The Question on Everyones Mind (ELV Dimmable LED Downlights)

Gday All,

Ive spent the last few weeks binge watching Superhouse and Scouring the web working on plans for my home automation dream :slight_smile:

Slowly been buying bits and pieces, teaching myself Arduino and refreshing my Linux (have a BSc in computer science so that part isnt too bad) but still keep coming back to how do I do dimmable lights.

I’m about to renovate my home theater (over the next few weeks), so will be adding some LED Downlights and probably LED strip lights etc around the place as well as replacing the light switches with the Superhouse ones :slight_smile: and adding a 2nd Switchboard next to my networking equipment, luckily I ran UTP everywhere when i was building the house 15+ years ago…

So I guess my question is what do people think of using a 12Volt DIN mounted Power supply to run one of these on 12V and then running wires up to 12V LED Dimmable MR16 bulbs in the downlight fittings?

Am planning on having probably 6 downlights in the room split as 1 set of 4 and 1 set of 2 (to light my partners home office area at the back of the theater). but hoping to be able to control each downlight seperatly as well if needed. As well as the downlights will add some strip lighting around the place as well as maybe adding some linear actuators on the windows to open and close them to let some fresh air in etc…

Am going to use IR to control the A/V equipment and the Theater screen as It will be going in front of the Windows (only way things will fit) but I have roller shutters on the outside of the windows and the screen pretty much covers the windows completely. So also need to find some way to motorize my old manual winding roller shutters, but I dont think that will be too much of a problem.

I am thinking that since all the electronics past the 12V power supply is ELV than I should be good on Electrical compliance and able to do that part myself although I might talk to a sparky about helping me run some cables up to the lights as I’m not the most agile of 47 almost 48 year olds :slight_smile:

I keep thinking I should go back to Uni and get an Electrical Engineering Degree as well or Robotics is another option :slight_smile: but even then I still wouldnt be able to do my own electrical work unless I do an electrical apprenticeship it seems, I kinda like the US way they handle home electrical work, but we aussies do some strange things lol

I’m guessing since usually the power supplies for 12V lights are located right next to the light, am I going to have issues with the cables being so long? approx 8-10m and does anyone have any suggestions on type of cable? just run 2 wires to each or UTP just in case to future proof :slight_smile:

Anyways thats my idea, not sure on how feasable it is, am working on getting some of the bits and pieces together at the moment to test things out. I guess my major concern is legality and what is feasible and if anyone has a better idea :slight_smile:

My plan is to install a mix of Relays and Triacs, but if I can get away with 12V or 24V lighting I think thats the way to go then I can slowly replace the old style lighting over time in the rest of the house, main thing for now is Automated lighting control, would love to be able to open and close the windows automatically as I only have Evaporative AC here in Adelaide, am looking at adding some reverse cycle split systems in a couple of rooms for when its really HOT, but most of the time the Evaporative keeps things cool and breezy :slight_smile:
I also have a couple of Gas heaters, but they have manual knob like thermostats so not sure how I could automate those.

Anyways hope that ramble makes some sense to people, let me know what you think of the idea, and wether I am completely off the reservation :slight_smile:


Welcome DavydM,

The dimmer in question has written in the specifications that it is a “Leading Edge AC Dimmer” operating at “AC voltage 80v to 240v”.

I am sure this is a point of interest for many in the community, and I will be keep to hear the opinion of others.

Hi there mate,
I am in Perth,WA so have similar issues and ideas to yours, I have set up an incomplete system, but it has allowed me to test differing technologies, protocols and lots of other aspects. Many ideas and methods are influenced by Jon Oxer.
I am an Electronic Tech by trade and certainly not sparky qual in Australia, but was in the UK. I know the rules and regs pretty well here, but will never be qualified due to the way the system is controlled by TAFE and the fact that legistation will need to be changed to allow me to make becoming a sparky financially possible.

To start with I use 13.8V and LEDs through a DMX dimmer (ebay) and MR16s or similar. I do have mains lighting to, but this I do not really control - simply due to the insurance/regs etc.

To give you more advice it is best that you clarify the control method for your MR16’s - lets be accurate about the supply voltage for the MR16s and the control for them. I don’t wish to be patronising in anyway, but if you add a bit of detail about how you want to control the MR16s, and standard mains globes, then I can relate my setup to you better.

You will find Jon talks alot about Openhab as the control system, which I have spent days dealing with, so although not an expert I know lots of time wasting caveats to avoid!

Heres a quick summary of my setup -

Openhab 2 - Raspberry Pi3 (8Gb SD)
MySensors serial gateway (Arduino and RF24 board) this is for temps and long range control of pool lights and spa functionality
Tasmota on Sonoff devices - Wifi connected for shower fans and simple mains control from sockets
ESP8266 with 433MHz transmitter for standard old Jaycar mains switchs
DMX dimmer 24 channel
ARTNET to DMX converter using a ESP8266 chip

Thats the system so far, its due for overhaul shortly which will include using existing mains light switches without interfering with the mains wiring so Everyone can use the system without a phone and the most important factor is that I will then be able to extract the system should I move house. Its amazing how unsellable your house is when its a superhouse!

Just keep asking the questions

Chris H

Gday Prof and Chris

Thanks for the Welcome and the info :slight_smile:

I guess I am also at the planning stage, trying to decide on the best technologies and bits and pieces, although at the moment as I said Im renovating my home theater, and it just so happens that the ceiling in my garage decided to collapse and fall down a couple months ago which is next to the theater sharing a wall, so I have excellent access into the roof space until I get around to fixing the Garage ceiling :slight_smile:

Ive spent the last week or so scouring e-bay and places buying bits and pieces to test out, just waiting on some strip LEDs and MR16 downlights to come in from China, but managed to score a 155" electric screen for the cinema for $140 I think my current 120" cost me 3 times that much when I got it, so thats one of the things I want to automate in there…

I’ve purchased a few Amazon Echos, Echo Dots a Spot for the bedroom and a Echo Plus, and a couple of Phillips Hue globes, but I really want to stay away from Wi-fi as much as possible I could get some Hue Downlights for the Theater but I would need 6-8 of them at $70 each bit extreme, I also plan to add some LED lighting strips around the place as well, which I am thinking I will control with an Arduino, I need to get a couple of Ether Megas, so I can do POE and hook them up to MQTT and openhab, as well as Elexa for voice control, but I have my 84 year old mum who has parkinsons living with me so I want to also be able to control things with a button on the wall. It seems every home automation gadget coming out these days expects you to carry your phone around with you everywhere and for me I get home my phone goes on my desk and it dont move for the night :slight_smile:

I got a few IR recievers and transmitters the other day so am playing aroudn with them to capture IR signals and allow me to use a remote to control multiple devices, especially in the theater I only really use 4 buttons, on/off for the projector and on/off for the amp and vol up and vol down, but have these 2 remotes with 50 buttons on them that I never use, so planning to go down to a real simple remote like the ones that come with arduino kits :slight_smile:

Have setup OpenHab 2.0 on a raspberry Pi, so just starting to play around with that as I get some devices to control, also been looking at using RF to control ceiling fans and some older style belkin power plugs that I bought years ago, bought a RF transmitter and reciever on the way home so playing around with that at the moment, figure I can also control garage door and a few other things around the place with it…

There are just so many options out there for home automation its difficult to work out what to go with…

But taking Jonathan’s advice seems the best to me, less Wi-Fi more wires and buttons on the wall for visitors and non tech family members is the best aim I think, It’s pretty bad when people come to visit and you have to train them to use your house, things should be as intuitive as possible at a minimum give em a button to press :slight_smile:

What I’d like to get done out of this Theater renovation is downlights in the ceiling, LED strips around the room, both that can be dimmed, automate my screen going up and down and open and closing the roller shutters on the windows, would be nice to also automate the curtains, and add some linear actuators to open and close the windows, and IR transmitter to control my projector and amp. Of course all of this needs to be controlled either via alexa, IR remote, button on the wall or openHab automation or from openHab on my phone. That what I am hoping to do :slight_smile:

I will keep experimenting and any advice and help is greatly appreciated, for the time being I still have to finish painting the walls in the theater and organise for new carpet to be laid, so I have a few weeks to get the home automation stuff sorted out, it should be pretty cool when its all done, just be interesting to see how long until its all as I want it :slight_smile:

Gday All,

Bit of an update, so I got enough bits and pieces in to do some testing using an Arduino with a DMX Shield to control the DMX Dimmer (can get cheaper from China, but didn’t want to wait) to control 2 x 12V LED downlights from China, have another 6 coming soon :slight_smile:

which looks a little like this

I have a simple sketch running on the Arduino to dim channel 1 and do the inverse to channel 2, need to play around with the values a bit as the Downlights seem to only dim visibly when the voltage gets down to around 5V, as you can see in this video

Going to use some in wall speaker cable to hook up the lights and just need to find a 12V power supply to run them and all should be good :slight_smile:

So I’ll be able to run 8 downlights off the DMX dimmer, leaving plenty of room to expand as they will only use 8 of the 24 ports, also have some RGB LED strips in the theater so will run them off of the dimmer as well although RGB will take 3 channels 1 for each colour…

Now just need Jonathan to get some breakout shields and RJ45 Shields in stock so I can make the light switches and board to control it all :slight_smile:

Just when I think I have my lighting figured out, along comes something that excites me and confuses the situation more. I really like the DMX control idea. Using china parts, I could build a whole house, low voltage lighting system for a little more than my 110v arduino, relay system. Since all of the lights and control systems would be low voltage, I don’t think that I would be under the inspection cloud that has been hanging over me, since I started my project. Low voltage systems come under a whole different set of rules and basically, you only need to use the correct UL approved wire and power supplies, to be inspection ready.

The only problem is getting 12v lighting fixtures to install. Since I am using can lighting (down lights) for almost all of my lighting, that might not be too hard since I have seen more UL approved lighting on amazon that uses a separate power supply, that could be removed and reused elsewhere. I don’t want to be stuck with having to buy all of my lights from china because none of them are UL approved and that might be a sticking point with the inspector. Although, I don’t know if low voltage lights are required to be UL approved, like 110v ones are.

Since I am wiring all of my lighting, using home run wire to a central location, I could change to a 12v lighting system very easily. I am using no 14-2 romex for most of my lighting and most circuits ar not over 40 ft. from the panel with most circuits having no more than 2 fixtures on a circuit. I used 14-3 on some circuits to control 2 fixtures, rather than using (2) 14-2 wires. I have lots of 14-3 wire left over since I abandoned using standard light switches and went with Jon’s Superhouse push button lighting. Using cat5 instead of 14-2 or 14-3 saved me a ton of wire since I have at least 2 or more switches in every room. All of the 3 and 4 way switch wiring was really getting complicated and a pain to get right.

Can anyone tell me if no 14 solid wire is ok for a 12v lighting system? I could use # 12 wire but as I said, I have lots of 14 left over. Since most LED lights seem to have # 18-16 stranded wire from the 12v power supplies, I would think that #14 wire would be more than sufficient.

I need to read more about DMX lighting to see if it is as suitable as I think for my lighting control needs. I have read that it is only one way communication, like the old x10 system, in which case there is no lighting state verification. Not the best situation but, unlike x10, there is no command delay and lighting happens immediately. Also, I saw a 30 channel DMX lighting/dimming controller on AliExpress for $36. Since there is a lot of theater and club lighting, DMX controllers are reasonably cheap and computer control is well documented, you just need to use 12v low voltage fixtures.

I’m looking forward to hearing more about your DMX lighting project. As I said, It would be easy for me to change over my 110v design to 12v, at this point but I need to make up my mind soon, (or else go crazy). Also, I did run across a 110v DMX dimmer, for controlling 110v LEDs and it too was a 30 channel and under $50. So many choices, so little time.


Hi @DavydM.

In that video, how were you using the original LED’s drivers with the DMX slave? Mind drawing a wiring diagram?

My previous house was completely on LED down-lights with DMX slaves built in, but required a bank of noisy DC transformers to power them all. And waiting times for shipment of replacement LED slave units if they failed.

For my current home I’ve been investigating using standard LED down-lights, as seen in your video. Using PWM on the DC lines from the LED’s original transformers, with a FemtoBuck LED driver controlled via an Arduino’s PWM pins.

But the advantage of DMX is not running out of PWM pins of the Arduino to do the whole house. And can daisy-chain a single DMX data line throughout the whole house to each DMX slave. Disadvantage is having to use and wire external DC transformers.

The down-lights have warm/cool “modes”. Which you could control via the DMX channels (V+, R- cool, B- warm).

So I’m stuck weighing the pros/cons of DMX vs femto buck. If you are some how powering each LED with it’s original transformer and dim with the DMX slave then that solution out weighs a femto buck. :smiley:

Hi DavydM,

How is your LED via POE project going?

Also, did you consider using a POE enabled switch? You can pick up used industrial equipment very cheaply on ebay (at least here in the US). I found a 360W, 24 port HP for $40US.

Thanks for any info/update

I’ve been playing around with DMX for my own setup. Was originally hoping to use the LED’s original driver to do 240VAC to 12VDC for each downlight to use the existing 240VAC ceiling wiring. But I’m guessing each driver was doing it’s own PWM and/or regulating the current, conflicting with the DMX’s PWM dimming.

I will now have centralised transformers running DCV to each downlight with a 3 channel DMX LED driver per downlight (using 2 of the 3 channels: cool white, warm white, natural white is a mix of the two). This allows the LEDs to dim from 0 to 100% smoothly and temperature change all via DMX. Daisy chaining the DC input and DMX input to each DMX unit/downlight.

I’m using these DMX units:

I could be wrong, but it looks like DavydM is using the DMX as the input for each driver which is most likely why he’s not seeing any visible dimming till below certain voltages. The DMX unit should be used as the LED’s only driver. To provide constant PWM’ed 12VDC signal.

I’m using Node-RED to convert iOS’s homekit colour temperature and brightness values into the two DMX channels per downlight (cool/warm white channels).

homekit UI (or wall push buttons > mqtt) > node-red (with homekit plugin) > mqtt > POE EtherTen with DMX master shield

(DMX slave/decoder > LED downlight) x4 per room.

Hopefully I’ll get some time over the weekend to make a video to demo it working.

Demo video:

Not sure if anyone is following this thread still, but I’ve recently been following Superhouse and doing some home automation research because I will be building a house in the next year. In my research I came across PMMI Lighting ( ). They seem to be doing something very similar to what is talked about in this thread. The have the LED drivers (Meanwell LDD 1000 I think) on a single board in a central location and Cat5/6 out to the lights/switches/motion detectors. All the smarts are in a Raspberry Pi and Arduino Mega. Switches are momentary switches.

I would be curious to hear what others think of this solution.

Looks interesting, though a bunch of it doesn’t look like it would comply with Aus standards and I’m pretty uncertain what does comply for fixed low voltage wiring.

I’ve been toying with using off the shelf AC downlights and adding a i2c controller to them and building a house wide i2c based lighting network (requires range extenders, but pretty doable).

I just checked out their web site. Their system is almost exactly what I am doing in my house except for the low voltage part. Their bulbs must be proprietary as they have no drivers in them, according to what I read. I don’t believe that anyone makes bulbs like that although they do make downlights with separate drivers. The fact that there are no prices listed or dealers is also worrisome. I have yet to see a residential lighting control panel that was not priced like it was gold plated. I think I’ll keep plugging away on my DIY system until someone gets it right at a reasonable price.

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