Title of Invention

A METHOD FOR INTIALIZING A DRIVE CIRCUIT

Abstract

A method for initializing a drive circuit which generates drive signals that are applied to a driver (104, 204) that is oscillating a flow tube (103A, 103B, 201), said method comprising the steps of: applying (401) said drive signals to said driver (104, 204) at a predetermined gain to initiate vibrating of said flow tube (103A, 103B,' 201); characterized by controlling (402) a drive voltage of said drive signals applied to said driver (104, 204) to maintain a velocity of pick-off signals received from pick-off sensors (105, 105'; 205, 205') associated with said flow tube (103A, 103B, 201); determining (403) whether a notch filter has converged on a drive frequency of said flow tube (103A, 103B, 201) based on said pick -off signals; and controlling (404) said drive voltage of said drive signals applied to said driver (104, 204) to maintain a displacement of said flow tube (103A, 103B, 201) in response to a determination that said notch filter has converged on said drive frequency.

Full Text

WE CLAIM : 1. A method for initializing a drive circuit which generates drive signals that are applied to a driver (104, 204) that is oscillating a flow tube (103A, 103B, 201), said method comprising the steps of: applying (401) said drive signals to said driver (104, 204) at a predetermined gain to initiate vibrating of said flow tube (103A, 103B, 201); controlling (402) a drive voltage of said drive signals applied to said driver (104, 204) to maintain a velocity of pick-off signals received from pick-off sensors (105, 105'; 205, 205') associated with said flow tube (103A, 103B, 201); determining (403) whether a notch filter has converged on a drive frequency of said flow tube (103A, 103B, 201) based on said pick-off signals; and controlling (404) said drive voltage of said drive signals applied to said driver (104, 204) to maintain a displacement of said flow tube (103A, 103B, 201) in response to a determination that said notch filter has converged on said drive frequency. 2. The method as claimed in claim 1, comprising the steps of: comparing said drive frequency to a threshold frequency; determining said flow tube (103A, 103B, 201) is a straight tube (201) responsive to said drive frequency being greater than said threshold frequency; and determining said flow tube (103A, 103B, 201) is a curved flow tube (103A, 103B) responsive to said drive frequency being less than or equal to said threshold frequency. 3. The method as claimed in claim 1, wherein said step of applying (401) said drive signals to said driver (104, 204) to initiate vibrating of said flow tube (103A, 103B,201) comprises the step of: initializing said notch filter. 4. The method as claimed in claim 1 comprising the steps of: determining (804) whether said notch filter has converged to a notch filter value that is within a desired range; and returning (810) to said step of applying (401) drive signals to said driver (104, 204) responsive to a determination that said notch filter value is outside said desired range. 5. The method as claimed in claim 4, wherein said step of determining whether said notch filter value is within said desired range comprises the step of: comparing said notch filter value to a minimum value and a maximum value. 6. The method as claimed in claim 1, wherein said step of applying (401) said drive signals to said driver (104, 204) to initiate vibrating of said flow tube (103A, 103B, 201) comprises the steps of: setting (703) amplitudes of said drive signals to initial amplitudes; setting (704) an initial application time of said drive signals; and applying (706) said drive signals to said driver (104, 204) for a duration of said application time. 7. The method as claimed in claim 6, wherein said step of applying (401) said drive signals to said driver (104, 204) to initiate vibrating of said flow tube (103A, 103B,201) comprises the steps of: determining (707) whether amplitudes of said pick-off signals are sufficient for said notch filter; adjusting (708) said amplitudes of said drive signals in response to a determination that said amplitudes of said pick-off signals are not sufficient for said notch filter; and adjusting (709) said application time in response to a determination that said amplitudes of said drive signals are not sufficient. 8. The method as claimed in claim 1, wherein said step of controlling (404) said drive voltage of said drive signals applied to said driver (104, 204) to maintain said displacement comprises the steps of: setting (1101) a programmable gain amplitude; generating (1103) said drive signals to maintain an amplitude of said pick-off signals from said pick-off sensors (105, 105' ; 205, 205') associated with said flow tube (103A, 103B,201); determining (1104) whether said amplitude of said pick-off signals is maintained; and performing (1105) a forgive process in response to said amplitude of said pick-off signals not being maintained. 9. The method as claimed in claim 1 comprising the step of: determining (803) flowmeter sensor parameters in response to a determination said notch filter has converged upon said drive frequency. 10. The method as claimed in claim 9, wherein said step of determining (803) said flowmeter sensor parameters comprises the step of: determining (901) a proportional gain of said drive signals applied to said driver (104, 204). 11. The method as claimed in claim 9, wherein said step of determining (803) said flowmeter sensor parameters comprises the step of: determining (902) an integral gain of said drive signals applied to said driver (104, 204). 12. The method as claimed in claim 1, wherein said step of controlling (404) said drive voltage of said drive signals applied to said driver (104, 204) to maintain said displacement comprises the step of: testing (1000) to determine whether a drive loop gain is locked.

Documents:

in-pct-2002-che1441-claims duplicate.pdf

in-pct-2002-che1441-claims original.pdf

in-pct-2002-che1441-correspondance others.pdf

in-pct-2002-che1441-correspondance po.pdf

in-pct-2002-che1441-description complete duplicate.pdf

in-pct-2002-che1441-description complete original.pdf

in-pct-2002-che1441-drawings.pdf

in-pct-2002-che1441-form 1.pdf

in-pct-2002-che1441-form 26.pdf

in-pct-2002-che1441-form 3.pdf

in-pct-2002-che1441-form 5.pdf

in-pct-2002-che1441-other documents.pdf

in-pct-2002-che1441-pct.pdf