Servoed meter apparatus

Claim 2

An electromagnetic transducer comprising: a D''Arsonval-type meter structure having a magNetic core means arranged to define a unidirectional magnetic flux field, means coupled with said core means for producing an alternating magnetic flux field substantially coextensive with said unidirectional flux field, an armature winding mounted for movement relative to said core means and having convolutions thereof adapted to be displaced through said flux fields, and means coupled with said winding for displacing the same whereby there is induced in said winding an alternating current signal component having a phase and amplitude proportional to the direction and magnitude of said displacement through interaction with said alternating magnitude flux and a direct current signal component of polarity and amplitude proportional to the direction and magnitude of the rate of change of said displacement through interaction with said unidirectional magnetic flux.

Claim 3

The transducer as set forth in claim 1 wherein said winding displacing means comprises a further armature winding mounted integrally and substantially coextensive with said first mentioned armature winding and means for supplying a direct current displacement control signal to said further winding whereby both said armature windings are displaced through interaction with said unidirectional field in accordance with the polarity and amplitude of said control signal.

Claim 4

Apparatus for positioning an indicator pointer in closed-loop servo fashion in accordance with the control signal comprising: meter movement means of the D''Arsonval-type having a magnetic core means for producing a unidirectional magnetic flux field, means coupled with said core means for producing an alternating magnetic flux field substantially coextensive with said unidirectional magnetic flux field, and a pivotally mounted armature means including a pair of coils having convolutions thereof adapted to move in both of said flux fields, means supplying a reversible polarity, variable magnitude DC control signal to one of said coils for displacing said armature through the reaction of said unidirectional magnetic field in accordance with the sense and magnitude of said control signal and thereby displacing said other coil with respect to said alternating magnetic field whereby there is induced therein an alternating current having a phase and amplitude proportional to the direction and magnitude of said displacement through reaction with said alternating magnetic field, and means coupled with said other coil for supplying a servoloop feedback signal proportional to said armature displacement.

Claim 5

Apparatus for positioning an indicator pointer in closed-loop servo fashion in accordance with the control signal comprising: meter movement means of the D''Arsonval-type having a magnetic core means for producing a unidirectional magnetic flux field, means coupled with said core means for producing an alternating magnetic flux field substantially coextensive with said unidirectional magnetic flux field, and a pivotally mounted armature means including a pair of coils having convolutions thereof adapted to move in both of said flux fields, means supplying a reversible polarity, variable magnitude DC control signal to one of said coils for displacing said armature through the reaction of said unidirectional magnetic field in accordance with the sense and magnitude of said control signal and thereby displacing said other coil with respect to said alternating magnetic field whereby there is induced therein an alternating current having a phase and amplitude proportional to the direction and magnitude of said displacement through reaction with said alternating magnetic field, and means coupled with said other coil for supplying a servoloop feedback signal proportional to said armature displacement.

Claim 6

The apparatus as set forth in claim 3 wherein a DC signal is produced in said other coil proportional to the rate of change of said displacement through reaction with said unidirectional field and further including means responsive to said DC component for supplying a further servoloop feedback signal proportional to the rate of movement of said armature.

Claim 7

Apparatus for positioning an indicator comprising: meter movement means of the D''Arsonval-type including magnetic core means for producing a unidirectional magnetic field, means coupled with said core means for producing an alternating magnetic field substantially collinear with said unidirectional magnetic field, and pivotally mounted armature means having first and second coils so arranged and constructed that convolutions of each are adapted to move across both of said magnetic fields, driver means having input terminals for receiving a reversible polarity, variable magnitude DC command signal and an output terminal connected to the first coil to provide a control signal thereto for displacing the armature through reaction with the unidirectional magnetic field in accordance with the magnitude and sense of the control signal whereby the second coil is displaced with respect to the alternating magnetic field so that there is induced therein through reaction with the alternating magnetic field an AC feedback signal having a frequency correspondinG to that of the alternating magnetic field and an amplitude and phase proportional to the magnitude and direction of said displacement and through reaction with said unidirectional magnetic field a DC feedback signal having an amplitude and polarity proportional to the rate of change and direction of said displacement, and feedback means coupling the second coil to the first coil such that the AC and DC feedback signals are degeneratively combined with the command signal.

Claim 8

Apparatus for positioning an indicator comprising: meter movement means of the D''Arsonval-type including magnetic core means for producing a unidirectional magnetic field, means coupled with said core means for producing an alternating magnetic field substantially collinear with said unidirectional magnetic field, and pivotally mounted armature means having first and second coils so arranged and constructed that convolutions of each are adapted to move across both of said magnetic fields, driver means having input terminals for receiving a reversible polarity, variable magnitude DC command signal and an output terminal connected to the first coil to provide a control signal thereto for displacing the armature through reaction with the unidirectional magnetic field in accordance with the magnitude and sense of the control signal whereby the second coil is displaced with respect to the alternating magnetic field so that there is induced therein through reaction with the alternating magnetic field an AC feedback signal having a frequency correspondinG to that of the alternating magnetic field and an amplitude and phase proportional to the magnitude and direction of said displacement and through reaction with said unidirectional magnetic field a DC feedback signal having an amplitude and polarity proportional to the rate of change and direction of said displacement, and feedback means coupling the second coil to the first coil such that the AC and DC feedback signals are degeneratively combined with the command signal.

Claim 9

The apparatus of claim 5 wherein the feedback means includes means for converting the AC feedback signal to a proportional DC converted signal having a polarity determined in accordance with the phase of the AC signal relative to the alternating magnetic field, and a filter connected in parallel with the converter means, said filter operating to pass the DC feedback signal and block the AC feedback signal.

Claim 10

The apparatus of claim 6 further including means for biasing the armature means such that the indicator is held out of view against a stop affixed to the meter movement in an unenergized state of the meter movement, and level detector means connected to the output terminal of the driver means for sensing a condition whereat the signal applied to the first coil exceeds a predetermined magnitude of either polarity.

Claim 11

The apparatus of claim 6 further including level detector means connected to the output terminal of the driver means for sensing a condition whereat the signal applied to the first coil exceeds a predetermined magnitude of either polarity.

Claim 12

The apparatus of claim 8 wherein the driver means includes means for limiting its response to the DC command signal to preclude the indicator from being driven against the stop.

Claim 13

The apparatus of claim 8 further including a DC command signal source connected to the driver means, said source having a low AC output impedance, and means for coupling an AC fault detector signal to the input terminals of the driver means, said AC fault detector signal being normally short-circuited by said low AC output impedance and effective to provide a signal at the output of the driver means in excess of said predetermined magnitude upon the occurrence of an open circuit in the connection between the driver means and the DC command signal source.

Claim 14

The apparatus of claim 10 wherein the driver means includes means for limiting its response to the DC command signal.

Claim 15

The apparatus of claim 11 wherein the DC command signal source is a flight director computer and further including a flag meter comprising an actuator and warning flag coupled to the level detector means, the actuator being responsive to a signal from the level detector means for displaying the warning flag when the control signal exceeds said predetermined magnitude.

Claim 16

The apparatus of claim 12 further including means connecting the flight director computer to the flag meter actuator for displaying the warning flag upon occurrence of failure in the flight director computer.