Alternator testing device and method

• US 6,791,332 B2
• Filed: 12/10/2002
• Issued: 09/14/2004
• Est. Priority Date: 12/10/2002
• Status: Active Grant

• Current Assignee: SPX Corporation
• Original Assignee: SPX Corporation
• Inventors: Raichle, Kurt
• Primary Examiner(s): Lo, N.
• Assistant Examiner(s): He, Amy
• Application Number:
  US10/314,971
• Publication Number:
  US 20040108855A1
• Time in Patent Office: 644 Days
• Field of Search: 324/426, 324/772, 324/429, 318/490
• US Class Current: 324/429
• CPC Class Codes: G01R 31/34 Testing dynamo-electric machines

Abstract

An alternator testing system is disclosed that includes a current source, a motor, and a drive belt. The drive belt couples the motor to an alternator, which operates outside of a motor vehicle, and the current source and the motor enable diodes of the alternator to output a current that is not limited by input power to the motor. Accordingly, defective diodes may be detected.

Claims

1. An alternator testing system, comprising:

a motor that drives an alternator undergoing testing, the motor comprises an initial current source for the alternator;

a secondary current source that provides additional current to the alternator in order to simulate approximate full capacity capabilities;

a drive belt, coupled to the alternator and the motor;

a simulated load that is detachably placed on an output voltage of the alternator;

a current sensor linked to the secondary current source and load, the current sensor monitors and reports current from the current source and the simulated load; and

an evaluator that receives the reports from the current sensor and ascertains a presence of a ripple current.

2. The alternator testing system of claim 1, wherein the current source is a switching power supply.

3. The alternator testing system of claim 1, wherein the current source is a transformer.

4. The alternator testing system of claim 1, wherein the current source delivers approximately eighty amperes (amps) of current to the alternator.

5. The alternator testing system of claim 4, wherein the input power to the motor is a 120 volt alternating current (AC) power source.

6. The alternator system of claim 5, wherein the motor causes the alternator to output between approximately five to fifteen amps.

7. The alternator testing system of claim 6, wherein the motor and the current source cause the alternator to output between 85 to 100 amps.

8. The alternator testing system of claim 1, further comprising a resistor positioned between a first output terminal of the alternator and the current source.

9. The alternator testing system of claim 8, wherein the resistor is utilized to establish an excitation voltage for the alternator.

10. The alternator testing system of claim 1, further comprising a resistor, wherein the current through the resistor is measured.

11. The resistor of claim 10, wherein the resistor is positioned between the first output terminal of the alternator and ground.

12. The alternator testing system of claim 1, further comprising an analog-to-digital (A/D) converter that converts the output voltage to a first digital signal.

13. The alternator testing system of claim 12, wherein an output voltage from the alternator is fed into the A/D converter and a second digital signal is generated.

14. The alternator testing system of claim 13, a wherein the evaluator is coupled to the A/D converter, the evaluator has software that analyzes the second digital signal and identifies irregularities in performance by diodes in the alternator.

15. The alternator testing system of claim 12, wherein the evaluator has software that analyzes the current and identifies irregularities in performance by diodes in the alternator.

16. An alternator testing system, comprising:

means for driving an alternator;

means for supplying a current to an alternator that is independent from the means for driving such that the alternator is tested under approximate full capacity working capabilities;

means for coupling the driving means to the alternator;

means for simulating a load on an output voltage on the alternator;

means for sensing a current reading on the means for supplying and the means for simulating, the means for sensing monitors and reports this current; and

means for evaluating the presence of a ripple current from the current reading.

17. The alternator testing system of claim 16, wherein the driving means is a motor.

18. The alternator testing system of claim 16, wherein the current supplying means is an independent current source.

19. A method for testing an alternator, comprising:

utilizing an independent current source to supply a first current to an alternator;

generating a second current from the alternator utilizing a motor, wherein the first current and the second current enable diodes of the alternator to output a current that is not limited by input power to the motor;

simulating a load on the alternator;

sensing the first and second current with a current sensor; and

evaluating the presence of a ripple current from the sensed first and second current.

20. The method for testing an alternator of claim 19, further comprising converting a voltage output from the current sensor to a digital signal.

21. The method for testing an alternator of claim 20, further comprising analyzing the digital signal for occurrences of ripple current.