LED Tail Lights

LEDs

The brake lights and markers lights provide separate functions, but utilize the same group of LEDs. The turn signal feature is isolated, and utilizes separate LED lamps. LED lights are contained within four rings, where the outermost is optional for the turn signal feature. The inner most ring contains eight LEDs. The second to innermost ring contains twelve LEDs. The third to innermost ring contains sixteen LEDs. All three inner rings operate in conjunction with the brake light and marker light functions. The outermost ring may contain 24 LEDs, either orange or red. This LED group operates in conjunction with the turn signal function, separate from the three inner rings. LED emitter arrangement is linear, and spans from end to end. All LEDs operate in conjunction with the brake light and marker functions.

LED Brake Lights

LED tail lights marker and brake light components utilize domed lens LED lights featuring a 25-degree viewing angle. This provides optical characteristics that promote maximum visibility from behind the vehicle. Typical dominate wavelength is 631 nm (deep red). The following specifications pertain to LED brake lights only. To perform approximate calculations for marker mode, you must divide the following values by two. Total typical luminous intensity is 30,600 mcd. The total photometric output, measured in lumens, is 6.43. Total radiometric output, measured in watts, is 0.0368.

LED Turn Signals

Optional turn signal feature available on circular models, utilizes flat lens LED emitters featuring a 120-degree viewing angle. This provides optical characteristics that promote maximum visibility at shorter distances, from left and right sides near the rear of the vehicle. Typical dominate wavelength is 605 nm (orange). Total typical luminous intensity is 2,400 mcd. The total photometric output, measured in lumens, is 7.54. Total radiometric output, measured in watts, is 0.01947. Turn signal feature is also available in a standard red LED light configuration. This special configuration will incorporate LEDs identical to the standard marker light / LED brake lights.

Tail Light LED Circuit Configurations

Marker and brake light components consist of nine series circuits, each containing four LED lights. Turn signal components optional on circular models consist of six series circuits, each containing four light emitting diodes. A network of parallel resistors offers dual intensity modes. Appling power to the marker terminal results in all LED lights operating at approximately 50%. Applying power simultaneously to marker and brake terminals results in all LED emitters operating at 100%. To promote proper turn signal function, some vehicles may require an external load resistor (not included). A rectifier diode located in proximity to each power terminal prevents a reverse polarity scenario within the vehicle wiring.

Tail Light Circuit Boards

Circular taillight models consist of a five-layer printed circuit board, including solder-masked top and bottom layers. Linear LED tail lights consist of a two-layer printed circuit board with solder mask on both layers. Electronic component placement is restricted to the top board layer. These surface mount components do not feature through-pins, which pass through to the bottom board layer. The result is a smooth rear surface, which promotes a flush mounting configuration.

Circuit Board Dimensions

Circular LED tail lights measure 2.5 inches in diameter. Linear tail light models measure 10.5 inches in length and 0.5 inch in width. Overall board thickness is 0.062 inch excluding all electronics. The following height dimensions account for circuit board thickness. Maximum height to the top of the rectifier diodes is approximately 0.17 inch. Height to the top of marker light / LED brake lights is approximately 0.162 inch. On circular models, height to the top of the turn signal LED lights is approximately 0.144 inch. All wire terminals measure 0.067 inch in diameter. Individual component dimensions are located on manufacture's datasheets corresponding with each specific component. Refer to the subsequent section containing the component datasheets for more information.

Circuit Board Components

The taillight consists entirely of SMT optoelectronics and other surface mounted components. One benefit of SMT includes the ability to increase component density and fit a greater total number of light emitting diodes onto the LED tail lights. SMT optoelectronics also feature a minimal height dimension, allowing the LED tail lights to remain extremely thin. Other advantages of surface mount technology include ease of assembly, high cost efficiently, and a lower thermal resistance from junction to ambient. The following links contain additional information regarding individual electronic components incorporated into LED brake lights. Note that actual components may be equivalents. All file formats are PDF.

• Marker Light and Brake Light LEDs (.pdf)
• Turn signal LEDs (.pdf)
• Rectifier Diodes (.pdf)
• Marker Light Resistors (.pdf)