×

Pseudosinusoidal oscillator drive system

  • US 4,727,752 A
  • Filed: 02/04/1987
  • Issued: 03/01/1988
  • Est. Priority Date: 02/04/1987
  • Status: Expired due to Fees
First Claim
Patent Images

1. An accelerometer for measuring acceleration along a sensitive axis, comprising:

  • a support;

    a proof mass;

    mounting means for mounting the proof mass to the support such that the proof mass can undergo movement relative to the support along the sensitive axis; and

    a transducer for reacting to said movement by producing a signal indicative of acceleration along the sensitive axis, the transducer including;

    (a) a resonator comprising a piezoelectric crystal connected between the proof mass and the support and constructed to undergo mechanical vibration at a frequency f that varies with the force applied to the crystal in response to an electrical drive signal having a harmonic component at frequency f, and means for producing an electrical resonator signal corresponding to said mechanical vibration; and

    (b) drive circuit means including means for receiving the resonator signal and for producing the drive signal in the form of a periodic pseudosinusoidal staircase function at a fundamental frequency f, the staircase function having N steps and M discrete nonzero amplitude levels per period, M and N being integers greater than 1 with M being less than N, the circuit means including means for producing the M amplitude levels such that predetermined harmonics of the fundamental frequency f are not present in the drive signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×