Key Characteristics

1. Reliability and service life

The expected life of the LED is 50,000 hours, while the tungsten halogen lamp is 20,000 hours and the tungsten incandescent lamp is 3,000 hours. Compared with incandescent lamps, LEDs are structurally strong and are not susceptible to vibration. The brightness of the light output during use is not significantly reduced. Lighting solutions based on multiple LEDs also have the "redundancy" benefit, and even if one LED fails, the lighting can continue to be used.

Proper use of LEDs (especially the temperature of the LEDs properly controlled) can effectively extend the life expectancy of the LEDs. Conversely, if the temperature is too high, the LED is easily damaged. LED applications also involve many legal definition issues in automotive lighting. Most countries have a clear definition of brake lights or headlights - lights on or off. However, for lamps with multiple LEDs, it is difficult to accurately define whether the lamps have been damaged. Manufacturers and legislatures are defining ways to use LEDs.

2. Efficiency / lumens per watt

Compared to standard incandescent lamps, LEDs consume more light output per unit of electrical energy. However, the advantages of the actual light output of the LED are not significant when compared to halogen lamps. The latest LEDs have excellent lumens per watt, but some values are obtained under optimized conditions and are usually not obtained under the highest output conditions. In general, when the current of the LED increases, the amount of light output does not increase linearly. Therefore, even if the LED outputs x lumens at a current of 0.5 A, it does not output 2 x lumens at 1.0 A current.

3. Response speed

Taking the brake light and the direction indicator tube as an example, assuming that the vehicle has a speed of 125 km/h, that is, 35 m/s, the hot start time of the incandescent lamp is about 250 msec, and the fast-reacting LED can be sent about 8 m earlier. Brake warnings to effectively avoid car collisions. The same is true for the indicator light.

4. Directionality

Another key feature is the way LEDs are illuminated. Unlike incandescent lamps, LEDs emit light only through one surface, which is good for headlamps and aeronautical light applications, but may not be suitable for other lighting applications.