Apparatus for signalling an angular displacement of a body about an axis

Claim 5

Apparatus for signalling the angular displacement of the rotor of a synchro transmitter or resolver about an axis, comprising: means for deriving from the synchro transmitter or resolver two cyclic signals varying with (sin phi sin omega t) and (cos phi sin omega t), respectively, where phi is the rotor shaft angle and omega the angular frequency of the supply voltage; first signal-processing means for deriving from the first cyclic signal a first series of pulses which have a given frequency and an amplitude equal to the peak value of the first cyclic signal; second signal-processing means for deriving from the second cyclic signal a second series of pulses which have the said given frequency and an amplitude equal to the peak value of the second cyclic signal, the second series of pulses being in phase quadrature with the first serieS of pulses; third signal-processing means for combining the first and second series of pulses and deriving from the combination a signal which is a function of ( omega nt + phi ), where n is the said pulse frequency, and means for comparing the signal which is a function of ( omega nt+ phi ) with a reference phase signal at the frequency n to obtain an indication of the rotor shaft angle phi .

Claim 6

Apparatus for signalling the angular displacement of the rotor of a synchro transmitter or resolver about an axis, comprising: means for deriving from the synchro transmitter or resolver two cyclic signals varying with (sin phi sin omega t) and (cos phi sin omega t), respectively, where phi is the rotor shaft angle and omega the angular frequency of the supply voltage; first signal-processing means for deriving from the first cyclic signal a first series of pulses which have a given frequency and an amplitude equal to the peak value of the first cyclic signal; second signal-processing means for deriving from the second cyclic signal a second series of pulses which have the said given frequency and an amplitude equal to the peak value of the second cyclic signal, the second series of pulses being in phase quadrature with the first serieS of pulses; third signal-processing means for combining the first and second series of pulses and deriving from the combination a signal which is a function of ( omega nt + phi ), where n is the said pulse frequency, and means for comparing the signal which is a function of ( omega nt+ phi ) with a reference phase signal at the frequency n to obtain an indication of the rotor shaft angle phi .

Claim 7

Apparatus for signalling the angular displacement of the rotor of a synchro transmitter or resolver about an axis, comprising: means for deriving from the synchro transmitter or resolver two cyclic signals varying with (sin phi sin omega t) and (cos phi sin omega t) respectively, where phi is the rotor shaft angle and omega the angular frequency of the supply voltage; sample-and-hold circuits for periodically sampling each of these signals at corresponding points in different cycles of the signal and holding the sampled signal levels; means for deriving two periodic signals at equal frequency in quadrature phase relationship; chopping means for chopping the two samples signals respectively with the said two quadrature-phase signals; signal-processing means for combining the chopped signals and deriving therefrom a signal which is a function of ( omega nt + phi ), where nis the frequency of the chopping signals, a comparator connected to receive and compare the signal which is a function of ( omega nt+ phi ) with a reference phase signal at the chopping frequency; and means responsive to the result of the comparison to provide a digital representation of the rotor shaft angle.

Claim 8

Apparatus for signalling the angular displacement of the rotor of a synchro transmitter or resolver about an axis, comprising: means for deriving from the synchro transmitter or resolver two cyclic signals varying with (sin phi sin omega t) and (cos phi sin omega t) respectively, where phi is the rotor shaft angle and omega the angular frequency of the supply voltage; sample-and-hold circuits for periodically sampling each of these signals at corresponding points in different cycles of the signal and holding the sampled signal levels; means for deriving two periodic signals at equal frequency in quadrature phase relationship; chopping means for chopping the two samples signals respectively with the said two quadrature-phase signals; signal-processing means for combining the chopped signals and deriving therefrom a signal which is a function of ( omega nt + phi ), where nis the frequency of the chopping signals, a comparator connected to receive and compare the signal which is a function of ( omega nt+ phi ) with a reference phase signal at the chopping frequency; and means responsive to the result of the comparison to provide a digital representation of the rotor shaft angle.

Claim 9

Apparatus in accordance with claim 4, in which the means for deriving two periodic signals at equal frequency in quadrature-phase relationship includes a high-frequency pulse generator and frequency dividing means.

Claim 10

Apparatus in accordance with claim 5, in which the means for providing a digital representation of the rotor shaft angle includes the said high-frequency pulse generator, a counter and a gate responsive to the result of the comparison to control the interval for which pulses from the generator are applied to the counter.

Claim 11

Apparatus in accordance with claim 3, in which the means for deriving the two cyclic signals includes a Scott transformer.

Claim 12

Data indicating or recording equipment including apparatus in accordance with claim 3 together with multiplexing means for successively connecting different synchro transmitters or resolvers to the said apparatus.