ADAPTIVE SHUNT FOR PULSING BRAKE LIGHT

• US 20140361687A1
• Filed: 06/10/2014
• Published: 12/11/2014
• Est. Priority Date: 06/10/2013
• Status: Active Grant

• Current Assignee: Williams & Lake LLC
• Original Assignee: Kinetech LLC
• Inventors: Olson, Mark, Utley, Todd, Seal, David
• Granted Patent: US 9,475,424 B2
• Time in Patent Office: Days
• US Class Current: 315/80
• CPC Class Codes: B60Q 1/44 for indicating braking action or preparation for braking, e.g. by detection of the foot approaching the brake pedal
• CPC Class Codes: B60Q 2900/10 Retrofit arrangements
• CPC Class Codes: F21S 43/195 Details of lamp holders, terminals or connectors

Abstract

An electronics device is configured for installation in the brake light circuitry of a vehicle braking system. The electronics device is particularly configured to provide a flashing or pulsing appearance for a brake light, such as an automobile CHMSL. The pulsing is accomplished in a precise manner and that provides additional operational safety features than standard automotive brake lights. The electronics device is configured to avoid over-triggering of the pulsating lights due to multiple application of the automobile'"'"'s brakes in a short time frame. The electronics device is further configured to function correctly even if the automobile is equipped with sophisticated computer systems that analyze the brake light circuitry, and is configured to avoid detection as a problem by the vehicle'"'"'s diagnostic systems. At the same time, the electronics device will still allow the vehicle'"'"'s diagnostic scans to detect any actual problems with the brake light system without hindrance.

Claims

1. A device configured for installation in an existing vehicle brake light circuit having a brake detection line, at least one brake light, and a return line, the device including:

a first lead, a second lead and a third lead, the first lead and the second lead both configured for connection to one of either the brake detection line or the return line of the brake light circuit, and the third lead configured for connection to either the return line or the brake detection line, the second lead and the third lead defining a device output, the device output configured for connection in parallel with the at least one brake light;

a control unit; and

a switching member connected in parallel with the output and controlled by the control unit, the switching member configured to operate in a first state or a second state, wherein current provided at the device output is reduced when the switching member operates in the second state.

2. The device of claim 1 wherein the switching member is a second switching member, the device further comprising a first switching member connected in series with the output.

3. The device of claim 2 wherein the first switching member is a first transistor and the second switching member is a second transistor.

4. The device of claim 3 wherein the first transistor is a first MOSFET and the second transistor is a second MOSFET.

5. The device of claim 2 further comprising a current sensor configured to detect a magnitude of current on the brake detection line during an initial time period following application of a vehicle brake, the control unit and the first switching member further configured to maintain the magnitude of current on the brake detection line during a second time period following the initial time period.

6. The device of claim 5 wherein the second switching member is provided in a shunt path in parallel with the device output, the control unit configured to control the second switching member such that a current through the shunt path is increased when the second switching member operates in the second state, and the current through the shunt path is reduced when the second switching member operates in the first state.

7. The device of claim 6 wherein the current sensor is a first current sensor, the device further comprising a second current sensor configured to detect a magnitude of current through the shunt path.

8. The device of claim 7 wherein the first current sensor and the second current sensor are provided by a resistive network connected between the first lead and the third lead.

9. The device of claim 1 wherein the control unit is configured to control the switching member to operate in the first state for a first time period following application of a braking voltage to the brake detection line, and to operate in the second state for a second time period following the first time period.

10. The device of claim 9 wherein the control unit is further configured to cycle between the first state and the second state for a predetermined time period following application of the braking voltage to the brake detection line.

11. A brake light control unit connected to a vehicle brake light circuit, the vehicle brake light circuit including a brake detection line, at least one brake light, and a return line, the brake light control unit including:

a first switching member connected to the brake detection line in series with the at least one brake light;

a second switching member connected to the brake detection line in parallel with the at least one brake light; and

a control unit coupled to the first switching member and the second switching member, the control unit configured to (i) detect a braking voltage on the brake detection line, (ii) control the first switching member such that a current through the first switching member is substantially constant when the braking voltage is detected on the brake detection line, and (iii) control the second switching member such that a current through the at least one brake light cycles between a first magnitude and a second magnitude that is less than the first magnitude after the braking voltage is detected on the brake detection line.

12. The brake light control unit of claim 11 wherein the second switching member is provided in a shunt path between the brake detection line and the return line.

13. The brake light control unit of claim 12 the shunt path further including at least one resistor.

14. The brake light control unit of claim 12 wherein a current through the shunt path is less when the current through the at least one brake light is the first magnitude, and the current through the shunt path is greater when the current through the at least one brake light is the second magnitude.

15. The brake light control unit of claim 11 wherein the current through the at least one brake light cycles between the first magnitude and the second magnitude for a predetermined time period after the braking voltage is detected on the brake detection line.

16. A method of controlling illumination of a brake light in a brake light circuit of a vehicle, the brake light circuit including the brake light, a brake detection line, and a return line, the method comprising:

installing a shunt path in parallel with the brake light;

applying a vehicle brake;

limiting current through the shunt path during a first time period following application of the vehicle brake; and

increasing current through the shunt path during a second time period following the first time period.

17. The method of claim 16 wherein the current through the shunt path is a first magnitude during the first time period and the current through the shunt path is a second magnitude during the second time period, the method further comprising cycling the current between the first magnitude and the second magnitude for a flashing period following application of the vehicle brake.

18. The method of claim 16 wherein the shunt path extends between the brake detection line and the return line in the brake light circuit.

19. The method of claim 16 wherein application of the vehicle brake provides a braking voltage on the brake detection line.

20. The method of claim 16 further comprising maintaining current on the brake detection line and the return line substantially constant when the braking voltage is detected on the brake detection line.