TUNABLE STARTER RESISTOR

• US 20150308395A1
• Filed: 04/29/2014
• Published: 10/29/2015
• Est. Priority Date: 04/29/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: ATLURU, Ravi, LIU, Xiangying, LE, Christina, HAMPTON, Kenneth W., DE BIASI, Charles
• Granted Patent: US 9,745,941 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02N 11/00 Starting of engines by means of electric motors
• CPC Class Codes: F02N 11/08 Circuits or control means specially adapted for starting of engines
• CPC Class Codes: F02N 11/087 Details of the switching means in starting circuits, e.g. relays or electronic switches
• CPC Class Codes: F02N 11/10 Safety devices F02N11/08 takes precedence
• CPC Class Codes: F02N 15/067 the starter comprising an electro-magnetically actuated lever
• CPC Class Codes: F02N 2011/0881 Components of the circuit not provided for by previous groups
• CPC Class Codes: H01C 10/10 adjustable by mechanical pressure or force
• CPC Class Codes: H01C 17/0652 containing carbon or carbides
• CPC Class Codes: H01C 17/06526 composed of metals
• CPC Class Codes: H01C 17/30 adapted for baking
• CPC Class Codes: H01C 7/06 including means to minimise changes in resistance with changes in temperature

Abstract

A passive two-terminal circuit element may include a resistor including a carbon-metal composite resistive element. The resistive element is configured to maintain a resistivity that fluctuates less than one tenth of an ohm per ten degree temperature change up to 400 degrees Celsius.

Claims

1. A passive two-terminal circuit element comprising:

a resistor including a carbon-metal composite resistive element configured to maintain a resistivity that fluctuates less than one tenth of an ohm per ten degree temperature change up to 400 degrees Celsius.

2. The resistor of claim 1, wherein the resistive element is approximately 75-85% carbon.

3. The resistor of claim 1, wherein the resistive element comprises carbon and copper particles, the carbon particles extending along an axis parallel with a current flow through the resistive element.

4. The resistor of claim 3, wherein the copper particles extend perpendicular to the carbon.

5. The resistor of claim 1, wherein the resistive element is further configured to maintain a resistivity that fluctuates less than one hundredth of an ohm per ten degree temperature change up to 400 degrees Celsius.

6. A starter circuit for a vehicle comprising:

a battery;

a starter motor;

a solenoid switch electrically connected between the battery and the starter motor, the switch configured to close in response to an ignition signal; and

a resistor including a carbon-metal composite resistive element arranged between the battery and the starter motor and configured to act on a current drawn from the battery in response to the solenoid switch closing.

7. The circuit of claim 6, wherein the resistive element is composed of carbon and copper.

8. The circuit of claim 6, wherein the resistor includes wire.

9. The circuit of claim 6, wherein the resistor has a length of approximately 0.5 inches and a diameter of approximately 0.25 inches.

10. The circuit of claim 6, wherein the resistive element is approximately 75-85% carbon.

11. The circuit of claim 6, wherein the resistor is arranged between the solenoid switch and the motor.

12. The circuit of claim 6, wherein the resistor is arranged between the battery and the solenoid switch.

13. The circuit of claim 6, where in the resistor is internal to the starter motor.

14. A starter circuit for a vehicle comprising:

a battery;

a starter motor; and

a resistor including a carbon-metal composite resistive element arranged between the battery and the starter motor and configured to act on a current drawn from the battery in response to a solenoid switch closing.

15. The circuit of claim 14, wherein the resistive element is configured to maintain a resistivity for up to 400 degrees Celsius.

16. The circuit of claim 15, wherein the resistivity of the resistive element fluctuates no more than one hundredth of an ohm over a ten degree temperature change.

17. The circuit of claim 14, wherein the resistive element is approximately 75-85% carbon.

18. The circuit of claim 14, wherein the resistive element comprises carbon and copper particles, the carbon particles extending along an axis parallel with a current flow through the resistive element.

19. The circuit of claim 18, wherein the copper particles extend perpendicular to the carbon.

20. The circuit of claim 18, wherein the carbon and copper particles are sintered together.