Choosing the right LED dimmer
One of the frequently asked questions about LED lighting is whether or not LED lamps and LED spotlights are dimmable. LED lamps and LED spotlights are indeed dimmable, but the process of making them dimmable requires some explanation. Below you will find a step-by-step guide to making your LED lighting dimmable using an LED dimmer.
LED dimmer vs conventional dimmer
LED lamps cannot be used in combination with a conventional dimmer. Connecting an LED lamps to a ‘regular’ dimmer may cause the lamp to flicker, hum or vibrate. The lamp may even blow. The electronics in a LED lamp function differently from those in a halogen or filament lamp, and as the dimmer needs to be compatible, a LED dimmer is used for LED lamps.
Dimming LEDs with a LED dimmer
Dimmable LED lamps allow you to create the perfect ambiance at home. In order to determine the brightness of a dimmable LED lamp or a dimmable LED spotlight, a special LED dimmer is required. These LED dimmers come in various designs, varying from concealable boxes that can easily be installed behind a panel to ones with wireless control.
Dimming 12-24V LEDs
For dimming 12-24V LED lamps, an LED transformer that converts 230V to 12-24V voltage is required. An LED transformer is often called a ‘trafo’, a LED driver or LED power supply. The transformer is installed between the 12-24V lamp and the dimmer. There are 3 options for dimming 12-24V LED lamps.
Option 1: 12-24V LED dimmer
12-24V LED dimmers must be powered by a 12V or 24V DC LED transformer (so not by a dimmable electronic AC transformer).
Option 2: 230V ‘leading edge’ phase-angle dimmer
For more information on dimming 12-24V LED lamps using a 230V phase-angle dimmer, consult the transformer user manual in order to determine whether the lamps can be dimmed using a phase-angle dimmer.
Option 3: 230V ‘trailing edge’ phase-cut dimmer
A 12-24V LED lamp can be dimmed using a 230V phase-cut dimmer in combination with a dimmable, electronic 12-24V LED transformer.
12V-24V is dimmed when the LED is switched on and off very quickly. Reducing the flicker frequency causes the LED to burn more weakly, which allows you to dim the LED continuously. Nevertheless, dimming LEDs remains difficult as the combination of the LED dimmer / dimmable LED transformer and the electronics in the LED lamps / LED spotlights may still cause the light to flicker. This is because European and Chinese manufacturers do not yet have an international standard.
Dimming 230V LEDs
2230V LED lamps are not dimmable unless specifically indicated. 230V LED lamps have built-in electronics that reduce the 230V charge to 12V (the working voltage for LED). For that reason, these lamps are usually unsuitable for dimming. For the 230V LED lamps or LED spotlights that are indicated as dimmable, two types of 230V dimmers can be used. These 230V dimmers are suitable for directly dimming 230V LED lamps.
Option 1: 230V ‘leading edge’ phase-angle dimmer
230V phase-angle dimmers are the oldest and cheapest dimmers and use a suppression coil.
Option 2: 230V ‘trailing edge’ phase-cut dimmer
230V phase-cut dimmers are low-noise because they do not have a suppression coil (because of the built-in electronics). This is the new (more expensive) type of dimmer. These dimmers function better in combination with electronic transformers and are therefore more suitable for dimming 12-24V LED lamps.
Choosing between the two types of dimmers can be troublesome as some LED lamps function better with phase-cut dimmers while others tend to function better with a phase-angle dimmer. LED lamp manufacturers often indicate which type is most suitable.
LED dimmer minimum load
LED dimmers may require a minimum load. Many LED dimmers only dim when connected to a minimum electric potential of 20 or 30 watts. Suppose that four LED lamps of 3 watts each (12 watts in total) are connected to an LED dimmer. It could then be the case that the lamps do not or only partly dim.
Dimming multiple LED lamps
The potential of the LED dimmer determines the number of LED lamps that can be dimmed. A well-used rule of thumb is that 10% of the maximum potential of the dimmer can be used for the lamps that need to be dimmed.
Example: a certain dimmer has a maximum potential of 300 watts. In this case, a maximum of 6 lamps of 5 watts each can be connected (10% of 300 watts = 30 watts).
The number of LED lamps that can be connected may differ per LED dimmer. Should you wish to connect a large number of lamps to a single dimmer, please test this in prior to installment.
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