Signal conditioner for a vibration sensor

• US 6,276,213 B1
• Filed: 12/23/1999
• Issued: 08/21/2001
• Est. Priority Date: 12/23/1999
• Status: Expired due to Fees

• Current Assignee: Maars Incorporated
• Original Assignee: Maars Incorporated
• Inventors: Humphrey, Cullen Thomas Jr., Lee, Lloyd Dewey Jr., Petersen, Kent Michael
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/471,786
• Time in Patent Office: 607 Days
• Field of Search: 735/70, 735/93, 736/59, 736/60, 736/49, 736/02, 702/35, 702/36, 702/39, 702/43, 702/189, 702/190
• US Class Current: 73/660
• CPC Class Codes: G01H 1/00 Measuring characteristics of vibrations in solids by using direct conduction to the detector G01H9/00, G01H11/00 take precedence

Abstract

A device for conditioning the electrical signal generated by a vibration sensor for use of the conditioned signal by a computer-based data acquisition system utilizes a support body and circuitry for performing a series of operations upon the sensor-generated signal. The circuitry includes an input stage for receiving and amplifying the electrical signal generated by the vibration sensor to thereby develop an output electrical signal of the input, and further includes a gain stage for receiving and AC coupling the output electrical signal of the input stage and amplifying the output signal of the input stage by a predetermined factor and thereby developing an output electrical signal of the gain stage. A integrator receives and integrates the output electrical signal developed by the gain stage, and a filter receives and filters either the output electrical signal developed by the gain stage or the output electrical signal developed by the integrator to thereby develop an output electrical signal by the filter which is free of signal frequency above a preselected frequency range. A buffer receives and amplifies the output electrical signal of the input to thereby develop an output electrical signal of the device. The device further includes a sample/hold stage at which the output signal from the buffer can be collected and frozen as a sample signal for use of the frozen signal by the data-gathering system.

Claims

1. A device for conditioning the electrical signal generated by a vibration sensor for use of the conditioned signal by a computer-based data acquisition system, the device comprising:

a support body;

input means mounted upon the support body including an impedance for receiving the electrical signal generated by the vibration sensor and across which the received signal is sensed, and the input means further including an amplifier for amplifying the electrical signal sensed across the impedance to thereby develop an output electrical signal of the input means;

gain means mounted upon the support body for receiving and AC coupling the output electrical signal of the input means and amplifying the output signal of the input means by a predetermined factor and thereby developing an output electrical signal of the gain means;

integrating means mounted upon the support body for receiving and integrating the output electrical signal developed by the gain means and thereby developing an output electrical signal of the integrating means;

filter means mounted upon the support body for receiving and filtering one of the output electrical signal developed by the gain means and the output electrical signal developed by the integrating means to thereby develop an output electrical signal by the filter means which is free of signal frequency above a preselected range, and the filter means having an adjustable setting enabling the preselected frequency range of the filter to be altered;

a conductor associated with the filter means through which frequency-setting commands are received by the filter means;

buffer means mounted on the support body for receiving and amplifying the output electrical signal of the filter means to thereby develop an output electrical signal of the buffer means;

an output conductor associated with the buffer means for enabling the output electrical signal developed by the buffer means to be conducted to a computer-based data acquisition system;

sample/hold means for receiving and freezing the output signal from the buffer means as a sample signal; and

a conductor associated with the sample/hold means through which operation of the sample/hold means is initiated.

2. The device as defined in claim 1 further comprising means for, connected between the input means and the buffer means, enabling the output electrical signal developed by the input means to be conducted directly to the buffer means without being acted upon by the gain means, integrating means or filtering means;

the buffer means includes a switch for selectively permitting either the output electrical signal developed by the filter means or the output electrical signal developed by the input means to be conducted to the output conductor associated with the buffer means; and

an additional conductor is associated with the buffer means through which a switch-setting command signal is received by the switch of the buffer means.

3. The device as defined in claim 2 wherein a setting of the switch of the buffer means is determined by a low or a high voltage state of the additional conductor associated with the buffer means.

4. The device as defined in claim 1 wherein the predetermined factor of the gain means is either 1.6 or 3.2.

5. The device as defined in claim 1 further including means for, connected between the gain means and the filter means, enabling the output electric signal developed by the gain means to be conducted directly to the filter means without being acted upon by the integrating means.

6. The device as defined in claim 1 wherein the operation of the sample/hold means is initiated by one of a low or a high voltage state of the conductor associated with the sample/hold means.

7. The device as defined in claim 1 further including a pair of conductors associated with the input means through which the electrical signal generated by a the vibration sensor is received by the input means.

8. The device as defined in claim 1 wherein the support body upon which the input means, gain means, integrating means, filter means, buffer means and sample/hold means are mounted is a circuit board and the device further includes an open-ended outer casing within which the circuit board is positioned.

9. A device for connection between a vibration sensor and a computer-based data acquisition system for conditioning the an electrical signal generated by a vibration sensor for use of the conditioned signal by the computer-based data acquisition system, the device comprising:

a support body;

input means mounted upon the support body including an impedance for receiving the electrical signal generated by a the vibration sensor and across which the received signal is sensed, and the input means further including an amplifier for amplifying the electrical signal sensed across the impedance to thereby develop an output electrical signal of the input means;

a pair of conductor pins associated with the input means through which the electrical signal generated by a the vibration sensor is received by the input means;

gain means mounted upon the support body for receiving and AC coupling the output electrical signal of the input means and then amplifying the output signal of the input means to thereby develop an output electrical signal of the gain means;

integrating means mounted upon the support body for receiving and integrating the output electrical signal developed by the gain means and thereby developing an output electrical signal of the integrating means;

filter means mounted upon the support body for receiving and filtering one of the output electrical signal developed by the gain means and the output electrical signal developed by the integrating means to thereby develop an output electrical signal by the filter means which is free of signal frequency above a preselected range, and the filter means having an adjustable setting enabling the preselected filter frequency range to be altered;

a conductor pin associated with the filter means and connectable to the computer-based data acquisition system through which frequency-setting commands are received by the filter means from the data acquisition system;

buffer means mounted upon the support body for receiving and amplifying the output electrical signal from the filter means to thereby develop an output electrical signal of the buffer means;

an output conductor pin associated With the buffer means enabling the output electrical signal to be conducted to a the computer-based data acquisition system;

means connected between the input means and the buffer means for enabling the output electrical signal developed by the input means to be conducted directly to the buffer means without being acted upon by the gain means, integrating means or filtering means;

the buffer means includes a switch for selectively permitting either the output electrical signal developed by the filter means or the output electrical signal developed by the input means to be conducted to the output conductor pin associated with the buffer means;

an additional conductor pin associated with the buffer means and connectable to the computer-based data acquisition system through which a switch-setting command signal is received by the switch of the buffer means from the data acquisition system;

sample/hold means for receiving and freezing the output electrical signal of the buffer means at a selected instant of time so that the output signal conducted to the computer-based data acquisition system by way of the output conductor pin during operation of the sample/hold means is the signal which has been frozen by the sample/hold means; and

a conductor pin associated with the sample/hold means and connectable to the computer-based data acquisition system through which the operation of the sample/hold means is initiated by the computer-based data acquisition system.

10. The device as defined in claim 9 wherein a setting of the switch of the buffer means is determined by a low or a high voltage state of the conductor pin associated with the buffer means, and wherein the high or low voltage state of the conductor pin associated with the buffer means is determined by the data acquisition system.

11. The device as defined in claim 9 wherein the gain means is adapted to amplify the output signal of the input means by a predetermined factor and the predetermined factor of the gain means is either 1.6 or 3.2.

12. The device as defined in claim 9 further including means for, connected between the gain means and the filter means, enabling the output electric signal developed by the gain means to be conducted directly to the filter means without being acted upon by the integrating means.

13. The device as defined in claim 9 wherein the operation of the sample/hold means is initiated by one of a low or a high voltage state of the conductor pin associated with the sample/hold means, and wherein the high or low voltage state of the conductor pin associated with the sample/hold means is determined by the data acquisition system.

14. The device as defined in claim 9 wherein the support body upon which the input means, gain means, integrating means, filter means, buffer means and sample/hold means are mounted is a circuit board and the device further includes an open-ended outer casing within which the circuit board is positioned and an amount of potting resin positioned within the outer casing so that the circuit board is embedded within the resin and the conducting pins extend out of the resin at the open end of the casing.

15. In combination with a signal-generating vibration sensor and a computer-based data acquisition system for analyzing signals of the vibration sensor, a device for conditioning an electrical signal generated by the vibration sensor for use of the conditioned signal by the computer-based data acquisition system, the device including:

a support body;

input means mounted upon the support body including an impedance for receiving the electrical signal generated by the vibration sensor and across which the received signal is sensed, and the input means further including an amplifier for amplifying the electrical signal sensed across the impedance to thereby develop an output electrical signal of the input means;

gain means mounted upon the support body for receiving and AC coupling the output electrical signal of the input means and amplifying the output signal of the input means by a predetermined factor and thereby developing an output electrical signal of the gain means;

integrating means mounted upon the support body for receiving and integrating the output electrical signal developed by the gain means and thereby developing an output electrical signal of the integrating means;

filter means mounted upon the support body for receiving and filtering one of the output electrical signal developed by the gain means and the output electrical signal developed by the integrating means to thereby develop an output electrical signal by the filter means which is free of signal frequency above a preselected range, and the filter means having an adjustable setting enabling the preselected frequency range of the filter to be altered;

a conductor associated with the filter means through which frequency-setting commands are received by the filter means;

buffer means mounted on the support body for receiving and amplifying the output electrical signal of the filter means to thereby develop an output electrical signal of the buffer means;

an output conductor associated with the buffer means for enabling the output electrical signal developed by the buffer means to be conducted to the computer-based data acquisition system;

sample/hold means for receiving and freezing the output signal from the buffer means as a sample signal; and

a conductor associated with the sample/hold means through which operation of the sample/hold means is initiated.

16. The combination as defined in claim 15 wherein the device further includes means for, connected between the input means and the buffer means, enabling the output electrical signal developed by the input means to be conducted directly to the buffer means without being acted upon by the gain means, integrating means or filtering means;

the buffer means includes a switch for selectively permitting either the output electrical signal developed by the filter means or the output electrical signal developed by the input means to be conducted to the output conductor associated with the buffer means; and

an additional conductor is associated with the buffer means through which a switch-setting command signal is received by the switch of the buffer means.

17. The device as defined in claim 16 further including means for, connected between the gain means and the filter means, enabling the output electric signal developed by the gain means to be conducted directly to the filter means without being acted upon by the integrating means.

18. The device as defined in claim 15 wherein the operation of the sample/hold means is initiated by one of a low or a high voltage state of the conductor associated with the sample/hold means.