Author Options:

LED dimming and color temperature control (variable white LEDs) Answered

I'm trying to find an inexpensive way to control a variable-white LED strip with knobs. There are tons of remote dimmers and wall-touch-controls available. These are way too complicated or too big for my application. All I want is two knobs. One that controls the brightness of the LED strips and one that controls the color temperature between the cold and the warm white LEDs

I did some research and see two possible solutions: a) 100% analog using potentiometers and LED drivers or b) using potentiometers, Arduino, and LED drivers. Here are the details:

a) Analog:
- Use two LED drivers to drive the actual LEDs, like these ones: http://www.ledsupply.com/led-drivers/buckpuck-dc-led-drivers
- Use two dual-channel potentiometers to control the brightness of the two different LEDs in the strips:
  - One controls the brightness for both channels (connected to the same pins)
  - One controls the relative brightness between the channels (connected to opposite side pins)

b) Using Arduino:
- Any Arduino with analog inputs
- Two single-channel potentiometers connected to two analog inputs
- Some software that generates the correct PWM outputs for the two LED channels
- LED drivers that can dim using PWM signal input. According to this post, the same BuckPucks can do that, too: http://forum.arduino.cc/index.php?topic=14603.msg107089#msg107089

Do you have any advice on these options? Is there a third one or even an off the shelf solution? What about compliance and certification? If I use BuckPucks and other components that are certified, do I still need a certification for the whole system? (assuming I want to use the design not just for my personal pleasure)


The forums are retiring in 2021 and are now closed for new topics and comments.

4 years ago

Hey! I'm curious! Did you find a way to do this on the analog side? I am trying to make a flicker free (video) Intensity/Color Temperature controller for LED strips.

Suraj Grewal
Suraj Grewal

5 years ago

just a simple 555 timer with a dial to vary duty cycle is best (in terms of cost)


5 years ago

As soon as you start doing something that is not just for you but something you get money for safety is an issue.
For obvious reasons using a slightly oversized LED driver with analog input and a potentiometer is the best option.
Arduino and some code does basically the same and would be only worth the extra if you want to do more than just dim the lights.
For example use fixed settings depending on the time of the day, quick selections and so on.

If you keep all as a kit it is enough that the parts are certified as the one putting it together is to blame if done wrong.
If you sell it as a complete system you have to stick to the electrical safety rules and laws, provide the right power supply, include the appropriate warnings and so on.