I came across this and I found it pretty cool and nice, it made me want to make one 
(because I have in my old recovery components a led strip which is hiding somewhere)
btw good stuff in his channel cover of Velvet, Joy Div …with its modular !
7 Likes
Not sure I quite follow the whole switch for pot/cv bit.
Seems klunky.
Heavily medicated today so I’ll chalk it up to me missing something obvious.
2 Likes
I have a led strip lying around and I would like to test this circuit but I wanted to know if there is no problem using 60V 30A MOFSETs instead of 30V 60A (that’s what I have on hand)
(the circuit operates at 12V, with really a small strip of LEDs)
thanks
I have never worked with mosfets, but you should never get anywhere close to 30A with your LEDs, so from that aspect it should be fine 
1 Like
30A should be plenty, just make sure the MOSFETs are n-channel and you use the right pins of the MOSFETs.
The Arduino output should connect to the gate.
The source connects to ground.
The drain connects to the negative end of the LED strip.
The positive end of the LED strip connects to positive power supply.
Something needs to limit the current through the LEDs, either a resistor, or the power supply must have current limiting, or the way the LED strip is built.
2 Likes
Make sure you are exceeding the gate threshold VGS(th) and not exceeding VGS(max)
If you are close to the gate threshold you LEDs will turn on but the mosfet source drain resistance will be much higher than expected and your mosfet will turn into a small heater…
2 Likes
Thanks @sebastian @antoine.pasde2 & @JaggedNZ
yes the MOFSET i have are N channel (some STP36NF06)
i’ve just verified the pin and it’s like the “Plan” drawing with Mosfet seen from the front
and the led’s strip have his own smalls resistors between leds
everything looks good but what worries me a bit is that the circuit is made for an incoming gate signal of 0 to 5V, and I think that some trigger or gate on my Kosmo sends more than 5v
is it critical or not Doc ? how can i protect this plz ?
I think the circuit is designed for control voltages rather than gates as the jacks go to analog inputs.
Either way, you can protect the Arduino inputs with a resistor and Schottky diodes to the Arduino power supply and ground. A 1K to 10K resistor should be good.
1 Like
Anyone tried WLED?
It works on led-strips and the latest beta also on matrices. I’ve implemented WLED on a few 3D-printed pillars / columns each containing a 16x16 WS2812 led matrix.
The software is very versatile and simply amazing. Here is an impression of the pillars / columns:
There appears to be a sound reactive fork of the code:
4 Likes
I’ve literally just finished helping my 12yo with some FastLED code on an Arduino nano. We are trying to get some WS2812B LED strips to turn on/off when he turns his “battle station” on/off plus adding a bunch of effects. FastLED is the library doing to actual LED control underneath WLED, it’s both simple to use and has a wealth of functionality when you dig into the documentation.
@Dud I’d also recommend @antoine.pasde2 solution. If you wanted to risk it, you could through a resistor between the jack and the gate and trust the internal diodes on the Arduino to do their job, but you are risking the Arduino for the cost of a few schotty diodes…
BTW with the mosfets the Vgs is +/-18v and threshold is 2.5v max. It would be safe to feed eurorack signals directly to those mosfets!
2 Likes
Thx @antoine.pasde2 , @JaggedNZ , I have some 1N5817, that can do the job ?
Yes, 1N5817 is perfect.
1 Like
They should work just fine.
Explanation: What you are looking looking for is a diode with forward voltage drop of around 0.25v so if the input exceeds supply voltage (idealised to 5v) then the input will not exceed 5.25v (supply + forward voltage drop) or -0.25v below the negative rail.
Common diodes have forward voltage drop of 0.6v which will only clamp to -0.6 and 5.6v for our example which would exceed the max voltage for most gpio pins.
2 Likes
I actually have a project that uses led lights and an esp32. This will save me some time, thanks!
1 Like
The circuit works, tested and boxed !
and now construction of a wooden box then paint to contain the led strip, and test of different transparent materials but a little opaque for the diffusion of light, I found in my garage a piece of plastic tarpaulin which should do the job.
1 Like
Seems interesting. Planning to light my case with a led strip that I would like to be able to control. Guess something like this would work
1 Like
Done, here’s all my building stage
i added a power switch with an indicator led to the circuit
all in a box with some paint and hot glue
add a power socket too
first test, all work fine
but I found that we saw the leds too much, a light that was not diffuse enough
with a second layer of plastic it was much better, so I built a mini wooden case, which I painted and fixed the tube inside
second test much better
and to finish this endless post, a short video in action triggered by the kick
11 Likes
just realized I bought 9m of these lights by accident, along with some 3A 12v power bricks, so i can put them to good use with this.
Just a question about the mosfets, the build guide says to use a 60v/30A, but all the ones I see on the online stores which are 30v seem to start at 100A, I’ve never worked with MOSFETs before so I am clueless, would they be ok?
The rating of a MOSFET specifies the maximum current it can handle.
So a 100A transistor will be fine with the lower currents of your 3A power supply.
You should be able to find lower power MOSFETs though, and they should be cheaper than the 100A ones.
Just make sure that their threshold voltage (Vth) is lower than the output of what your using to controlling it (e.g. the 3.3V or 5V output of your micro-controller).
3 Likes
Thanks @antoine.pasde2 , that certainly helps 
1 Like