| 摘要 |
A system for converting analog torquer current to digital form is based on a current-controlled oscillator, preferably a YIG-tuned microwave oscillator, which produces an output frequency characterized by a nominally constant bias frequency term subject to drift and a tuning frequency term proportional to input current. An automatic calibration circuit gates the input current ON and OFF at a relatively low constant sampling rate. The number of cycles of the high frequency oscillator output is counted separately for the ON and OFF periods. The difference between the ON and OFF period counts is proportional to the input current and independent of the bias frequency. The system is specifically designed for converting analog torquer currents in inertial instruments to computer-compatible form.
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