Whether you are using them to light your room, accent your kitchen counter, or show off your garden pond, LED’s are a great for many different lighting applications.
Compared to the older conventional light bulb, LED lights are much more efficient and have a longer life span.
They come in a variety of forms such as bulbs, strips, flat panels, or just the individual LED itself.
You are not limited to the color options as LED’s have a multitude of colours to choose from (colours that cover the entire color spectrum visible to the human eye).
Dimming the lights is a great feature to have in rooms off your home. It can provide a different ambiance and set the mood for different occasions.
So, can you dim LED lights?
Since there are many types of LED lighting options available, it all depends on what kind of LED lighting is being used.
For LED light bulbs, which are connected to light sockets in your home, most LED light bulbs are dimmable. However, not all of them are, and they do not all operate in the same way.
You then have your LED strips, and individual LED’s that run on lower voltages and do not get connected to light sockets. These types of LED lighting can be dimmed by simply lowering their voltage (or connecting to a controller circuit that can dim them).
Since you cannot lower the voltage of a LED light bulb, you need special dimmer switches to carry out this task.
In this article I will dive deeper and cover more information regarding what kinds of LED light bulbs you can dim and what is involved in dimming them.
What is dimming?
Dimming a light is essentially the ability to change its brightness.
A normal light in a household which does not have a dimmer circuit, would be operating at its maximum brightness when turned on.
Dimming allows the brightness to be varied from 100% all the way down to 0% (which looks like it is turned off but it is not).
Sometimes having the lights at full brightness can be quite annoying as they can have an effect on your eyes overtime. Having the ability to dim a light source can be beneficial.
By dimming the lights you lower the amount of power consumed by the light therefore cutting costs to your power bill.
What is a dimmer?
Being able to dim your lights does not just happen by magic.
It involves something known as a dimmer circuit. Their purpose is to allow you to be able to alter the brightness of your lights.
The way the dimmer circuit does this is by changing the voltage waveform applied to the light.
The dimmer circuit rapidly shuts on and off, reducing the total energy that the light bulb receives. The lower the energy the lower the brightness and the higher the energy the brighter the light bulb.
Dimmer circuits are generally used for light outputs that include incandescent bulbs, halogen bulbs, compact fluorescent lights and Light emitting Diodes (LED’s).
Older dimmers were built using resistors. Resistors are not the most efficient way of dimming circuits due to the fact as the resistors heat up, a lot of energy is lost.
Therefore, modern day dimmers are built from semiconductors to increase the overall efficiency.
Types of Dimmers
Through the years the dimmer has seen many upgrades from its humble beginnings.
It all started with the Rheostat Dimmer. This type of dimmer primarily used a rheostat (of course!).
A rheostat is an electronic component used to control the flow of current by varying its resistance.
This type of dimmer was inefficient because a lot of power was lost through heat. They were large and needed cooling air to reduce the heat.
Also, due to the fact they had mechanical parts, they were slow, again adding to its inefficiency.
A common early use of a Rheostat dimmer was the Saltwater Dimmer which used a liquid as a form of varying its resistance.
Next came the Auto-transformer dimmer. Also sometimes referred to as a VARIAC.
Though the Auto-transformer was as large as a Rheostat dimmer and were quite similar in resemblance, they were more efficient.
The output voltage which is used to vary the brightness of a light, was independent of the load applied in an Auto-transformer. This led to easier design of the lighting.
Nowadays, Auto-transformers are no longer used for dimming applications.
Lastly we have the Solid-State Dimmer. The solid state dimmer uses semiconductors to perform dimming.
They were developed in large part to reduce the problem of inefficiency that were present in the Rheostat and Auto-transformer dimmers.
The main benefit that reduces the dissipation of power is that solid state dimmers switch the voltage rather than absorb it.
It also has the added benefits of being controlled remotely and small enough to be embedded inside a household light switch.
Application and Benefits
Having the ability to dim the lights can have many advantages.
Light levels in a room can affect your mood without you even knowing. It affects things like the way we work, and the way we feel.
The softer the light level the more comforting and relaxing. While brighter light levels are more stimulating and good for keeping you awake.
Softer lighting is great for setting the mood for things like watching a movie, or having a romantic dinner with a loved one. Or, maybe you are someone who likes sleeping with the lights on. A softer light will solve this problem and eliminate having to try to sleep under light that is at full intensity.
Brighter lighting is great for when you need to do work or need a good amount of light for reading.
Having different rooms that have different light levels is not ideal, but, the light dimmer is the perfect solution.
You can have the benefits of softer and brighter lighting all in one room.
The Light Bulb
One of the main pivotal points in history was the invention of the light bulb. We can thank Thomas Edison for that.
Before the light bulb people would use candles to light up their homes so they could carry out tasks like cooking, bathing, reading etc.
While candles were handy, they were not the most effective, as they only lit small spaces at a time.
Light bulbs allowed one to light up more areas in their house at the flick of a switch.
The dimmer circuits that we have covered were used in conjunction with these older incandescent light bulbs.
Over the years however, light bulbs have evolved from the older incandescent bulbs to newer more efficient Light Emitting Diodes.
Light Emitting Diode
If the incandescent bulb was a crucial invention in lighting, the Light Emitting Diode (LED) was a crucial innovation.
Compared to Incandescent, Halogen and Compact Fluorescent bulbs, LED’s require far less energy to operate.
They use 75% less energy to run. This means that in the longer run you save more money on your power bills.
They also have a longer life span, again saving you money by having to buy less of them.
A LED is a tiny semiconductor known as a Diode. A diode is a device that restricts the flow of current in one direction.
This flow of electrons creates photons (which is the light we see).
LED Light Bulbs
So, you can see the many benefits of using a LED light bulb.
But, can you dim all LED light bulbs?
It all comes down to two factors; whether the LED light bulb is designed to be dimmed and whether your dimmer is LED compatible.
Not all LED light bulbs are designed to be dimmed. The ones that can be dimmed are designed with a special circuit embedded inside them that allows their brightness to be varied in response to a varying current.
So, your ability to dim a LED light bulb all depends on this factor. When buying a LED light bulb, you need to verify that it is ‘dimmable’.
Most of them will state this in the title, or you can check the product description.
So you have a dimmable LED light bulb. But, what about your dimmer circuit, will it be able to dim them?
There are two types of dimmer circuits; Leading Edge and Trailing Edge.
Leading Edge dimmers are designed to work with older incandescent bulbs. These sort of dimmer circuits would be found in older households.
These types of dimmers were designed to work with traditional bulbs due to the fact that they were higher wattage. Since LED light bulbs are low wattage leading edge dimmers will not be able to dim your LED light bulb.
Trailing Edge dimmers are designed to work in the lower wattage range and therefore can dim LED light bulbs (the dimmable ones of course!).
How do you tell if you have a Leading or Trailing Edge dimmer?
Since, dimmer circuits deal with high voltages, it is not advisable for you to open your light switches and check.
You will have to contact the manufacturer to find out what kind of dimmer circuit you have installed.
You could get an electrician to come and have a look as well. Or, you could just install your LED light bulb and check if the brightness of the light is varied. The worst that could happen is that you blow the bulb.
If your home was built within the last 5 years, and you have a dimmer, it is likely that it is a trailing edge dimmer and compatible with LED light bulbs.
If you have identified that you have a Leading edge dimmer do not worry, you can make the switch (pardon the pun) to a Trailing Edge dimmer.
The cost can range from $60 to $150 and depending on the brand of the dimmer and the cost of labor.
As I mentioned before, for your own safety, it is advisable to hire an electrician to remove and install the new dimmer.
Conclusion
So, in order for you to be able to dim an LED light bulb, it needs to specifically designed to be dimmed.
You can find this information in the product description of the LED light bulb in question.
Also, your dimmer circuit needs to work in conjunction with LED light bulbs.
These dimmers are most commonly the Trailing Edge Dimmers.
Always consult an Electrician if you need to check what type of dimmer you have, or, if you want to replace an existing dimmer to the newer ones.
