Calibration of signal feedback through VCO's

Claim 1

A calibration system for a signal monitoring system wherein a plurality of variable amplitude signals are converted to corresponding variable frequency signals: a plurality of voltage controlled oscillators (VCO) each connected for receiving a respective one of a plurality of variable amplitude signals; a multiplexor having a plurality of input terminals, each of the plurality of variable amplitude signals being coupled to a respective one of the input terminals of the multiplexor; a calibration VCO having an input terminal connected to an output terminal of the multiplexor; a predefined calibration signal coupled to one of the input terminals of said multiplexor; processor means, coupled for receiving variable frequency signals from each of said VCO's, for converting each of the variable frequency signals into system usable signals representative of each of the variable amplitude signals, the processor means further comprising means for selectively switching the variable amplitude signals and the calibration signal to the output terminal of the multiplexor and for comparing a signal from the calibration VCO to a signal from a corresponding one of the plurality of VCO's, the processor means correcting the system variable signals to compensate for any difference with respect to the calibration VCO signal.

Claim 8

A method for calibrating a primary signal processor without interruption of signal processing using a calibration signal processor, the method comprising the steps of: processing a calibration reference signal through the calibration signal processor for developing a calibration signal; comparing the calibration signal to a predetermined calibration signal; determining a multiplier necessary to equate the calibration signal to the predetermined calibration signal; processing a signal substantially simultaneously through both the primary signal processor and the calibration signal processor; multiplying the signal processed through the calibration signal processor by the determined multiplier; comparing the signal obtained by the step of multiplying to the signal processed through the primary signal processor; computing a factor necessary to equate the signal processed through the primary signal processor to the signal obtained by the step of multiplying; and adjusting each signal processed through the primary signal processor by the computed factor.

Claim 9

A method for calibrating a primary signal processor without interruption of signal processing using a calibration signal processor, the method comprising the steps of: processing a calibration reference signal through the calibration signal processor for developing a calibration signal; comparing the calibration signal to a predetermined calibration signal; determining a multiplier necessary to equate the calibration signal to the predetermined calibration signal; processing a signal substantially simultaneously through both the primary signal processor and the calibration signal processor; multiplying the signal processed through the calibration signal processor by the determined multiplier; comparing the signal obtained by the step of multiplying to the signal processed through the primary signal processor; computing a factor necessary to equate the signal processed through the primary signal processor to the signal obtained by the step of multiplying; and adjusting each signal processed through the primary signal processor by the computed factor.

Claim 10

A method for calibrating a primary signal processor subject to drift, without interruption of signal processing, using a calibrated signal processor, the method comprising the steps of: processing a signal substantially simultaneously through both the primary signal processor and the calibration signal processor to obtain at least two resulting signals; comparing the resulting signals and; if the resulting signals differ, developing a multiplier for equating the resulting signal from the primary signal processor to the resulting signal from the calibration signal processor.

Claim 11

A method for calibrating a primary signal processor subject to drift, without interruption of signal processing, using a calibrated signal processor, the method comprising the steps of: processing a signal substantially simultaneously through both the primary signal processor and the calibration signal processor to obtain at least two resulting signals; comparing the resulting signals and; if the resulting signals differ, developing a multiplier for equating the resulting signal from the primary signal processor to the resulting signal from the calibration signal processor.

Claim 13

A system for calibration of a signal processor without interruption of signal processing through the processor, the system comprising; first voltage to frequency converter means having an input for receiving an analog signal and an output for producing an oscillating signal having a frequency corresponding to the amplitude of the analog signal; first counter means having an input coupled to the output of the converter means, the counter means providing a digital representation of the frequency of the oscillating signal; second voltage to frequency converter means having an input for receiving an analog signal and an output for producing an oscillating signal having a frequency corresponding to the amplitude of the analog signal; second counter means having an input coupled to the output of the second converter means, the second counter means providing a digital representation of the frequency of the oscillating signal; a precision analog reference signal selectively coupled to the second converter means for calibration thereof; and switch means for selectively coupling the precision reference signal and the analog signal applied to the input of the first converter means to the second converter means whereby the output of the first counter means can be compared to the output of the second counter means for calibration of the signal processor comprising the first converter means and the first counter means.

Claim 14

A system for calibration of a signal processor without interruption of signal processing through the processor, the system comprising; first voltage to frequency converter means having an input for receiving an analog signal and an output for producing an oscillating signal having a frequency corresponding to the amplitude of the analog signal; first counter means having an input coupled to the output of the converter means, the counter means providing a digital representation of the frequency of the oscillating signal; second voltage to frequency converter means having an input for receiving an analog signal and an output for producing an oscillating signal having a frequency corresponding to the amplitude of the analog signal; second counter means having an input coupled to the output of the second converter means, the second counter means providing a digital representation of the frequency of the oscillating signal; a precision analog reference signal selectively coupled to the second converter means for calibration thereof; and switch means for selectively coupling the precision reference signal and the analog signal applied to the input of the first converter means to the second converter means whereby the output of the first counter means can be compared to the output of the second counter means for calibration of the signal processor comprising the first converter means and the first counter means.