Which dimmer should be used in combination with LED lighting?

Which dimmer should be used in combination with LED lighting?
To create the ideal lighting ambiance in your home, it is practical to be able to dim LED lamps. To be able to control brightness, a special LED dimmer is required for a dimmable LED lamp or LED spot. LED dimmers are available in several versions. The range varies from ‘out of sight’ boxes that can be easily installed in panels to dimmers that feature a wireless control. And when you make the switch to LED spots, it is essential that a suitable dimmer for LED lighting be used.

LED dimmer versus conventional dimmer
LED lamps cannot be used in combination with conventional dimmers. If a LED lamp is connected to a ‘normal’ dimmer, the lamp may start to blink, buzz or vibrate. The lamp may even break down. Electronics in a LED lamp work differently from those in a halogen lamp or incandescent lamp. Dimmers have to be geared to this and special dimmers for LED lighting have the right specifications.

Dimmer options for 12-24V LED lighting
To dim 12-24V LED lamps, a LED transformer must be used to convert a 230V current into 12-24V. A LED transformer is also known as converter, LED power supply or LED driver. The transformer is installed between the 12V-24V LED lamp and the dimmer. There are three options to dim 12-24V LED lamps.

Option 1: 12-24V LED dimmer 12-24V LED dimmers should be powered by 12V or 24V DC LED transformers (not by dimmable electronic AC converters). 

Option 2: 230V ‘leading edge’ phase dimmer
 When dimming a 12-24V LED lamp using a 230V leading edge phase dimmer, make sure you read the instructions supplied with the transformer to establish if the lamps can be dimmed by means of a leading edge phase dimmer. 

Option 3: 230V ‘trailing edge’ phase dimmer A 12-24V LED lamp can be dimmed by means of a 230V trailing edge phase dimmer in combination with a dimmable electronic 12-24V LED transformer.

Dimming of a 12V-24V lamp takes place by a very rapid succession of switching the LED on and off. When the blinking frequency is lowered, the LED will start burning more weakly and it can be dimmed infinitely. Nevertheless, dimming of LED lamps remains tricky because the combination of LED dimmer and dimmable LED transformer may cause a blinking light after all. This is because, for the time being, there is no international standardisation. So make sure that you check the dimmers that are suited to your lamps on the product page.

Dimmer options for 230V LED lighting
230V LED lamps are not dimmable, unless this is specifically stated. These LED lamps feature integrated electronics that lower the 230V current to 12V (i.e. the operational voltage of LEDs). This is the reason why, in general, these lamps are not suitable for dimming. Two types of 230V dimmers can be used for 230V LED lamps or LED spots with the specification ‘dimmable’. 230V dimmers are suited to direct dimming of 230V LED lamps.

Option 1: 230V ‘leading edge’ phase dimmer 230V leading edge dimmers are the oldest and most cost-effective dimmers and they include an anti-interference spool.

Option 2: 230V ‘trailing edge’ phase dimmer 230V phase dimmers do not have an anti-interference spool (because of the integrated electronics) ensuring their low-noise operation. This is the new type of dimmer. These dimmers operate better when combined with electronic transformers, which makes them better suited to the dimming of 12-24V LED lamps.

The choice between these two types of dimmers may be difficult because some LED lamps operate better with trailing edge dimmers while others work better with leading edge dimmers. Please refer to the datasheet of the lamp to establish which dimmers work best.

Dimming more than one LED lamp
The power of the LED dimmer is decisive for the number of LED lamps to be dimmed. A common rule of thumb is that 10% of the maximal power of the dimmer can be used to dim a number of lamps. An example: a dimmer has a power of 300 Watt as a maximum. In that case, six 5 Watt LED lamps can be connected (10% of 300 Watt = 30 Watt). The number of LED lamps to be connected may differ per LED dimmer. Make sure you check this, before connecting multiple LED lamps to one single dimmer.