Back to results
US 8,804,265 B2Granted
Calibration of a resonance frequency filter
AssigneeRohm Co., Ltd.
InventorsYoshito Otaguro, Shinichi Miura
Life of this patent
Estimating the term…
Abstract
Calibrating a frequency filter includes applying a series of input electrical signals at different frequencies to a shock sensor, using circuitry to identify a particular one of the frequencies as a resonance frequency of the shock sensor based on responses of the shock sensor to the series of input signals, and setting a center frequency of the notch filter equal to the particular frequency identified as the resonance frequency of the shock sensor.
Claims34
A method of calibrating a frequency filter, the method comprising:
- applying a series of input electrical signals at different frequencies to a shock sensor;
- using control circuitry to identify a particular one of the frequencies as a resonance frequency of the shock sensor based on responses of the shock sensor to the series of input signals, wherein using the control circuitry to identify the particular frequency comprises amplifying an output of the shock sensor with an amplifier that operates only during a calibration mode of the frequency filter;
- and
- setting a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the shock sensor.
1 more element
A resonance frequency filter calibration circuit comprising:
- a control circuit electrically couplable to a notch filter and to a shock sensor, wherein the control circuit comprises an amplifier and is operable to:
- apply a series of input electrical signals at different frequencies to the shock sensor;
- identify a particular one of the frequencies as a resonance frequency of the shock sensor based on responses of the shock sensor to the series of input signals;
- and
- set a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the shock sensor,
- wherein the amplifier is operable to amplify an output of the shock sensor only during a calibration mode of a frequency filer.
3 more elements
A hard disk drive comprising:
- an impact sensor;
- a notch filter;
- and
- a resonance frequency calibration circuit comprising an amplifier, wherein the calibration circuit is operable to calibrate the notch filter by:
- applying a series of input electrical signals at different frequencies to the impact sensor;
- using circuitry to identify a particular one of the frequencies as a resonance frequency of the impact sensor based on responses of the impact sensor to the series of input signals;
- and
- setting a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the impact sensor;
- and wherein the amplifier is operable to amplify an output of the impact sensor only during calibration of the notch filter.
6 more elements
A method of calibrating a frequency filter, the method comprising:
- applying a series of input electrical signals at different frequencies to a shock sensor;
- using circuitry to identify a particular one of the frequencies as a resonance frequency of the shock sensor based on responses of the shock sensor to the series of input signals;
- and
- setting a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the shock sensor,
- wherein, for each input electrical signal, using the circuitry comprises:
- averaging an amplitude of a corresponding output signal from the shock sensor to obtain an averaged amplitude;
- comparing the averaged amplitude to a reference amplitude to determine whether a measurement criteria is achieved;
- when the measurement criteria is achieved, setting a new reference amplitude equal to the averaged amplitude and setting a new resonant frequency equal to the frequency of the input signal;
- and when the measurement criteria is not achieved, maintaining the reference amplitude and the resonant frequency equal to a previously defined reference amplitude and resonant frequency, respectively.
6 more elements
A resonant frequency filter calibration circuit comprising:
- a control circuit electrically couplable to a notch filter and to a shock sensor, wherein the control circuit is operable to:
- apply a series of input electrical signals at different frequencies to the shock sensor;
- identify a particular one of the frequencies as a resonance frequency of the shock sensor based on responses of the shock sensor to the series of input signals;
- and
- set a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the shock sensor, and wherein, for each input electrical signal, the control circuit is operable to:
- average an amplitude of a corresponding output signal from the shock sensor to obtain an averaged amplitude;
- compare the averaged amplitude to a reference amplitude to determine whether a measurement criteria is achieved;
- when the measurement criteria is achieved, set a new reference amplitude equal to the averaged amplitude and set a new resonance frequency equal to the frequency of the input signal;
- and
- when the measurement criteria is not achieved, maintain the reference amplitude and the resonant frequency equal to a previously defined reference amplitude and resonant frequency, respectively.
7 more elements
A hard disk drive comprising:
- an impact sensor;
- a notch filter;
- and
- a resonance frequency calibration circuit operable to calibrate the notch filter, wherein calibration of the filter comprises:
- applying a series of input electrical signals at different frequencies to the impact sensor;
- using circuitry to identify a particular one of the frequencies as a resonance frequency of the impact sensor based on responses of the impact sensor to the series of input signals;
- and
- setting a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the impact sensor, wherein, for each input electrical signal applied to the impact sensor, the resonance frequency calibration circuit is further operable to perform operations comprising:
- averaging an amplitude of a corresponding output signal from the impact sensor to obtain an averaged amplitude;
- comparing the averaged amplitude to a reference amplitude to determine whether a measurement criteria is achieved;
- when the measurement criteria is achieved, setting a new reference amplitude equal to the averaged amplitude and setting a new resonance frequency equal to the frequency of the input signal;
- and
- when the measurement criteria is not achieved, maintaining the reference amplitude and the resonant frequency equal to a previously defined reference amplitude and resonant frequency, respectively.
10 more elements
A method of calibrating a frequency filter, the method comprising:
- applying a series of input electrical signals at different frequencies to a shock sensor;
- identifying a particular one of the frequencies as a resonance frequency of the shock sensor based on responses of the shock sensor to the series of input signals,
- wherein identifying the particular frequency comprises using an amplifier that operates only during a calibration mode of the frequency filter to amplify an output signal of the shock sensor, measuring a corresponding absolute value of the amplified output signal from the shock sensor at a plurality of different times for each input signal applied to the shock sensor, identifying a measured output signal having a minimum or maximum amplitude, and identifying a frequency of an input electrical signal that results in the output signal having the minimum or maximum amplitude as the resonance frequency of the shock sensor;
- and
- setting a center frequency of a notch filter equal to the particular frequency identified as the resonance frequency of the shock sensor.
2 more elements
Dependencies are inferred from the claim text.