Universal High-Power LED Driver with 3D-printable Case

*** There's a firmware update. Please check out! ***

LEDs are taking over conventional lighting every day. High-power LEDs over 1W are becoming more and more affordable, and I wanted to start using them to replace the lighting fixtures around me. However I realize that finding and configuring the power supply was a bit of a pain, since I wanted to use different LEDs in different configurations depending on what the lighting was for. Power supply needs to regulate the current that goes though the LEDs. With higher current that high-power LEDs require, active constant current circuit is the only practical option. Commercially available buck regulators are easy to use, however, they are usually made for a specific current and voltage range. For me that means having to purchase variety of buck drivers.

Also, most of LED drivers lack dimming function, or have poorly functioning dimmers. I think dimming is essential for modern lighting, and I want smooth control of brightness.
So I decided to develop a universal, dimmerable high-power LED controller. It has taken me four months to develop this controller. Although it's still in development, I think it's quite useful to all DYI'ers with LED lighting projects.

I made this an Open Source project. Both hardware and software are open - please use, and extend this project and share the knowledge. A 3D printable enclosure as well as couple of LED mounting hardware is also available as Open Source, download-able at Thingverse. Together you can really kick start LED conversion of your household lighting!

Step 1 Features

Here's the list of main features:

• Inductor "switch mode" controller for high energy efficiency.
• Wide supply voltage range of 5 to 18V (can go higher, but not tested). Great with batteries as well as AC adapters.
• Up to 20W maximum output power (can go higher with active cooling). (at supply voltage 12V or above)
• Constant current (pulsed) - configurable up to 3A peak current.
• Selectable between buck-boost and boost mode.
• Analog style dimmer control (smooth, flicker-free continuous adjustment)
• IR remote receiver - controllable via Sony IR remote control
• Digitally controlled dimming - via external microcontroller including Arduino.
• Master/slave gang dimming - connect multiple units together and control the dimming from any one of the units.
• High frequency pulse drive - 32kHz to 175kHz - no flicker even in video!

Comments

[sangyue]

Hi Aki,

Thank your very to share your projects. It really brings a lot of fun to my life. I made your universal High-Power LED Driver and it is working great. I bought a PICKIT3 from Microchip and tried to add some code for the IR remote control function. Now I could use '0-9' button to adjust the brightness to the pre-set value and turning on the light by cliking the 'Power' button.

I am a novice for the PIC micro-controller, I am not quite clear about how the A/D and comparator usage. I want to use 2 or 3 18650 lithium battery to provide the power. I want to add the low voltage shutdown function to prevent battery overdischage. Could help to give some code example about this function? Say I want to shutdown the light when the supply voltage is under 6V(2 18650) or 9V(3 18650).

I saw the 'shutdown_vol2 equ 24' in your code, but I did not figure out how to check the supply voltage and make action to turndown the light when the supply voltage is too high.

[ledartist]

Look for a variable named "sp_voltage". This variable holds A/D value of the S-SENSE input. 0xFF (255) corresponds to supply voltage of about 28.5V, so you can scale it to the number you need.
Just check this variable at the end of the main loop (note that it takes some time for the first conversion to be done), and shut down accordingly.

Now the tricky part. A/D conversion uses PIC's supply voltage as a reference. So if it goes under 5V (happens when you give lower than about 6.5V to the circuit, because the 5V regulator needs some voltage) the A/D value changes. For us to know the exact voltage on S-SENSE, we need to have a known voltage supplied to the PIC.
PIC has an internal reference voltage you can use to determine the supply voltage (by calculation). You might want to check into that.

[sangyue]

Hi Aki, Thank your very to share your projects. It really brings a lot of fun to my life. I made your universal High-Power LED Driver and it is working great. I bought a PICKIT3 from Microchip and tried to add some code for the IR remote control function. Now I could use '0-9' button to adjust the brightness to the pre-set value and turning on the light by cliking the 'Power' button.

I am a novice for the PIC micro-controller, I am not quite clear about how the A/D and comparator usage. I want to use 2 or 3 18650 lithium battery to provide the power. I want to add the low voltage shutdown function to prevent battery overdischage. Could help to give some code example about this function? Say I want to shutdown the light when the supply voltage is under 6V(2 18650) or 9V(3 18650).

I saw the 'shutdown_vol2 equ 24' in your code, but I did not figure out how to check the supply voltage and make action to turndown the light when the supply voltage is too high.

[captain Jack]

Very nice!

[tphillips2]

Amazing! Now I can start converting my lighting at home and the studio. Impressive job in detailing. Look forward to getting started!

[PedroDaGr8]

Excellent instructable! As someone who is designing a low current higher voltage (into the 100s of V) boost converter it is interesting to read someone going through similar things that I am. That being said, your design makes mine look like crap! Yours is much nicer and much more fancy. Mine is very basic to solve a simple problem.

The only additional thing that would be nice to see is you do a follow up project for converting mains to either 12V (for this) or do a mains powered version of this. Obviously, it would b significantly bigger but it would have a bit more application for this. Either that or since this is OpenSource I may build off your design. I guess its based on what time/funds will allow.

[ledartist]

Thanks your comments!

I'd imagine that voltage that high would be hard to do as a boost converter, since finding MOSFETs with breakdown voltage higher than 100V seems to be hard. Are you using a transformer?

Anyway, 12 - 24V DC power supply is easy to find. Most people have a few wall warts laying around I think. Battery operation is nice too. Add to that as long as I've been playing with electronics, and I even have a electrician license, developing high voltage circuits still makes me nervous...

Please do use my design partially or as whole, to build your projects. Do not forget to share that here on instructables!

[PedroDaGr8]

Its not much above 100V actually (around 120-130V) I just realized I worded that kinda wrong. No transformer, just an inductor.Otherwise pretty much a standard constant current boost circuit. Nothing too special, just designed to work on 8-24V.

Yeah, if I do modify your design to work on household voltages I def will post it on here.

[JVC-Force]

Can it be used with voltage variable dimmer (1~10V DC) that Lutron sells?

[ledartist]

Not sure what that dimmer does. Is it a dimmer or a controller that outputs DC voltage?

[JVC-Force]

It is just a simple 0-10 VDC lighting control dimmer, voltage variable lighting control signaling system.

[ledartist]

Ok, just like old dimming system, pre DMX days.
No this circuit doesn't support such a system, but very easy mod to connect 0-10V dimming voltage to where the pot is. All you need is a resistor voltage divider to reduce the voltage within 5V.

[smldis]

Hello,
What software did you use for that schematic?
I'm searching for a publication quality schematic editor and that seems to suit my needs!
Thankyou

[rocketman221]

A couple of good editors are TinyCad which is completely free and Eagle, however the free version of Eagle only lets you make a single page schematic.
Eagle is cross platform, TinyCad is only for winblows but it runs fine under wine.

[ledartist]

I think schematic from Eagle is just ugly, and very hard to read. I almost tried the free version, but it's too limited. (Don't understand why people would pay good money for Eagle...)

TinyCad looks promising. I might give it a try.

Aki

[ledartist]

I use Adobe Illustrator, and draw schematics from scratch. I mean, I have drawn all the basic symbols, so it's a matter of connecting them.
Not as quick as using a CAD program I bet, but works for me. (I guess I'm cheap.)
Let me know if you have Illustrator and want my symbols file.

Aki

[smldis]

I use pretty much the same setup, because I use inkscape and I use symbols generated from circuit-macros for LaTeX.
I'm happy to know that someone else use this solution,
I haven't find out a better approach. (output quality does matter in my cases)

Samu

[Reffner]

This is fantastic. Adding LED lighting and replacing many of the incandescent lights around my house is something I've been wanting to do for a while, but controllers have been the weak link. I'm definitely going to look further into this. Good job!

[ledartist]

Thanks!
I felt exactly the same - choice of LED drivers are quite limited.

Aki

[jeff-o]

Wow, these are some killer controllers! Very nice work.

[ledartist]

Thanks Jeff! Happy New Year!

[azarpisces]

Looks great project. I m gona explore it further..........