Course/fine synchro altimeter converter

Claim 2

A coarse/fine synchro altimeter converter comprising: means responsive to separate signals respectively representing coarse altitude and fine altitude to develop a coarse voltage staircase as a function of altitude, the increments in said staircase being equivalent to the maximum altitude range represented by said fine altitude signal; means responsive to said coarse voltage staircase for generating a precision voltage staircase of substantially the same magnitude as said coarse voltage staircase for any give altitude represented by said coarse and fine altitude signals; and means for summing said precision voltage staircase with said fine altimeter signal to provide a single signal indicative of altitude to substantially the same degree of precision as said fine altimeter signal.

Claim 3

An altimeter converter according to claim 1 wherein said precision staircase generating means includes a precision D/A converter.

Claim 4

An altimeter converter according to claim 2 wherein said precision staircase generating means comprises means for comparing said coarse staircase voltage with said precision staircase voltage; an up/down counter, the output of which is connected to the input of said precision D/A converter; and means responsive to the output of said staircase comparing means to increase the count in said counter when said coarse staircase exceeds, by substantially one increment, said precise staircase and for causing said up/down counter to count down one count when said precision staircase exceeds, by more than one increment, said coarse staircase voltage.

Claim 5

An altimeter converter according to claim 2 wherein said precision staircase generating means additionally comprises a plurality of comparators, each for sensing a distinct increment step in said staircase voltage, the output of said plurality of comparators being utilized to provide corresponding inputs to said precision D/A converter.

Claim 6

An altimeter converter according to claim 1 wherein said precision staircase generating means comprises: means for sensing the voltage level of said voltage staircase; and means responsive to said sensing means for generating a corresponding, precise voltage level.

Claim 7

An altimeter converter according to claim 1 wherein said precise staircase generating means comprises: an up/down counter; means responsive to the output of said up/down counter to generate a precise voltage corresponding to the count therein; and means comparing said precise voltage with said coarse voltage staircase and for incrementing said counter when said precise voltage is less by one increment than said coarse voltage and for decrementing said up/down counter when said precise voltAge is greater by one increment than said coarse voltage.

Claim 8

A shaft angle encoder comprising: means providing differential signals together indicative of mechanical shaft angles; means responsive to said differential signals to provide an indication of whether the shaft angle is in a first range of shaft angles which fall between a first angle through to a second angle, or in a second range of shaft angles which fall between said second angle through to said first angle, alternatively; means responsive to said angle range indication means for reversing the phase of said differential signals in one range of angles and not in the other range of angles, and for providing +180* bias in one said range of angles and not in the other of said range of angles; means providing a negative bias proportional in magnitude to the upper angle of the range of said angles in which said +180* of bias is provided; an RC/CR bridge means responsive to the outputs of said phase reversing means for providing output signals, the electrical phase of which is related to shaft angle; means responsive to said bridge output signals for providing an output manifestation representing outputs of said bridge corresponding to shaft angles between 180* and said second angle and providing a basic angle signal representing the output of said bridge and corresponding to the shaft angle; means responsive to said manifestation for providing a bias signal representing a 180* shaft angle; and means providing a signal proportional to the time average of the sum of said basic angle signal and said bias signals.

Claim 9

A shaft angle encoder comprising: means providing differential signals together indicative of mechanical shaft angles; means responsive to said differential signals to provide an indication of whether the shaft angle is in a first range of shaft angles which fall between a first angle through to a second angle, or in a second range of shaft angles which fall between said second angle through to said first angle, alternatively; means responsive to said angle range indication means for reversing the phase of said differential signals in one range of angles and not in the other range of angles, and for providing +180* bias in one said range of angles and not in the other of said range of angles; means providing a negative bias proportional in magnitude to the upper angle of the range of said angles in which said +180* of bias is provided; an RC/CR bridge means responsive to the outputs of said phase reversing means for providing output signals, the electrical phase of which is related to shaft angle; means responsive to said bridge output signals for providing an output manifestation representing outputs of said bridge corresponding to shaft angles between 180* and said second angle and providing a basic angle signal representing the output of said bridge and corresponding to the shaft angle; means responsive to said manifestation for providing a bias signal representing a 180* shaft angle; and means providing a signal proportional to the time average of the sum of said basic angle signal and said bias signals.

Claim 10

A shaft angle encoder according to claim 7 and further comprising: means providing a bias equal to a few degrees of shaft angle and applying said bias to said phase reversing and bias signal providing means, thereby providing for a delay in transition of the operation thereof as said shaft angle decreases from an angle within said range of angles to an angle outside of said range of angles, whereby, within said few degrees below said first angle said means will not alter its phase reversal of said differential signals and will not alter said +180* bias.