Risun offers active thermal solutions for LED lighting

Originally the world-leading micro-fan supplier for the cooling of pico projectors, mobile internet devices (MIDs), and ultra-thin computers, Risun Expanse Corp. has made strong moves into a new horizon, the active thermal solutions for LED lighting.

By adding two round-framed axial cooling fans, RRA3008 (Φ30×8mm) and RRA6016 (Φ60×16mm) to the product lineup, Risun is turning a new page on the cooling of high power LEDs.

In response to the eco-friendly appeal for energy-saving and low carbon emission, LED has long been regarded as the viable alternative to inefficient incandescent lamps and eco-unfriendly compact fluorescent lamps. However, on the way to become a truly general lighting solution, there are several issues left to be tackled for LED. One major issue of LED is the luminous decay caused by high power and temperature from the ever-increasing demand for high brightness output. The elevated temperature will pose a serious problem to the service life of LEDs.

For the capability of pure passive cooling means, such as heat sink, to keep up with the heat-generation rate of high power LEDs, the size and weight of heat sink will usually go up to an unreasonable level, making it impractical for the cooling of high brightness LEDs and setting the stage for the active cooling fans with much higher cooling efficiency.

Rated at 5V and about 0.35W, both RRA3008 and RRA6016 adopt a stator structure with an axial air-gap and without iron cores or silicon steel stacks, which is unprecedented among LED cooling fans usually consisting of a stator structure with a radial air-gap and silicon steel stacks, the causes of induced eddy current losses, higher fan power, and poor fan efficiency. Without silicon steels, the diameter of fan impeller can be smaller and the length of fan blades longer, meaning a cooling fan can achieve the same performance at a lower rotation speed and therefore lower noise level compared to its counterpart with silicon steels.