Tunable starter resistor

Patent metadata

Field	Value
Publication number	US-9745941-B2
Application number	US-201414264625-A
Country	US
Kind code	B2
Filing date	Apr 29, 2014
Priority date	Apr 29, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

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.

First claim

What is claimed is:

1. 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, the resistor comprising carbon particles and copper particles, the carbon particles extending along an axis parallel with the current through the resistor and the copper particles extending perpendicular to the carbon particles.

2. The circuit of claim 1 , wherein the resistor includes wire.

3. The circuit of claim 1 , wherein the resistor has a length of approximately 0.5 inches and a diameter of approximately 0.25 inches.

4. The circuit of claim 1 , wherein the resistor is approximately 75-85% carbon.

5. The circuit of claim 1 , wherein the resistor is arranged between the solenoid switch and the motor.

6. The circuit of claim 1 , wherein the resistor is arranged between the battery and the solenoid switch.

7. The circuit of claim 1 , wherein the resistor is internal to the starter motor.

8. 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, wherein the resistor comprises carbon particles extending perpendicular to copper particles, the carbon particles extending along an axis parallel with a current flow through the resistor.

9. The circuit of claim 8 , wherein the resistor is configured to maintain a resistivity for up to 400 degrees Celsius.

10. The circuit of claim 9 , wherein the resistivity of the resistor fluctuates no more than one hundredth of an ohm over a ten degree temperature change.

11. The circuit of claim 8 , wherein the resistor is approximately 75-85% carbon.

12. The circuit of claim 8 , wherein the carbon and copper particles are sintered together.

Assignees

• Ford Global Tech Llc

Inventors

• Atluru Ravi
• Liu Xiangying
• Le Christina
• Hampton Kenneth W
• De Biasi Charles

Classifications

• F02N11/10

  Safety devices (F02N11/08 takes precedence) · CPC title

• F02N11/087

  Details of the switching means in starting circuits, e.g. relays or electronic switches · CPC title

• H01C17/0652

  containing carbon or carbides · CPC title

• F02N2011/0881

  Components of the circuit not provided for by previous groups · CPC title

• F02N15/067

  the starter comprising an electro-magnetically actuated lever · CPC title