Torquer scale factor temperature correction means

Claim 1

In a system for measuring an applied input function having a torque-to-balance feedback servo loop, said loop including a torquer having a permanent magnet and a driving coil magnetically coupled thereto, the resistance of said coil being a linear function of temperature over a predetermined temperature range, said coil being connected in series to a substantially low temperature coefficient resistor, wherein the measure of an applied input function is equal to the product of a torquer scale factor and a drive current passing through said coil, said torquer scale factor being a linear function of the temperature of said torquer over said temperature range, the improvement comprising: a generating means connected to said torquer driving coil and said resistor for generating an output signal representative of said applied input function, said output signal being substantially independent of the temperature variation of said torquer scale factor over said temperature range wherein said generating means includes a weighted sum network having first and second input terminals and an output terminal, said second input terminal being connected to the junction point of one terminal of said coil and one terminal of said resistor, said first input terminal being connected to the terminal at the opposite end of said coil from said junction point, and wherein said output signal at said output terminal is proportional to a weighted sum of the voltages across said first and second input terminals, said output signal and said voltages being measured with respect to the terminal at the opposite end of said resistor from said junction point.