Once I read an article on Modding.ru about the contactless power of LEDs on the cooler blades and decided to make myself the same miracle of nature. In addition, the cooler is not just luminous, but with an advanced strobe effect. I recommend. So, first we buy a large cooler 120 * 120, preferably black. Remove the impeller: to do this, remove the lock washer worn on the axle. Save the puck - it will then need to be returned to its place.
Then we wind 50 turns of wire 0.8 mm thick on the cooler, fix its ends. These outputs will be powered.
Next, we wind 50 turns of wire 0.2 mm thick on the impeller and coat with super-glue.
Now you can take on a very responsible procedure - placing LEDs on the blades. It is better to take SMD LEDs, but ordinary superbright ones will do. We distribute 7 LEDs over the blades, maintaining the impeller balance, and connect them in series. Solder the ends to the winding on the blades.
After that, we make a breaker to power this system. Scheme attached. Parts are easy to find in stores.
We connect the leads to the power and enjoy the stroboscopic effect, which can be changed with a variable resistor.