Led color control w rotary switch?

I am working on a project to rewire an old industry hair dryer into a funky floor lamp. It has a cool panel on the back that would fit some kind of a rotary switch. 

I would like to use an existing product or products to emit blue light and yellow light from the bell of the dryer. The rotary switch would allow me to ramp it from the blue leds to the yellow leds with some cross over in the middle.

my challenge is that, while I understand basic electrical circuits, I know very little when it gets into the more technical circuits and arduino stuff. I want to learn but this isn't the project for it.

does anyone know of an easy way to set this up? 

My  thought was a set of blue strips, a set of yellow strips and a rotary controller. But, I don't know what to search for online.


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steveastrouk7 months ago

Are you looking at the 12V nominal running voltage strip ?

How much current will the strips take ?

mckeephoto (author)  steveastrouk7 months ago

Yes. I was going to snag a blue tape and a yellow one and wrap a spiral around the inside of the barrel.

I also was going to power them w the 12v wallwart.

I don't know how much the strips can handle.

Typically 1A/metre. I'd buy two of these:


And replace the pots with something like this :


Wire the pots 1:1 2:2 3:3 on one pot and 1:3 2:2 and 3:1 on the other.

Without some additional messing about, adding a series resistor to limit the output volts, you'd want a 14V power supply to run it all.

mckeephoto (author)  steveastrouk7 months ago

Wow, okay. That looks cool. Thanks for the suggestion! That sounds like it would work for just dialing in the color temp. However, my plan is a little more complicated (like usual).

Below are the photos of the hairdryer project. I want to have one rotary switch in the back that dials from blue to yellow. The led strips are going behind the holes on the bell. And the center hole is going to get a regular Edison socket for an "antique " style led bulb. That will probably be controlled by a simple toggle that I will have to drill into the housing somewhere.

@steveastrouk how could we modify the circuit you described so that it only had one pot to twist? And, by we, you know I really mean you, bc I got no skills in this area! ;-)

mckeephoto (author)  mckeephoto7 months ago

Ah, a little light bulb just turned on! Thanks Steve! Dual pot. Makes sense now.

I think I got it and put together a wiring diagram of sorts. Crude, but I hope you can see the idea. Would you please check my layout and let me know if you think it will work?

I think I am doing something wrong with the negative path, tho. Should it go to one of the pot terminals on each pot? My research is a little vague here. Most of the online photos of a dual pot layout are talking about audio set ups.

And, the 5A DC/DC stepdown led drivers keep the voltage up but slow the cycles to make the leds appear dimmer?

I have ordered all the parts!


Here's what I have in mind.

You have to remove the adjusting control on the power supplies and replace them with the dual pot's action.

mckeephoto (author)  steveastrouk7 months ago

Ah! That's the blue box with the 123 T and W 503 on it, right?

Does this mean I need two 14v inverters? Bring the 110v household in and split it to the two inverters.

Or can I bring the 110 in to one 14v inverter and then split it as it comes out of the inverter?

Will the number of amps I need be reliant on the number of meters of led strip or is it maxed by the needs of the DC/DC controllers I am hacking, which handles 5amps, I believe?

Thank you so much for the drawing! It helped a lot!

Yes, the blue box with 123T on it. 503 means 50K, which is the dual pot I said to get.

Just use one supply. The amps you need are determined by the TOTAL length of yellow+blue strip. I chose 5A regulators as a conservative choice, 10 metres of LED strip is a LOT !

mckeephoto (author)  steveastrouk7 months ago

yeah, even with the wrap, I am probably under 3 meters. I will Measure how much I use and then order an appropriate power supply. I can't wait for the parts to get here. My son is thrilled bc it means that I will clear a project off of our shared work space!

Thank you very much for all the advice!

I'll sketch it for you later.


mckeephoto (author)  steveastrouk7 months ago

Swing and a miss, eh? Thank you!

There IS only one pot to twist, one way it goes blue, the other it goes yellow.

steveastrouk7 months ago

Just switching Blue, blue and Yellow, yellow only would be easy, but is that all you want ? What current do you need for the LEDs ? I'd buy two off the shelf LED dimmers, and modify their controls to use a dual potentiomeyer, with one track wired the opposite to the other, so the control runs full blue to full yellow, and mixes in between.

mckeephoto (author)  steveastrouk7 months ago

this is where my ignorance starts to really shine. That sounds good in theory but it is out side my rather shallow skill set. I was going to get some led tape, wrap it around the inside of the duchess barrel and wire it to the rotary switch. I don't know voltage and the last potentiometer I played with was the volume knob on the cigar box amp my youngest and I built.

But that would be old school and without any complicated programming....

mckeephoto (author) 7 months ago

@downunder35 that is the challenge. I saw those controllers and have used a couple on othe projects. But they are pretty utilitarian/ugly and take you right out of the magic of this old hair dryer. My son had one from ikea that had a rotary type controller that might have been adapted, if it hadn't been destroyed due to his tinkering.

I want to keep the same vintage 1940s-50s feel from the hair dryer wither the controller by using the existing control graphics, a rotary switch of some kind, and a vintage chicken head knob.

The dryer is a huge vintage helen Curtis duchess salon style. And the goal is to covert it to a funky lamp. I'll try to post a picture soon.

Downunder35m7 months ago

You can find a lot of controllers similar to this one on fleabuy.
Might not have any rotary switch or potentiometer but allows to change settings with a bit more comfort.
Does not really matter what colors you connect as long as you know where to find yours on the remote.
But I do suggest to add a connector as it is easier to solder the single strips to it than trying this on the controller itself.