Crownstones can operate as a dimmer for a large set of lamps. A Crownstone can dim a lamp up to 100 Watt and can only dim individual lamps.

The type of lamps that can be dimmed:

  • Incandescent light bulbs.
  • Halogen lamps.
  • LEDs.

The type of lamps that cannot be dimmed:

  • Fluorescent lights.

Please, do not try dim anything that is not a light!


Note that if your lamp comes with an dapter, this adapter needs to be placed between the Crownstone and the lights. It totally depends on the adapter if it on itself can be dimmed. If it is a straightforward transformer, this very likely is the case.

Carbon Filament Bulbs

There are light bulbs in the market that are advertised as carbon filament bulbs (Dutch: kooldraad). Often they don’t contain carbon at all. Bulbs with carbon filament created from bamboo were the bulbs patented by Edison (history) long before tungsten became widespread. One of the challenges was to turn the carbon into graphite. Graphite has a positive rather than a negative temperature coefficient. The latter is detrimental to the lifetime of a lamp: the warmer it gets, the lower the resistance, the more current it draws, the warmer it gets. You don’t want that as a bulb designer! Apparently, nowadays you can buy these beautiful big light bulbs again, but know that there is a fly in the ointment… They are very likely to be energy inefficient and can only be sold due to a loophole where manufacturers state that “these lamps are not for domestic use”.


It is possible to dim a halogen lamp. A halogen light bulb is like an old-fashioned incandescent light bulb, but with a longer lifetime. How is this done? A halogen is one of the following elements: fluorine, chlorine, bromine, iodine, or astatine. The halogen light bulb contains inert gas with some small amount of halogen. The tungsten filament in combination with the halogen gas leads to a so-called halogen cycle chemical reaction. This cycle redeposits evaported tungsten to the filament. This extends the lifetime of the bulb.

Now, what happens when a halogen lamp is dimmed? The temperature can be reduced so much that the halogen cycle gets disrupted! This means that its lifetime drops to that of an ordinary incandescent light bulb. In other words, yes, you can dim a halogen light, but try not to!


We have not encountered a LED lamp that is supposed to be dimmable without being able to dim it. Note that if a LED lamp explicitly states that it cannot be dimmed, this is indeed not possible!