Method of deriving a frequency of a pulse signal from alternate sources and method of calibrating same
AssigneeLandis+Gyr, Inc.
InventorsKurt Bammert, Mirko Bulinsky, Michel Schaller
Life of this patent
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Abstract
A method derives a frequency of a pulse signal from a line frequency. The method includes measuring a period of a line frequency pulse signal having the line frequency using a measured frequency derived from an oscillator frequency. The method further includes determining if the period of the line frequency pulse signal is within a predetermined tolerance limit. The line frequency is used to derive the frequency of the pulse signal when the period is determined to be within the predetermined tolerance limit, and the oscillator frequency is used to derive the frequency of the pulse signal when the period is determined to be outside the predetermined tolerance limit.
Claims17
A method for deriving a frequency of a pulse signal from a line frequency, the method comprising:
- a) measuring a period of a line frequency pulse signal having the line frequency using a measured frequency derived from an oscillator frequency;
- b) determining if the period of the line frequency pulse signal is within a predetermined tolerance limit;
- c) using the line frequency to derive the frequency of the pulse signal when the period is determined to be within the predetermined tolerance limit;
- and
- d) using the oscillator frequency to derive the frequency of the pulse signal when the period is determined to be outside the predetermined tolerance limit.
A method of calibrating a frequency of a pulse signal which is derived from an oscillator frequency, the method comprising:
- a) determining a frequency correction value with the aid of a reference frequency;
- b) storing the frequency correction value in a memory;
- and
- c) generating from a base frequency an approximately halved base frequency using an approximation derived from the frequency correction value, and using the approximately halved base frequency to generate the calibrated frequency derived from the oscillator frequency.
A method for deriving a frequency of a pulse signal from a line frequency, the method comprising:
- a) measuring a period of a line frequency pulse signal having the line frequency using a measured frequency derived from an oscillator frequency, said measuring performed within at least one of a group consisting of an electricity meter, a supply meter, and a ripple control meter.
- b) determining if the period of the line frequency pulse signal is within a predetermined tolerance limit;
- c) using the line frequency to derive the frequency of the pulse signal when the period is determined to be within the predetermined tolerance limit;
- and
- d) using the oscillator frequency to derive the frequency of the pulse signal when the period is determined to be outside the predetermined tolerance limit.
Dependencies are inferred from the claim text.