Electrical measuring device

Claim 2

An electrical measuring device including means responsive to a condition to be measured for generating an electric output having a magnitude dependent upon the magnitude of the condition to be measured, meter control means connected so as to receive the electric output and to produce a resultant magnetic field the angular displacement of which corresponds to the magnitude of the condition to be measured, permanent magnet armature means responsive to the resultant magnetic field so as to align itself therewith, indicator means positionable by the armature means and suitably calibrated so as to indicate the magnitude of the condition to be measured, and error compensation means connected to the armature means so as to be responsive to the position of the armature means and connected to the means responsive to the said condition for varying the electric output of the means responsive to the condition to be measured to compensate for known nonlinearities in the meter control means and in the response to the resultant magnetic field by the armature means.

Claim 3

The electrical measuring device in Claim 1, wherein the error compensation means includes a potentiometer electrically connected to the means responsive to a condition to be measured and having a wiper arm effectively connected to the permanent magnet armature so as to be rotated thereby.

Claim 4

An electrical measuring device including means responsive to a condition to be measured for generating an electric output having a magnitude dependent upon the magnitude of the condition to be measured; meter control means connected so as to receive the electric output of the means responsive to a condition to be measured and to produce a resultant magnetic field the angular displacement of which corresponds to the magnitude of the condition to be measured, the meter control means including first and second coil means for producing first and second magnetic field components along first and second axes respectively, a source of electric power for supplying current to the first and second coil means, first current control means responding to the electric output of the means responsive to a condition to be measured and controlling current through the first coil means in a manner such that the magnitude of the first magnetic field component decreases with an increase in the magnitude of the condition to be measured, and second current control means responding to the control of the current through the first coil means and controlling the current through the second coil means in a manner such that the magnitude of the second magnetic field component increases with a decrease in the magnitude of the first magnetic field component so as to produce a change in the angular displacement of the resultant magnetic field so as to correspond to the magnitude of the condition to be measured; permanent magnet armature means responsive to the resultant magnetic field so as to align itself therewith; indicator means positionable by the permanent magnet armature means and suitably calibrated so as to indicate the magnitude of the condition to be measured; and error compensation means including a potentiometer having a resistance portion connected to the means responsive to the condition to be measured and having a wiper arm effectively connected to the permanent magnet armature so as to be rotated thereby so as to vary the electric output of the means responsive to a condition to be measured to compensate for known nonlinearities in the meter control means and in the response to the resultant magnetic field by the permanent magnet armature.

Claim 5

An electrical measuring device including means responsive to a condition to be measured for generating an electric output having a magnitude dependent upon the magnitude of the condition to be measured; meter control means connected so as to receive the electric output of the means responsive to a condition to be measured and to produce a resultant magnetic field the angular displacement of which corresponds to the magnitude of the condition to be measured, the meter control means including first and second coil means for producing first and second magnetic field components along first and second axes respectively, a source of electric power for supplying current to the first and second coil means, first current control means responding to the electric output of the means responsive to a condition to be measured and controlling current through the first coil means in a manner such that the magnitude of the first magnetic field component decreases with an increase in the magnitude of the condition to be measured, and second current control means responding to the control of the current through the first coil means and controlling the current through the second coil means in a manner such that the magnitude of the second magnetic field component increases with a decrease in the magnitude of the first magnetic field component so as to produce a change in the angular displacement of the resultant magnetic field so as to correspond to the magnitude of the condition to be measured; permanent magnet armature means responsive to the resultant magnetic field so as to align itself therewith; indicator means positionable by the permanent magnet armature means and suitably calibrated so as to indicate the magnitude of the condition to be measured; and error compensation means including a potentiometer having a resistance portion connected to the means responsive to the condition to be measured and having a wiper arm effectively connected to the permanent magnet armature so as to be rotated thereby so as to vary the electric output of the means responsive to a condition to be measured to compensate for known nonlinearities in the meter control means and in the response to the resultant magnetic field by the permanent magnet armature.

Claim 6

The electrical measuring device in Claim 3 wherein the first and second axes are at right angles.

Claim 7

An electrical measuring device for indicating The rate of occurrence of an event including means producing a series of voltage pulses the frequency of which corresponds to the rate of occurrence of the event, tachometer means for generating an electric output having a magnitude dependent upon the frequency of the series of voltage pulses, meter control means connected so as to receive the electric output and to produce a resultant magnetic field the angular displacement of which corresponds to the rate of occurrence of the event, permanent magnet armature means responsive to the resultant magnetic field so as to align itself therewith, indicator means positionable by the permanent magnet armature means and suitably calibrated so as to indicate the rate of occurrence of the event and error compensation means connected to the armature means so as to be responsive to the position of the armature means and connected to the tachometer means for varying the electric output of the tachometer means to compensate for known nonlinearities in the meter control means and the response to the resultant magnetic field by the permanent armature.

Claim 8

An electrical measuring device for indicating The rate of occurrence of an event including means producing a series of voltage pulses the frequency of which corresponds to the rate of occurrence of the event, tachometer means for generating an electric output having a magnitude dependent upon the frequency of the series of voltage pulses, meter control means connected so as to receive the electric output and to produce a resultant magnetic field the angular displacement of which corresponds to the rate of occurrence of the event, permanent magnet armature means responsive to the resultant magnetic field so as to align itself therewith, indicator means positionable by the permanent magnet armature means and suitably calibrated so as to indicate the rate of occurrence of the event and error compensation means connected to the armature means so as to be responsive to the position of the armature means and connected to the tachometer means for varying the electric output of the tachometer means to compensate for known nonlinearities in the meter control means and the response to the resultant magnetic field by the permanent armature.