Dimming LED lighting involves a bit more than dimming traditional lighting. Using a standard dimmer is not possible in this case. Using a standard dimmer can cause the lighting to turn off, flicker, or even break completely. Therefore, it is important to carefully consider the lighting you want and the dimmer you need for it.
Dimmable LED lighting
The first thing to keep in mind is the dimmability of the LED lighting itself. You will need a dimmable LED lamp, as standard LED lighting is not dimmable. You should take this into account when searching for new lighting. If it is not explicitly stated that an LED lamp is dimmable, it is best to assume that it is NOT dimmable.
Dimming 230V LED lighting
Dimming 230V LED lighting is not possible by default; if it is, this will be explicitly stated. The (built-in) drivers of LED lighting step down the voltage from 230V to the operating voltage of 12V LEDs. Due to this voltage reduction, it is often not possible to dim the LED lighting. Should the LED lighting be dimmable, you have various options for this. These are the so-called "leading edge" or "phase cut-on" and "trailing edge" or "phase cut-off" dimmers.
230V phase cut-on dimmers (leading edge)
Phase cut-on dimmers use an inductor to dim LED lighting. This is the oldest and most affordable technique for dimming LED lighting.With leading edge dimming, a small interruption is added at the beginning of the AC voltage phase, as clearly shown in the image below. With this dimming method, hardly any energy is lost.
230V trailing edge dimmers
Trailing edge dimmers do not use a coil to dim LED lighting. In addition, the location of the interruption is also different compared to leading edge dimmers. With trailing edge dimmers, an interruption is introduced at the end of the AC voltage phase. This is clearly visible in the image below. This dimming method also results in very little energy loss. This method of dimming is newer than leading edge dimming and produces less noise. Trailing edge dimmers work best with electronic transformers.
Choosing between these two types of dimmers can be challenging. Some LED lights work better with trailing-edge dimmers, while others perform better with leading-edge dimmers. LED manufacturers often indicate which type works best.
Minimum load LED dimmer
LED dimmers may require a minimum load. Many LED dimmers only dim properly when a minimum power of 20 or 30 watts is connected. Suppose four LED lamps of 3 watts each (12 watts in total) are connected to an LED dimmer; in that case, the lamps may not dim at all or only partially.
Dimming multiple LED lights
The wattage of the LED dimmer determines the number of LED lights that can be dimmed. A common rule of thumb is that 10% of the dimmer's maximum wattage can be utilized for the number of lamps to be dimmed.
