Method and apparatus for testing a motor

• US 6,895,809 B2
• Filed: 12/31/2002
• Issued: 05/24/2005
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: SPX Corporation
• Original Assignee: SPX Corporation
• Inventors: Raichle, Kurt
• Primary Examiner(s): McCall, Eric S.
• Assistant Examiner(s): DAVIS, OCTAVIA L
• Application Number:
  US10/331,614
• Publication Number:
  US 20040124870A1
• Time in Patent Office: 875 Days
• Field of Search: 731/19.R, 731/16, 324/772, 363/98, 318/254, 318/687, 318/727, 318/805, 318/802, 702/84, 702/183, 364/565
• US Class Current: 73/114.59
• CPC Class Codes: F02N 11/10 Safety devices F02N11/08 takes precedence
• CPC Class Codes: G01R 31/343 in operation

Abstract

A method and apparatus for testing an electric motor is provided. A voltage generator is configured to pulse a voltage into a motor. The current associated with the motor is measured and compared to the voltage pulses to determine a phase angle. The operability of the motor is determined based on the phase angle.

Claims

1. An apparatus for testing an electric motor comprising:

a voltage generator operatively connected to the motor to pulse a voltage into the motor;

a current sensor configured to sense a current associated with the motor;

a detector configured to detect a phase angle between the voltage applied to the motor and current associated with the motor;

a first differential amplifier;

a second differential amplifier; and

a signal processor configured to receive a first signal associated with the pulsed voltage from the first differential amplifier and a second signal associated with the current in the motor from the second differential amplifier,

wherein the signal processor is configured to output a signal corresponding to the phase angle and the apparatus is attached to a starter motor of an internal combustion engine.

2. The apparatus of claim 1, wherein the detector includes a display configured to display a waveform associated with the voltage pulse and a waveform associated with the current associated with the motor.

3. The apparatus of claim 1, wherein the signal processor is a digital signal processor.

4. The apparatus of claim 1, further comprising an analog to digital converter configured to convert the first and second signals from analog to digital before the first and second signals are received by the signal processor.

5. The apparatus of claim 1, wherein the signal processor is configured to control a voltage output of the voltage generator.

6. The apparatus of claim 1, wherein the voltage pulsed to the motor has a frequency greater than 60 Hz.

7. The apparatus of claim 1, wherein at least one of the voltage generator, current sensor, and detector are part of a computer configured by at least one of hardware or software to test the electric motor.

8. The apparatus of claim 7, wherein the computer is configured to access data regarding specific motors and provide diagnostic information based on the voltage and current applied to the motor.

9. An apparatus for testing an electric motor comprising:

means for generating a voltage operatively connected to the motor to pulse a voltage into the motor;

means for sensing a current configured to sense a current associated with the motor;

means for detecting configured to detect a phase angle between the voltage applied to the motor and current associated with the motor;

first means for generating a first signal associated with the pulsed voltage;

second means for generating a second signal associated with the current; and

means for signal processing configured to receive the first signal associated with the pulsed voltage from the first amplifying means and the second signal associated with the current in the motor from the second amplifying means, wherein the signal processing means is configured to send a signal corresponding to the phase angle and

the apparatus is attached to a starter motor of an internal combustion engine.

10. The apparatus of claim 9, wherein the detecting means includes means for displaying a waveform associated with the voltage pulse and configured to display a waveform associated with the current associated with the motor.

11. The apparatus of claim 9, wherein the signal processing means is a digital signal processor.

12. The apparatus of claim 9, further comprising means for converting an analog signal to a digital signal configured to convert the first and second signals from analog to digital before the first and second signals are received by the signal processing means.

13. The apparatus of claim 9, wherein the signal processing means is configured to control a voltage output of the voltage generating means.

14. The apparatus of claim 9, wherein the voltage pulsed to the motor has a frequency greater than 60 Hz.

15. The apparatus of claim 9, wherein the voltage pulsed to the motor has a frequency greater than 200 Hz.

16. A method of testing an electric motor comprising the steps of:

applying a voltage pulse to the motor wherein the motor comprises a starter motor of an internal combustion engine;

detecting a current associated with the motor;

detecting a phase angle between the voltage applied to the motor and current associated with the motor;

providing a first differential amplifier and a second differential amplifier;

configuring a signal processor to receive a first signal associated with a pulsed voltage from the first differential amplifier and a second differential amplifier;

configuring the signal processor to output a signal corresponding to the phase angle; and

comparing the phase angle between the voltage and the current.

17. The method of claim 16, further comprising comparing the phase angle between the voltage and current against known phase angles for similar electric motors and determining whether the electric motor is acceptable or not.

18. The method of claim 16, further comprising displaying at least one waveform associated with at least one of the current and voltage.

19. The method of claim 16, further comprising comparing the phase angle against known phase angels for similar electric motors, and providing diagnostic information for the electric motor.