It wasn’t that long ago that you couldn’t even buy a dimmable LED bulb, but now they’re becoming more and more common. So, what changed and why does it matter?</br></br><strong>Basic LED Mechanics</strong></br></br><a title="LED Light Bulbs" href="http://www.atgstores.com/lighting/light-bulbs/led-light-bulbs/" target="_blank">LED bulbs</a> create light through the movement of electrons (and resulting photons) in a semiconductor material, the whole of which is called a light-emitting diode. These tiny diodes, or LEDs, are then clumped together to make light bulbs.</br></br>This is very different from their <a title="Incandescent Light Bulbs" href="http://www.atgstores.com/lighting/light-bulbs/incandescent-bulbs/" target="_blank">incandescent</a> or <a title="Fluorescent Light Bulbs" href="http://www.atgstores.com/lighting/light-bulbs/fluorescent-light-bulbs/" target="_blank">fluorescent</a> counterparts, which ignite filaments and gas, respectively, to create light. In these designs, a dimming effect can be created by manipulating the amount of current to the bulb – but it wasn’t always so easy with LEDs.</br></br><strong>Dimming LEDs</strong></br></br>Generally speaking, an LED is either “on” or “off” by design, and a drop in current (as determined by voltage) will simply shut the light off. So, the question became how to dim a light source that, at the time, couldn’t be dimmed.</br></br><em>Pulse Width Modulation (PWM)</em></br></br>One answer is pulse width modulation, or PWM for short. PWM creates a “dimming effect” – an illusion – by rapidly switching the LEDs on and off to create a flicker the human eye perceives as dimmer light.</br></br>This effect is created with a fixed current (voltage), which makes it easy to adapt to existing switch technology. And, that means it’s a less expensive way to make a <a title="Dimmable LED Light Bulbs" href="http://www.atgstores.com/lighting/light-bulbs/led-light-bulbs/led-features/dimmable/" target="_blank">dimmable LED light bulb</a>, but there is another way …</br></br><em>Analog Dimming</em></br></br>Despite the on/off nature of LEDs, complex circuitry can be added to control the current supplied and effectively dim the bulb while also increasing efficiency. The trouble is that dimming an LED by dialing down the power input may corrupt the light quality produced by the intended current.</br></br>This is because LEDs are designed to operate at a very specific current, and while it’s possible to find the magical space between on and off in an LED, that space is occupied by what your eyes may perceive as less than perfect light.</br></br><strong>Dim Summary</strong></br></br>Each type of dimmable LED bulb has its merits, and both will still save you a significant amount of money over time thanks to power efficiency. Technology and cost savings are likely to improve, but the dimmable LED options available today are already worth the investment.</br></br>If you'd like to know more about how these bulbs can save you money, consider <a title="Contact a Local Energy Efficiency Auditor" href="http://porch.com/local/electricians?tid=social_atgstores_~~_~~_~~_~~_~~_~~_~~_~~_~~_~~" target="_blank">contacting a local energy efficiency auditor on Porch.com</a>.