LED Lighting with a Dimmer

To adjust the lighting to match the atmosphere of a room, it's often a good idea to invest in a dimmer. This allows you to make the lighting brighter when you need more visibility, and dim it when the room requires a cosy, ambient setting. With a dimmer, you can create different moods within the same space.

What is a Dimmer?

A dimmer is a type of switch that allows you to regulate the power supply or voltage to an electrical device. The most common dimmer is a light dimmer, which lets you adjust the brightness of your lamps. A dimmer has a minimum and maximum power capacity. If you try to dim a lamp that has a lower power than the minimum rating, the lamp may flicker. If you try to dim a lamp with a higher power than the maximum rating of the dimmer, it is likely that the dimmer will break. Always check these limits when installing a dimmer.

What Type of Dimmer Do I Need for LED Lighting?

There are generally two types of dimmers: dimmers that use phase-cutting, and dimmers that use phase-cut-off. Phase-cutting means that at the beginning of each cycle (or phase), the alternating current is briefly interrupted. Below is a diagram of how phase-cutting works.

In addition, there are dimmers that use phase-cut-off. Phase-cut-off means that the alternating current is briefly interrupted at the end of each cycle/phase. Dimmers with phase-cut-off are almost always used for dimmableLED lamps. Below is a schematic representation of how phase-cut-off works.

Today, there are also universal dimmers that support both phase-cutting and phase-cut-off. This ensures that your lamp will work with this dimmer! When installing a dimmer, be sure that the LED lamps or spots you purchase are also dimmable. It’s not recommended to connect a dimmer to a non-dimmable LED lamp.

How Many LED Spots Can Be Connected to a Dimmer?

The number of LED spots that can be connected to a dimmer depends on the dimmer’s minimum and maximum power ratings, as well as the power rating of the LED spots. A dimmer that only needs to dim 6 LED spots will have a different power rating than one that needs to dim 16 LED spots. As a rule of thumb, the total power of the connected lamps should be about 10% lower than the maximum capacity of the dimmer. For example, if you have a dimmer rated at 2-100 watts, and LED spots that consume 4W each, it’s advisable to set the maximum power to 90W on the dimmer. Therefore, 90/4 = 22 to 23 LED lamps of 4W can be connected to this dimmer.