Electronic peak sensing digitizer for optical tachometers

Claim 3

The method of digitizing a signal as defined in claim 1 wherein said step of delaying the reamplified signal may be varied from 0° to 180° depending on the value of impedance that is used.

Claim 4

The method of digitizing a signal as defined in claim 2 wherein said step of subtracting the delayed signal from the reamplified signal is effective to vary the delay of the resultant signal to a degree proportional to said impedance that is used.

Claim 5

An improved system for digitizing a high frequency sinusoidal signal from an optical tachometer comprising: a. a differential amplifier coupled to said optical tachometer by a signal carrying line and a non-signal carrying line, said non-signal carrying line being subtracted from the signal carrying line such that the amplified output therefrom is a high gain signal having substantially reduced line-induced noise, b. a low pass filter coupled to said differential amplifier and effective for filtering out high frequency noise components, c. a buffer amplifier coupled to said filter and effective for reamplifying the filtered signal to compensate for gain losses incurred in said filter, d. an artifical delay line coupled to said buffer amplifier and effective for delaying the reamplified signal and for subtracting the delayed signal from the undelayed signal to thereby produce a uniformly delayed resultant signal through time such that the zero amplitude points thereof delayably concur just after the peak points of the reamplified signal, e. a comparator coupled to said buffer amplifier and to said delay line and effective for digitizing said resultant signal when the slope direction thereof as sensed thereby is opposite the preceding one, said comparator being operative also to not digitize said resultant signal when the slope direction thereof is identical to said preceding one, and f. a pair of pulse generators parallely coupled to said comparator and effective for trigger pulsing on the positive and negative peaks, respectively, of said resultant signal and for outputting signals to an OR gate to thereby effectively double the frequency of said original sinusoidal signal.

Claim 6

An improved system for digitizing a high frequency sinusoidal signal from an optical tachometer comprising: a. a differential amplifier coupled to said optical tachometer by a signal carrying line and a non-signal carrying line, said non-signal carrying line being subtracted from the signal carrying line such that the amplified output therefrom is a high gain signal having substantially reduced line-induced noise, b. a low pass filter coupled to said differential amplifier and effective for filtering out high frequency noise components, c. a buffer amplifier coupled to said filter and effective for reamplifying the filtered signal to compensate for gain losses incurred in said filter, d. an artifical delay line coupled to said buffer amplifier and effective for delaying the reamplified signal and for subtracting the delayed signal from the undelayed signal to thereby produce a uniformly delayed resultant signal through time such that the zero amplitude points thereof delayably concur just after the peak points of the reamplified signal, e. a comparator coupled to said buffer amplifier and to said delay line and effective for digitizing said resultant signal when the slope direction thereof as sensed thereby is opposite the preceding one, said comparator being operative also to not digitize said resultant signal when the slope direction thereof is identical to said preceding one, and f. a pair of pulse generators parallely coupled to said comparator and effective for trigger pulsing on the positive and negative peaks, respectively, of said resultant signal and for outputting signals to an OR gate to thereby effectively double the frequency of said original sinusoidal signal.

Claim 7

The improved system for digitizing a high frequency sinusoidal signal defined in claim 4 wherein said artifical delay line is operative to cause a delay in the resultant signal that is proportional to the impedance that is used.

Claim 8

The improved system for digitizing a high frequency sinusoidal signal defined in claim 4 wherein each of said pair of pulse generators is a single shot multivibrator.

Claim 9

The improved system for digitizing a high frequency sinusoidal signal defined in claim 6 wherein an inverter is interposed between said comparator and said pulse generator for trigger pulsing on said negative peaks of said resultant signal, whereby said generator would be rendered effective for triggering pulses on the psuedo positive peaks of said resultant signal.

Claim 10

A high frequency digitizing device for measuring the speed of a rotating shaft, said device comprising a transducer operatively coupled to said shaft, a differential amplifier coupled to said transducer for removing line induced noise and for amplifying the signal received from said transducer, a filter coupled to said differential amplifier for removing high frequency noise from the signal produced by said differential amplifier, a buffer amplifier coupled to said filter for replacing the gain that is lost in said filter, an artifical delay line coupled to said buffer amplifier for delaying the output therefrom and for subtracting the delayed signal from the undelayed signal to thereby produce a delayed resultant signal, a comparator for digitizing said resultant signal, a pair of pulse generators coupled in parallel to said comparator and effective for triggering on the positive and negative peaks of the comparator's output signal, and an OR gate coupled to said pair of pulse generators whereby the outputs thereof are ORed together to double the frequency of the signal received from said transducer, said artifical delay line being characterized by an impedance that depending on its value will be operative to proportionally effect a phase shift delay of the buffer amplifier signal thereby enabling the device to carry out a delayed peak detection of the input signal using zero-crossing detection of the resultant signal.

Claim 11

A high frequency digitizing device for measuring the speed of a rotating shaft, said device comprising a transducer operatively coupled to said shaft, a differential amplifier coupled to said transducer for removing line induced noise and for amplifying the signal received from said transducer, a filter coupled to said differential amplifier for removing high frequency noise from the signal produced by said differential amplifier, a buffer amplifier coupled to said filter for replacing the gain that is lost in said filter, an artifical delay line coupled to said buffer amplifier for delaying the output therefrom and for subtracting the delayed signal from the undelayed signal to thereby produce a delayed resultant signal, a comparator for digitizing said resultant signal, a pair of pulse generators coupled in parallel to said comparator and effective for triggering on the positive and negative peaks of the comparator's output signal, and an OR gate coupled to said pair of pulse generators whereby the outputs thereof are ORed together to double the frequency of the signal received from said transducer, said artifical delay line being characterized by an impedance that depending on its value will be operative to proportionally effect a phase shift delay of the buffer amplifier signal thereby enabling the device to carry out a delayed peak detection of the input signal using zero-crossing detection of the resultant signal.