LED Dimming Explained

You might have heard the term PWM referred to when talking about dimming LEDs, but what is PWM?

What is PWM?
PWM stands for 'Pulse Width Modulation' and is simply a method of controlling power delivery to an electronic device. In the case of LED products such as Pixalux, PWM is used for dimming LEDs, and controlling the colour of  CW+WW and RGB LEDs.

How does PWM work?
PWM controls the brightness (or colour) of the LED by controlling the duty cycle of the output voltage - this is the amount of time the power is on relative to the total cycle time. For example, having the power on for only 50% of the cycle will result in a reduction of brightness by 50%. The same principle applies for coloured LEDs where the red, green, and blue channels are set to different intensities in order to achieve different colours. 

How mixing red, green, and blue channels can create different colours.

How mixing red, green, and blue channels can create different colours.

In the animation below, the green segment shows the pulse width being modulated. As the width of the duty cycle is increased (widened) you can see the intensity (brightness) change correspondingly, as depicted by the red curve.

By Yves-Laurent (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons

By Yves-Laurent (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons

We're excited to be providing a new range power supplies from Meanwell that integrate PWM dimming for use with a compatible dimmer unit. This eliminates the requirement for any extraneous control systems such as drivers or remote controls. You can find out more about this range of power supply and PWM here.