Apparatus and method for comparing output signals indicative of engine rotational speed and/or generator rotational speed

• US 20030057925A1
• Filed: 09/24/2001
• Published: 03/27/2003
• Est. Priority Date: 09/24/2001
• Status: Active Grant

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Harmon, Jack Douglas
• Granted Patent: US 6,750,635 B2
• Time in Patent Office: Days
• US Class Current: 322/29
• CPC Class Codes: H02J 7/1446 in response to parameters of a vehicle
• CPC Class Codes: H02J 7/2434 with pulse modulation
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

An apparatus and method are provided to deliver a pair of output signals indicative of engine rotational speed and/or generator rotational speed. The signals are compared to each in order to determine if a generator is operating properly. At least one output signal is delivered to, or developed internally and used by, a voltage regulator of the generator. One output signal is generated based on a ripple on a positive voltage input to the voltage regulator from a generator. The other signal is indicative of the voltage at the rectifier bridge.

Claims

1. An apparatus adapted to compare a pair of speed-indicative signals indicative of engine rotational speed or indicative of generator rotational speed, comprising:

an input port for electrical connection to a positive voltage output from a rectifier of a generator;

speed signal circuitry connected to the input port and adapted to convert rippling in said positive voltage output into a speed-indicative signal indicative of engine rotational speed or indicative of generator rotational speed;

an output port connected to said circuitry and adapted to apply said speed-indicative signal to a comparator; and

a means for providing a voltage signal indicative of a voltage across a rectifier bridge of an alternator, said voltage signal being received by said comparator.

2. The apparatus as in claim 1, wherein said comparator provides a comparator output indicating any differential between said voltage signal and said speed-indicative signal.

3. The apparatus as in claim 2, wherein said comparator output is inputted into a voltage regulation unit, said voltage regulation unit modifying the output of said alternator in response to the value of said comparator output.

4. The apparatus as in claim 3, wherein an indicator light is activated when said comparator output indicates a differential between said voltage signal and said speed-indicative signal.

5. The apparatus as in claim 2, wherein said speed signal circuitry is adapted to apply said speed-indicative signal with a frequency of about one sixth a frequency of the rippling.

6. The apparatus as in claim 2, wherein said speed signal circuitry is adapted to apply said speed-indicative signal as a pulse train with a frequency of about one sixth a frequency of the rippling.

7. The apparatus as in claim 2, wherein said speed signal circuitry includes a band pass filter that passes a range of frequencies in which a frequency of said rippling substantially remains when an associated engine operates at rotational speeds of interest.

8. The apparatus as in claim 7, wherein said range of frequencies is between about 80 and about 1,500 Hertz.

9. The apparatus as in claim 7, wherein said range of frequencies includes typical frequencies exhibited by the rippling when the engine is idling or otherwise operating at a rotational speed to be treated substantially the same as idling by a voltage regulator.

10. The apparatus as in claim 2, wherein said speed signal circuitry includes a phase locked loop.

11. The apparatus as in claim 2, wherein said speed signal circuitry includes an amplifier adapted to amplify an AC component of said rippling.

12. The apparatus as in claim 2, wherein said speed signal circuitry includes:

an amplifier adapted to amplify an AC component of said rippling;

a band pass filter adapted to pass a range of frequencies in which a frequency of said rippling substantially remains during operation of an associated engine at rotational speeds of interest;

a frequency divider adapted to divide frequencies passed by said band pass filter by a factor of about six to provide a frequency divided signal; and

a phase locked loop connected to said frequency divider and adapted to minimize effects of electrical noise on said frequency divided signal, said phase locked loop being arranged so that said frequency divided signal is applied as said speed-indicative signal.

13. A method for providing a signal indicative of an alternator operation, comprising:

determining a first speed-indicative signal indicative of engine rotational speed or indicative of generator rotational speed by detecting rippling in a positive voltage output from a rectifier of a generator, converting said rippling in said positive voltage output into a speed-indicative signal indicative of engine rotational speed or indicative of generator rotational speed;

comparing said first speed-indicative signal to a voltage signal across said rectifier; and

providing a comparative output signal corresponding to the difference between said first speed-indicative signal and said voltage signal.

14. The method as in claim 13, further comprising the step of applying said speed-indicative signal and said voltage signal to control inputs of a voltage regulator.

15. The method as in claim 14, wherein said voltage regulator modifies the operation of said alternator in response to said comparator output signal.

16. The method as in claim 14, wherein said voltage regulator includes a means for providing said comparator output.

17. The method as in claim 14, wherein said comparator output signal is used to provide a signal to an indicator light, said indicator light indicating that the operation of said alternator is outside a preferred operational range.

18. The method as in claim 13, wherein said step of converting said rippling is performed so that the speed-indicative signal has a frequency of about one sixth a frequency of the rippling.

19. The method as in claim 13, wherein said step of converting said rippling is performed so that said speed-indicative signal is a pulse train with a frequency of about one sixth a frequency of the rippling.

20. The method as in claim 13, further comprising the step of filtering said rippling to pass a range of frequencies in which a frequency of said rippling substantially remains when an associated engine operates at rotational speeds of interest.

21. The method as in claim 20, wherein said range of frequencies is between about 80 and about 1,500 Hertz.

22. The method as in claim 20, wherein said range of frequencies includes typical frequencies exhibited by the rippling when the engine is idling or otherwise operating at a rotational speed to be treated substantially the same as idling by a voltage regulator.

23. The method as in claim 13, further comprising the step of minimizing effects of noise on said speed-indicative signal, using a phase locked loop.

24. The method as in claim 13, wherein said step of converting the rippling includes the step of amplifying an AC component of said rippling.

25. The method as in claim 13, wherein said step of converting the ripping includes the steps of:

amplifying an AC component of said rippling;

filtering said rippling to pass a range of frequencies in which a frequency of said rippling substantially remains during operation of an associated engine at rotational speeds of interest;

frequency dividing frequencies passed by said band pass filter by a factor of about six to provide a frequency divided signal; and

minimizing effects of electrical noise on said frequency divided signal using a phase locked loop.