Among the issues of LED diver is probably the latest challenges still yet to be fully solved. Dimming LEDs is theoretically easy, because analogue dimming, which is the adjustment of current, has always been an option. However, this process only works safely when combined with one LED bulb. Systems of LEDs require a more sophisticated way of dimming. Both basic types of dimming are definitely the PWM or Pulse-Width-Modulation and the analogue dimming, each of which are switched-mode regulators. Those two types are similar within the sense that they both control the time-averaged current through the diode.
Analogue dimming is a very simple way of dimming, it is the adjustment of cycle-by-cycle of the LED current regulated having a potentiometer. The current is adjusted towards the LED increasing and decreasing its intensity.
The downside of analogue dimming is that it only works safe so long as we dim one particular light bulb. Systems of Leds need a more refined technique. The difficulty of dimming a process of LED lights is that there are various types of LEDs, requiring various methods for dimming. When there is a system of lights we would like to dim, the various LEDs may react diversely to the equivalent amount of current, and because the current is reduced some LEDs can turn off later or earlier than others. Also, analogue dimming largely changes the color of the light, similarly to after it is used in combination with incandescent lights.
The most commonly used technique of LED dimmmable 12v is Pulse-Width Modulation, which is simply the cutting of the phase in a certain frequency. PWM switches the devices between fully on and fully off at a frequency that can not be told through the eye, therefore LED bulbs always run on the forward current recommended. The frequency of switching determines the brightness of light, so the longer the lighting is “on” the brighter the sunshine will be. This is actually the same technique utilized in incandescent light dimmers as well, other than incandescent lights respond to current more slowly, and therefore need a different frequency.
Two types of Pulse-With Modulation signals are used often with dimming light: the leading-edge and also the trailing edge techniques. Both of these will vary means of cutting the phase, and lead to separate dimming technologies. Probably the most frequently used dimmers of LEDs use solely the key-edge technology.
Dimmers marked as R or RL are compatible with most dimmable LEDs, since they work together with the key edge technology and do not include electronic transformers. TRIAC drivers, or devices governed by the DMX and digital addressable lighting interface (DALI) protocols and, later on, can include wireless (RF) as a control option, which is dimmers that turn or slide with a knob, all work together with dimmable LEDs. Alas leading edge technologies controlled with a touch or push button, are nzyjty powered by an electric powered transformer, excluding many dimmable LEDs.
Another type of phase-cutting strategy is trailing edge technique, usually found in MOSFET or is not suitable for the majority of dimmable LEDs. One of the latest inventions appearing on the marketplace is the RAIS lamp technology. RAIS lamps offer a higher degree of functionality and seem to work with all types of dimmers available on the market. However RAIS technology is still new, along with its long-term effect on LEDs have not been fully tested. When they turn out to be trustworthy their application both domestically and commercially, can come to be much safer and simpler than previous dimmable LED lights’.
Within the ever-evolving technologies of Leds, LED dimmable power supply are still to be developed to further compatibility and better performance. While there is no general rule for what dimmer your LED could be suitable for, always check the technical details using the distributor. Application of Leds with non-compatible dimmers might ruin the LEDs, and they are, right now, not the most affordable solution of lighting.