Frequency measurement system

Claim 1

A method of providing an output signal having a value representative of the anticipated instantaneous frequency of an alternating signal comprising the steps: (a) determining the apparent frequency of said alternating current signal at the end of a half cycle of said alternating current signal; (b) deriving from successively determined apparent frequencies a rate of change in frequency; and, (c) developing said output signal as a function of the last determined apparent frequency and a last determined rate of change in frequency.

Claim 2

A method of providing an output signal having a value representative of the anticipated instantaneous frequency of an alternating signal comprising the steps: (a) determining the apparent frequency of said alternating current signal at the end of a half cycle of said alternating current signal; (b) deriving from successively determined apparent frequencies a rate of change in frequency; and, (c) developing said output signal as a function of the last determined apparent frequency and a last determined rate of change in frequency.

Claim 6

A method of developing an output signal having a value representative of the instantaneous frequency of an alternating current signal comprising the steps: (a) respectively developing first and second count values representing respectively a time said alternating current signal exists in alternate half cycles; (b) determining the apparent frequency of said alternating current signal at the end of a half cycle as a function of the last said developed count and a value representing an anticipated rate of change in frequency; (c) deriving said value representing the anticipated rate of change as a function of two successively determined apparent frequencies; and, (d) developing said output signal as a function of said last developed apparent frequency and the last determined value representing rate of change.

Claim 7

A method of developing an output signal having a value representative of the instantaneous frequency of an alternating current signal comprising the steps: (a) respectively developing first and second count values representing respectively a time said alternating current signal exists in alternate half cycles; (b) determining the apparent frequency of said alternating current signal at the end of a half cycle as a function of the last said developed count and a value representing an anticipated rate of change in frequency; (c) deriving said value representing the anticipated rate of change as a function of two successively determined apparent frequencies; and, (d) developing said output signal as a function of said last developed apparent frequency and the last determined value representing rate of change.

Claim 12

A method of measuring the frequency of an alternating current signal comprising the steps: (a) repetitively developing first and second count values representing respectively the times that the alternating current signal exists in alternate half cycles; (b) retaining the last fully developed count value representing the last fully completed half cycle while developing a count value representing the extant half cycle; (c) periodically examining each of said count values to determine the completion of a half cycle; (d) determining from a just completed count value the average frequency of said alternating current signal for a just completed half cycle; (e) deriving an actual frequency signal for a just completed half cycle by combining said average frequency signal with a change signal representing approximately one-half of a predicted frequency change between said just completed half cycle and intermediately preceding completed half cycle; and (f) determining said change signal by calculating the rate of change in frequency between said just completed half cycle and the half cycle completed immediately therebefore.

Claim 13

A method of measuring the frequency of an alternating current signal comprising the steps: (a) repetitively developing first and second count values representing respectively the times that the alternating current signal exists in alternate half cycles; (b) retaining the last fully developed count value representing the last fully completed half cycle while developing a count value representing the extant half cycle; (c) periodically examining each of said count values to determine the completion of a half cycle; (d) determining from a just completed count value the average frequency of said alternating current signal for a just completed half cycle; (e) deriving an actual frequency signal for a just completed half cycle by combining said average frequency signal with a change signal representing approximately one-half of a predicted frequency change between said just completed half cycle and intermediately preceding completed half cycle; and (f) determining said change signal by calculating the rate of change in frequency between said just completed half cycle and the half cycle completed immediately therebefore.

Claim 15

A method of providing an output signal representative of the instantaneous rotational speed of a rotating motor comprising the steps: (a) generating an alternating current signal representative of said rotational speed, said alternating signal having substantially equal relatively negative and positive alternating sampling periods when said motor speed is constant; (b) repetitively developing first and second signals representing, respectively, the time periods of said negative and positive time periods; (c) retaining the last fully developed of said first and second signals while developing the other thereof; (d) periodically examining each of said first and second signals to determine the completion of a sampling period; (e) determining from a just fully developed of such signals an average speed signal indicative of the average motor speed during the just complete sampling period; (f) deriving an actual speed signal at the end of each sampling period by combining an average speed signal with a change signal representative of an anticipated change in speed of said motor during the first completed sampling period; (g) deriving said change signal as a function of the two immediately preceding derived actual speed signals; and, (h) generating said output signal for each sampling period by first utilizing the last derived actual speed signal and then periodically adjusting said output signal by a delta signal representing the anticipated change in motor speed since the time of the last adjustment.

Claim 16

A method of providing an output signal representative of the instantaneous rotational speed of a rotating motor comprising the steps: (a) generating an alternating current signal representative of said rotational speed, said alternating signal having substantially equal relatively negative and positive alternating sampling periods when said motor speed is constant; (b) repetitively developing first and second signals representing, respectively, the time periods of said negative and positive time periods; (c) retaining the last fully developed of said first and second signals while developing the other thereof; (d) periodically examining each of said first and second signals to determine the completion of a sampling period; (e) determining from a just fully developed of such signals an average speed signal indicative of the average motor speed during the just complete sampling period; (f) deriving an actual speed signal at the end of each sampling period by combining an average speed signal with a change signal representative of an anticipated change in speed of said motor during the first completed sampling period; (g) deriving said change signal as a function of the two immediately preceding derived actual speed signals; and, (h) generating said output signal for each sampling period by first utilizing the last derived actual speed signal and then periodically adjusting said output signal by a delta signal representing the anticipated change in motor speed since the time of the last adjustment.