Amongst the issues of led power supply 12v is probably the latest challenges still yet to be fully solved. Dimming Light emitting diodes is theoretically easy, because analogue dimming, which is the adjustment of current, has long been an option. However, this process only works safely when used with one LED bulb. Systems of LEDs demand a more sophisticated way of dimming. The 2 basic types of dimming are the PWM or Pulse-Width-Modulation and also the analogue dimming, both of which are switched-mode regulators. These two types are similar within the sense that they both control the time-averaged current through the diode.
Analogue dimming is definitely a simple way of dimming, this is the adjustment of cycle-by-cycle in the LED current regulated using a potentiometer. The existing is adjusted to the LED increasing and decreasing its intensity.
The drawback to analogue dimming is that it only works safe provided that we dim one particular light bulb. Systems of LED lights need a more refined technique. The difficulty of dimming a system of LED lights is that there are various kinds of LEDs, requiring various methods for dimming. If you have a system of lights we wish to dim, the many LEDs may react diversely to the same amount of current, and because the current is reduced some LEDs can turn off later or sooner than others. Also, analogue dimming largely changes the color from the light, similarly to when it is used in combination with incandescent lights.
Probably the most commonly used manner of dimming LEDs is Pulse-Width Modulation, which can be basically the cutting of the phase with a certain frequency. PWM switches the devices between fully on and fully off with a frequency that can not be told through the human 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 lighting is going to be. This is the same technique used in incandescent light dimmers also, except that incandescent lights react to current slower, and therefore need a different frequency.
Two kinds of Pulse-With Modulation signals are utilized often with dimming light: the key-edge and the trailing edge techniques. Those two will vary means of cutting the phase, and lead to separate dimming technologies. Probably the most frequently used dimmers of LEDs use solely the top-edge technology. Dimmers marked as R or RL are compatible with most 12 volt dimmable led lights, given that they work 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, in the future, may include wireless (RF) as a control option, that is certainly dimmers that turn or slide having a knob, all assist dimmable LEDs.
Alas leading edge technologies controlled using a touch or push button, are frequently powered by an electrical transformer, excluding many dimmable LEDs.
One other type of phase-cutting technique is trailing edge technique, usually used in MOSFET or perhaps is not suitable for almost all dimmable LEDs. One of many latest inventions appearing on the market is the RAIS lamp technology. RAIS lamps give you a higher level of functionality and seem to work with all sorts of dimmers available on the market. However RAIS technology is qtjzkb new, and 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 grow to be much safer and simpler than previous dimmable LED lights’.
Inside the ever-evolving technologies of Leds, led driver 12v remain to be developed to further compatibility and better performance. While there is no general rule for which dimmer your LED could be ideal for, check the technical details using the distributor. Use of Leds with non-compatible dimmers might ruin the LEDs, plus they are, currently, not the cheapest solution of lighting.