Power Supply Diagram

Hi All,

Wonder if someone can check this circuit diagram for me and make sure I am going down the correct route. I am creating a controller to control two sets of LEDs. One 24 strip, and one set of 12v uplighters.

I am using a Micro. This is what I have so far. The individual components are linked at the bottom. My background is software engineering so the diagram might not be perfect and hence why I am double checking. Note I have left off resistors, capacitors, MOSFETs etc for now for clarity as I am just focusing on power.

So I have a 150w 24v LED driver wired to the mains. From that I am using a step down converter to 12v to power the arduino and the uplighters. Then a buck converter to output 3.3v for the fussy ESP8266. Grounds all wired together.

Does this look sensible? One possible mistake I have made is the LED driver is rated at 150W. The LED strip was quoted at 14w per meter. However, what I missed was the RGBW version which I have is rated at 23W per meter. So the LED strip and downlighters are already taking me over 80%. Although only slightly and I doubt the Arduino and ESP board will draw much. But possibly I need a higher rated driver.

Thanks all

Parts (I am ony allowed 2 links as new user so have put a dash in front of the others)
LED Strip - -downlightsdirect.co.uk/ip68-led-tape.html#description
LED Uplighters -www.nationallighting.co.uk/ikon-pro-cct-led-decking-kit-x10-35mm-ip67-280lm-3000k-4000k-stainless-steel
LED Driver - -www.amazon.co.uk/gp/product/B07WCP72NP/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
DC Step Down - https://www.amazon.co.uk/gp/product/B07ZV76NLC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Buck Converter - https://www.amazon.co.uk/gp/product/B07DJX97MS/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

I think the LEDs are turned the wrong way. They also need current limiting serial resistors. Go for some 10 mA.

Uhm, what I see in that schematic is that pretty much every supply voltage is shorted to ground :wink:

1 Like

I'm gonna blame the software on that one. Wouldn't dock where I wanted it and I just threw them on.

That aside, is the fundamental mechanism for splitting the input voltage across the required components sound?

Yes, nothing wrong with what you are proposing. Personally I would power the 3V3 converter from 24V, not from the 12V, but this is a small point.

You need to be careful with the ground wiring, there should be a single connection point, or star point, with the ground wires all coming together at that point. That point is then your 0V reference for everything.

You might like to try either Eagle or KiCad .


Perfect, thanks. I'll take a look at those other bits of software for circuit diagrams. Probably need to read up on how to draw them properly also :smile:

This makes absolutely no sense.

You go to much sphagettification to connect the grounds that your schematic is illegible.

Just show the power and we will assume (well, most of us) that the grounds are properly connected.

On the other hand, just use a pencil and paper.

What is the function of the ESP?

1 Like

Yeah as I said above it was new software and it wouldn't do what I wanted. I should have deleted them

The ESP board is for WiFi connectivity. I know there are arduinos with onboard WiFi but I bought a job lot of micros a while back and these boards are cheap. The WiFi is to make it an IoT thing managed via AWS. I can then create an Alexa skill to control the LED.

I strongly discourage using the ESP as a WiFi "shield" for the Arduino. Just use a board with WiFi already on it, like the $5 Wemos D1 Mini.

What "control" do you want to do? Just turn the LEDs on or off? Then you don't need the Arduino. The ESP is more than capable of controlling the LEDs. (And it has WiFi already).

1 Like

When you figure this part out, please check back here. I have dabbled with AWS skills programming off and on for the past year and find it absolutely bewildering.

1 Like

Well that's my background so happy to help. I've been in software engineering for 20 years and although a manager these days still like to keep my hand in. Use AWS a lot at work and home.

Working on another project with a RaspberryPi to create a ring style door bell. It takes a picture uploads to an S3 bucket, lambda function the pics the picture sends it to Amazon Rekognition which does facial recognition. If it can't identify the person it will give a variety of information including gender, age, facial hair, mood. Working on the final part to send the picture to an Alexa screen.

So yeah give me a shout if you need anything specific

So On/Off, colour selection, dim. Also plan on adding an MSGEQ7 to do music sync as well (mostly because the kids said I couldn't do it)

Bloody hell those D1 boards are £2.50. I hadn't heard of them.

Got some other IoT ideas in my head and they will be perfect for that.


Why not work with a schematic capture program, there are many available and for free. The end result is we understand what you are putting forward without trying to correct all the mistooks generated by or left out by the drawing program.

1 Like

Let's take this topic off the thread. I'll send you a PM.

That's the best reason. In the immortal words of Sheldon Leonard: "Challenge Accepted".

Look at WS2811 or WS2812 programmable LEDs. I have a Christmas decoration with almost 1,000 LEDs that is controlled with one data pin on a Wemos D1 Mini. (Yes, purists, I use a level shifting chip for the 3.3V data).

The MSGEQ7 looks interesting. I could run the Xmas music into it to get the bandpass values to control the patterns of different areas of the LED array.

Challenge accepted.

Hi, @iwaters
Welcome to the forum.

Your effort at a schematic is praise worthy, it get to show us the basics.

Can I suggest you abandon the CAD for the moment, and draw your schematic clearly with pen(cil) and paper.
Your mind and hand have more component symbols in them than any CAD.

Your diagram has many crossing wires and are any of the wires connected to the micro.

You need to label the pins on your components, "IN/OUT" on ALL pins is not very informative.

Thanks..Tom.. :smiley: :+1: :coffee: :australia:

Finally got round to wiring everything up. Excuse the mess of the breadboard, but hey it works.

One small question. When I plugged everything in, with a blank sketch loaded on the board, the LED strip was all on. No problem I can analogWrite 0 to each pin to turn everything off as its start point. But is that the correct way to do it? What I mean is power and the aurdino will be "always on" ready for a command from Alexa. Does it need a relay to cut power to the LED strip when not in use, or are the MOSFETs on each colour channel doing that anyway?

1 Like

When you deploy the project, why would there be a "blank sketch"?