Low speed resistor and stall protection assembly for engine cooling fan motor

• US 20030206385A1
• Filed: 08/01/2002
• Published: 11/06/2003
• Est. Priority Date: 05/01/2002
• Status: Abandoned Application

• Current Assignee: Siemens VDO Automotive, Inc. (Continental AG)
• Original Assignee: Siemens VDO Automotive, Inc. (Continental AG)
• Inventors: Bere, John, Lakerdas, Andrew, Volkening, Martin
• Application Number:
  US10/210,151
• Publication Number:
  US 20030206385A1
• Time in Patent Office: Days
• US Class Current: 361/23
• CPC Class Codes: H02H 7/093 against increase beyond, or decrease below, a predetermined level of rotational speed centrifugal switches H01H35/10

Abstract

A resistor and stall protection assembly for a permanent magnet brush-type DC motor includes a first speed circuit for operating the motor at a first speed. The first speed circuit includes at least one resistor 12 for reducing voltage to the motor 14. A second speed circuit is provided for operating the motor at a speed greater than the first speed. A first connecting structure 16 is constructed and arranged to connect the assembly to a source of power 18. A second connecting structure 20 is constructed and arranged to connect the assembly to the motor 14. A sensing structure 22 is constructed and arranged to sense a motor stall condition, and a circuit protecting device 24 such as a relay or transistor is constructed and arranged to interrupt power to the motor 14 when the motor is in the stall condition.

Claims

1. A resistor and stall protection assembly for a permanent magnet brush-type DC motor, the assembly comprising:

a first speed circuit for operating the motor at a first speed, the first speed circuit including at least one resistor for reducing voltage to the motor,

a second speed circuit for operating the motor at a speed greater than the first speed,

first connecting structure constructed and arranged to connect the assembly to a source of power,

second connecting structure constructed and arranged to connect the assembly to the motor,

sensing structure constructed and arranged to sense a motor stall condition, and

a circuit protecting device constructed and arranged to interrupt power to the motor when the motor is in the stall condition.

2. The assembly according to claim 1, wherein the circuit protecting device is one of a relay and transistor and is arranged to be electrically connected to a negative side of the motor.

3. The assembly according to claim 1, wherein the circuit protecting device is one of a relay and transistor and is arranged to be electrically connected to a positive side of the motor.

4. The assembly of claim 1, wherein the first connecting structure is constructed and arranged to be connectable to a low speed terminal to provide current through the at least one resistor and a high speed terminal to provide current to the motor, bypassing the at least one resistor.

5. The assembly of claim 1, wherein the sensing structure is a current sensor.

6. The assembly of claim 1, wherein the sensing structure is a temperature sensor.

7. The assembly of claim 1, wherein the sensing structure is constructed and arranged to sense back EMF.

8. A resistor and stall protection assembly for a permanent magnet brush-type DC motor, the assembly comprising:

means for reducing voltage to the motor thereby permitting the motor to operate at a speed less than a speed of the motor when voltage to the motor is not reduced,

first means for connecting the assembly to a source of power,

second means for connecting the assembly to the motor,

means for sensing a motor stall condition, and

means for interrupting power to the motor when the motor is in the stall condition.

9. The assembly according to claim 8, wherein the means for interrupting power is one of a relay and transistor arranged to be electrically connected to a negative side of the motor.

10. The assembly according to claim 8, wherein the means for interrupting power is one of a relay and transistor arranged to be electrically connected to a positive side of the motor.

11. The assembly of claim 8, wherein the means for reducing voltage is at least one resistor.

12. The assembly according to claim 11, wherein the first means for connecting is a connector constructed and arranged to be connectable to a low speed terminal to provide current through the at least one resistor and a high speed terminal to provide current to the motor, bypassing the at least one resistor.

13. The assembly according to claim 8, wherein the means for sensing is a current sensor.

14. The assembly according to claim 8, wherein the means for sensing is a temperature sensor.

15. The assembly according to claim 8, wherein the means for sensing is constructed and arranged to sense back EMF.

16. A method of sensing stall of a permanent magnet brush-type DC motor, the method including:

providing a first speed circuit for operating the motor at a first speed,

providing a second speed circuit for operating the motor at a speed greater than the first speed,

determining if a stall condition of the motor occurs, and

when a stall condition is determined to have occurred, interrupting current to the motor.

17. The method according to claim 16, wherein the current is interrupted by one of a relay and transistor.

18. The method according to claim 16, wherein the first speed circuit includes at least one resistor.

19. The method according to claim 16, wherein the determining step detects current draw for both the first and second speed circuits.