Circuit for measuring the rate of synchro rotation

Claim 2

A circuit for generating a signal representing the rate of rotation of a synchro comprising: means for generating a cosine signal representing the cosine of the synchro shaft angle; means for generating a sine signal representing the sine of the synchro angle; means responsive to said sine signal and said cosine signal, for generating a tangent signal representing the tangent of the synchro shaft angle; means, responsive to said cosine and said sine signals, for generating a cotangent signal representing the cotangent of the synchro shaft angle; first differentiator means for differentiating said tangent signal into a first rate signal; second differentiator means for differentiating said cotangent signal into a second rate signal; and switch means, responsive to said sine and said cosine signal, for selecting one of said rate signals having substantially linear characteristics.

Claim 3

The circuit of claim 1 wherein said tangent signal generating means additionally includes a first feedback means, responsive to said sine signal, for linearizing said tangent signal.

Claim 4

The circuit of claim 2 wherein said cotangent signal generating means additionally includes feedback means, responsive to said cosine signal, for linearizing said cotangent signal.

Claim 5

The circuit of claim 3 wherein said tangent signal generating means includes: a first integrator means, operatively connected to said cosine signal generating means and a reference voltage, for generating a first integration signal; a first comparator means, operatively connected to said cosine signal generating means and said first integrator means, for comparing said first integration signal to said cosine signal; a first switch means, responsive to said first comparator means, for selectively disconnecting said first cosine signal generating means from said first integrator means; a first filter amplifier means, operatively connected between said sine generator means and said first differentiator means, for filtering and amplifying said sine signal; and a second switch means operatively connected to said first comparator means, for selectively disconnecting said first filter amplifier means from said sine signal generating means.

Claim 6

The circuit of claim 4 wherein said cotangent signal generating means includes: a second integrator means, operatively connected to said sine signal generating means and said reference voltage for generating a second integratIon signal; a second comparator means, operatively connected to said integrator means and said sine signal generating means, for comparing said second integration signal to said sine signal; a third switch means, responsive to said second comparator means, for selectively disconnecting said sine generating means from said second integrator means; a second filter amplifier means, operatively connected between said cosine signal generating means and said second differentiator means, for amplifying and filtering said cosine signal input to said second differentiator means; and a fourth switch means, operatively connected to said second comparator means, for selectively disconnecting said second filter amplifier means from said cosine generating means.

Claim 7

The circuit of claim 5 wherein said first feedback means includes a first function generator operatively connected between said first filter amplifier means and said first integrator means for applying to said first integrator means a signal proportional to the square of said first filter means output.

Claim 8

The circuit of claim 6 wherein said second feedback means includes a second function means, operatively connected between said second filter amplifier means and said second integrator means, for applying to said second integrator means a signal proportional to the square of said second filter means output.

Claim 9

The circuit of claim 7 additionally including means for indicating the validity of said rate signals.

Claim 10

The circuit of claim 8 wherein said validity means includes a logic circuit for measuring the voltage output of said first and said second integrator means and generating a validity signal when at least one of said integrator means is within predefined operating limits.

Claim 11

A circuit for generating a signal representing the rate of rotation of a synchro comprising: a first summing amplifier operatively connected to the three phase output of the synchro and effective to generate a signal representing the cosine of the synchro shaft angle; a second summing amplifier operatively connected to two of the three phase outputs of the synchro and effective to generate a signal representing the sine of the synchro shaft angle; a first integrator circuit including a first summing junction; a first electronic switch operatively connected between said first summing amplifier and said first summing junction; a voltage source operatively connected to said first summing junction; a first comparator circuit, operatively connected and responsive to said first integrator circuit and said first summing amplifier, and effective to control said first electronic switch; a second electronic switch operatively connected to said second summing amplifier and controlled by said first comparator circuit; a first filter amplifier operatively connected to said second electronic switch and effective to generate a signal representative of the tangent of the synchro shaft angle; a first differentiator circuit operatively connected to said first filter amplifier and effective to differentiate said tangent signal into a first rate signal; a second integrator circuit including a second summing junction operatively connected to said voltage source; a third electronic switch operatively connected between said second summing amplifier and said second summing junction; a second comparator circuit operatively connected and responsive to said second integrator circuit and said second summing amplifier and effective to control said third electronic switch; a fourth electronic switch operatively connected to said first summing junction and controlled by said second comparator circuit; a second filter amplifier operatively connected to said fourth electronic switch and effective to generate a signal representative of the cotangent of the synchro shaft angle; a second differentiator circuit operatively connected to said second filter amplifier and effective to differentiate said cotangent signal into a second rate signal; and a third comparator circuit operatively connected to said first and said second summing amplifiers and effective to select one of said rate signals having linear characteristics.

Claim 12

A circuit for generating a signal representing the rate of rotation of a synchro comprising: a first summing amplifier operatively connected to the three phase output of the synchro and effective to generate a signal representing the cosine of the synchro shaft angle; a second summing amplifier operatively connected to two of the three phase outputs of the synchro and effective to generate a signal representing the sine of the synchro shaft angle; a first integrator circuit including a first summing junction; a first electronic switch operatively connected between said first summing amplifier and said first summing junction; a voltage source operatively connected to said first summing junction; a first comparator circuit, operatively connected and responsive to said first integrator circuit and said first summing amplifier, and effective to control said first electronic switch; a second electronic switch operatively connected to said second summing amplifier and controlled by said first comparator circuit; a first filter amplifier operatively connected to said second electronic switch and effective to generate a signal representative of the tangent of the synchro shaft angle; a first differentiator circuit operatively connected to said first filter amplifier and effective to differentiate said tangent signal into a first rate signal; a second integrator circuit including a second summing junction operatively connected to said voltage source; a third electronic switch operatively connected between said second summing amplifier and said second summing junction; a second comparator circuit operatively connected and responsive to said second integrator circuit and said second summing amplifier and effective to control said third electronic switch; a fourth electronic switch operatively connected to said first summing junction and controlled by said second comparator circuit; a second filter amplifier operatively connected to said fourth electronic switch and effective to generate a signal representative of the cotangent of the synchro shaft angle; a second differentiator circuit operatively connected to said second filter amplifier and effective to differentiate said cotangent signal into a second rate signal; and a third comparator circuit operatively connected to said first and said second summing amplifiers and effective to select one of said rate signals having linear characteristics.

Claim 13

The circuit of claim 10 additionally including: a first feedback circuit comprising a function generator circuit, operatively connected between said first filter amplifier and said first summing junction, effective to apply to said first summing junction a signal proportional to the square of the output of said first filter amplifier; and a second feedback circuit comprising a function generator, operatively connected between said second filter amplifier and said second summing junction, effective to apply to said second summing junction a signal proportional to the square of the output of said second filter amplifier.

Claim 14

The circuit of claim 11 additionally including: a first voltage detector operatively connected to said first integrator circuit; a second voltage detector operatively connected to said second integrator circuit; and a logic circuit, operatively connected to said first and said second voltage detectors, effective to generate a validity signal.

Claim 15

An electronic circuit for generating a signal representative of a rate of change in barometric altitude comprising: a synchro where barometric altitude is represented by the angular position of the synchro shaft; means for converting the shaft angle into signals representing the sine and cosine of the shaft angle; means, responsive to said sine and cosine signals, for generating a signal representative to the tangent of the shaft angle; means for differentiating said tangent signal into a first rate signal; means, responsive to said sine and cosine signals, for generating a signal representative of the cotangent of the shaft angle; means for differentiating said cotangent signal into a second rate signal; and means, responsive to said sine and cosine signals for selecting said first or said second rate signal.

Claim 16

An electronic circuit for generating a signal representative of a rate of change in barometric altitude comprising: a synchro where barometric altitude is represented by the angular position of the synchro shaft; means for converting the shaft angle into signals representing the sine and cosine of the shaft angle; means, responsive to said sine and cosine signals, for generating a signal representative to the tangent of the shaft angle; means for differentiating said tangent signal into a first rate signal; means, responsive to said sine and cosine signals, for generating a signal representative of the cotangent of the shaft angle; means for differentiating said cotangent signal into a second rate signal; and means, responsive to said sine and cosine signals for selecting said first or said second rate signal.

Claim 17

The circuit of claim 13 wherein said tangent and said cotangent generating means include feedback means for linearizing said tangent and said cotangent signals.

Claim 18

The circuit of claim 14 additionally including means, responsive to said tangent and cotangent generating means, for generating a signal indicating the validity of said rate signals.