This is a project I started the other day. It uses an Arduino Uno to control two strips of RGB LEDs. The Arduino board belongs to Xiphos and he had picked it up a year or two ago for a project that didn't end up working as advertized. The Arduino has been sitting idle since. I decided to I wanted to made an LED controller to replace the one currently in use under my bench. There are two problems with the existing controller. One, it can only switch about 10 watts/channel and I cannot drive all my LEDs from a single source. And two, the PWM is 100 Hz, which is too slow and causes a noticeable strobe effect when the LEDs are the only light source. I knew the Arduino had PWM channels and I figured they should update faster than 100 Hz.
Turns out the Arduino was much easier to get up and working than I thought it would be. In no time I had a PWM dimmer test running. From my days working at DigiCon (now non-existent) I had a bunch of IFR3710
MOSFETs. These had been cut off old hardware that was going to be thrown away, and were used in an H bridge
to drive a large solenoid. They are pretty beefy devices and according to the data sheet should be able to switch around 500 watts at 12 VDC. I have around 20 and have been sitting in a bin for many years. It was time to put them to work. I wired the PWM channels to the FETs and was in no time able to control two RGB LED strips. To check for heat dissipation I connected several LED strips to a single FET and set the duty cycle to 50% (a lot of switching). It didn't change temperature at all, even pushing more then 30 watts.
When I showed the setup to Xiphos his eyes lit up. He had all kinds ideas about what could be done with the setup.