal comprising a mark or a space according to the instantaneous value of the position-responsive signal applied to the corresponding said path, relative to a decision level; e. the positional extents of the marks and spaces of at least one of said binary output signals being in a mark/space ratio which differs from said predetermined ratio of the positive and negative fluctuations of the corresponding positionresponsive signal, f. whereby the combination of the values of said binary output signals, at any given time is characteristic, according to a second binary position code, of the particular one of a different plurality of adjacent ranges of position that is occupied by said member at that time.