There are two types of PWM used frequently with dimming lights. These, determining the place of cutting the phase are called the leading-edge and the trailing-edge techniques. Traditional dimmers usually use the leading edge technique more frequently, although trailing-edge technique is used too. For dimmable LED lights it is the leading-edge technology which works. Dimmers marked as R or RL are suitable for most dimmable LED lights, like TRIAC drivers, or devices governed by the DMX and digital addressable lighting interface (DALI) protocols. These dimmers are controlled with a turn or slide with a knob. Dimmers controlled with a touch or push button are usually controlled with electric transformers, therefore they cannot be used for dimming LEDs.

Trailing-edge dimmers, like the MOSFET are not suitable for the mass of the dimmable LEDs. The solution of dimming with these drivers was recently solved by the so-called RAIS technique, however the reliability of these products have not been fully tested. RAIS lamps offer a higher degree of functionality and seem to work with all types of dimmers available on the market, so on the long run their application is easier for customers.

In the ever-evolving technologies of LED lights , dimmable LED lights are still to be developed to further compatibility and better performance. Since there is no general rule for what dimmer your LED might be suitable for, always check the technical details with the distributor. Application of LED lights with non-compatible dimmers might ruin the LEDs, and they are, at the moment, not the cheapest solution of lighting.