Abstract: Noise induced hunting is eliminated in successive ranged digital/analog converter bias correction circuits by means of a digital hysteresis circuit. The digital hysteresis circuit comprehends a first up/down counter that counts to its extremums from a pre-set intermediate state in response to enable and up/down input signals. For each extremum count an enable output pulse and a reset pulse is generated at the counter output. The enable output pulses are counted by a second up/down counter the output of which drives a digital/analog converter. Each reset pulse resets the first up/down counter to its pre-set state.

Abstract: An automatic bias adjustment circuit for a successive ranged analog/digital converter (SRADC) that eliminates the need for manual bias adjustments and calibration inputs. The bias correction circuit comprehends dual flip flops that are triggered by selected comparators of the SRADC n bit parallel analog/digital converter. The flip flop output signals control up/down counters whose output bits drive digital/analog converter. The digital/analog converted signals are introduced back into the SRADC analog chain to zero bias errors in a particular sub-range. A disabling circuit prevents operation of the bias adjustment circuits for the first sub-range.

Abstract: A harmonic oscillator coordinate converter in combination with analog and digital circuits is described which may accept signals indicative of a measured angle and of a misalignment angle to provide coordinate conversions of a vector through the measured angle and the misalignment angle during a single angle transformation.

Abstract: An electronically controlled coordinate converter for transforming vectors from a first coordinate system to a second coordinate system through an input angle is provided using a harmonic oscillator which is responsive to an oscillation angle control signal having a discontinuity or transition point wherein an incremental change in the input angle at a predetermined value causes a step function in the duration of said oscillation angle control signal. The discontinuity in the oscillation angle control signal is eliminated by control circuits within a selected range of input angles where the error effects due to transformations on either side of the discontinuity are avoided.