Cool White LED Module

The Challenge

A global appliance manufacturer was looking to transition away from incandescent bulbs to illuminate the cavity for their ice and water dispenser. The goal was to have higher intensity, better light distribution and energy savings. They came to Lumex with the idea that they could use a 1 watt high power white LED in order to achieve this goal. They also needed a “cool white” color temperature with a very specific light distribution within the cavity. They needed the light to hit the activation paddles, the water dispenser and the ice dispenser, preferably all with the same light intensity and color. The illumination module also had to be easily field replaceable.

The Solution

The Lumex Technical Design Team reviewed the options and quickly concluded that using the high power LED would create additional challenges including heat management, shorter life hours and uneven light distribution in the cavity. As an alternative, we proposed using 3 white 5mm LEDs in a small molded module with an integrated PCB and quick disconnect 2-pin connector at the end of a wire assembly. The LEDs would all be color and intensity matched so that every LED within the module and every module would have the same 2700° Kelvin cold color temperature. This solution would also allow light to be pointed from each of the three LEDs into the exact location in the cavity where light was needed, rather than relying on over-saturating the entire cavity with light.

The Value Proposition

The appliance manufacturer ended up going with the Lumex proposed modular solution, which exceeded their goals. Lumex was able to reduce the customer’s service costs by replacing an incandescent bulb with an LED solution which would last more than 10 years without replacement. The module used less power by driving 3 LEDs at 18mA vs 1 high power at 1 watt which increased the energy rating of the refrigerator. Finally, the custom configuration achieved light distribution exactly where the customer wanted it. In addition, Lumex was able to achieve 0 ppm failures over a five year period, further saving the customer time and cost on potential field failures and returns from the consumer.