Low Voltage Whole House Power Supply

[petewill]

After using my low voltage whole house power supply for a couple years I finally made a video about it. It's pretty simple and cheap (assuming you can get a free/recycled computer power supply) but has served me well. I use it to power my blinds, lights, motion sensors, etc. all around my house. It uses a computer power supply and provides me with 12v, 5v and 3.3v DC power. Use this at your own risk and make sure to check out the Voltage Drop Calculator and Wire Gauge Calculator sites to make sure your wires are the correct gauge.

DIY Low Voltage Whole House Power Supply – 09:29
— Pete B

Parts list
Computer Power Supply
Fuse Block
Push-on Terminals
1A Fuses
Wire - 16 Gauge
Ground Bar

[sundberg84]

Awsome @petewill ! I love your videos! Great work!!

[CrankyCoder]

VERY COOL!!!!!

I like this. I am going to be working on some automated curtains here soon, this is an option for powering it definitely!!

[csa02221862]

GREAT! Thanks much. I will be implementing this very soon.

[Lawrence Helm]

Either https://nl.aliexpress.com/item/12V-DC-power-distribution-9-way-PCB-board-terminal-block-for-switching-power-supply-electricity-current/32506638397.html?spm=2114.13010208.99999999.261.EGpgTj or https://nl.aliexpress.com/item/Panel-Mount-10-Position-Power-Distribution-Fuse-Module-Board-For-AC-DC-5-32V/32665224187.html?spm=2114.13010208.99999999.267.EGpgTj looks like a nice solution, going to do something like this my self soon

[petewill]

@Lawrence-Helm
Cool, thanks for sharing. Nice to have other options. I didn't see any info on the wire gauge so just be careful about putting too much current through.

[csa02221862]

There are 2 boards listed the second has the following specs translated from Dutch.

Panel Mount Power Distribution Fuse Module Board.
specification:
Working voltage: AC or DC 5 ~ 32V, total current rating 40Amp.afmetingen: 150mm x 72.5mm x 29mm (W x L x H) .ingangsklemmen: pitch 7.62mm / 0.3 ", current 30A for each position, thread size 26 ~ 10 AWG, stripping length 8mm Metric M3 welded schroef.P1 output terminals: pitch 5.08mm / 0.2 ", 10A maximum current for each position, size 26 ~ 12 AWG wire, strip length 7mm, Metric M2.5 slotted screw .P2-1 to P2-10 output terminals: pitch 7.5mm / 0.295 "maximum current of 10A per position, size 26 ~ 12 AWG wire, strip length 7mm, Metric M2.5 slotted schroef.zekering holders medium Blade ATO / ATC fuse, factory-installed fuses 5Amp. fused fail indication functieFR-4 fiberglass PCB, dual copper layers.

[petewill]

@csa02221862 Nice! I didn't see that. Those specs look good!

[JonnyDev13]

What type of wires did you use for your contact sensors? I will hopefully be building a new house soon I was thinking of putting a separate node for each room or each door/window depending on floorplan, but if I could run all contact sensors to a single node, I think that would simplify it and make it a lot easier to put in place. On that same note, if you know, could you run wires for temperature sensors and PIR motion sensors or anything like that over longer distances similar to your contact sensors?

[petewill]

@JonnyDev13 I use cat5 or cat6 wires for my contact sensors. I also use it for my PIR motion sensors which all go back to one node. I'm not sure of the exact number but I probably have about 25 contact and PIR sensors going to my one node (an Arduino Mega). Temperature is a little trickier and I originally had all my Dallas sensors going back to the one main node I have now spilt them by floor and they are performing much better.
To save space in my conduit I have run separate cat5/6 wires to my attic and I spliced in all the PIR and contact sensors there for my upper floor. As far as distance I believe my longest PIR sensor is about 60 ft or so and I've never had any issues. The Dallas sensors are more like 30 ft and I've limited them to 3 per node.

[JonnyDev13]

@petewill That's great! So do you basically have one ethernet cable going to each room and then split out the different wires within it to wire up the PIR and contact sensors within that room? What was the trouble with the temperature sensors? This page says you should be able to connect many of them to a single arduino pin, but I admit I haven't tried it with more than one.

I assumed this, but maybe it's better to ask. Do your PIR sensors and Temperature sensors get their power from the arduino they're connected to, or do they actually get it directly from your whole house power supply?

[petewill]

@JonnyDev13 said in Low Voltage Whole House Power Supply:

So do you basically have one ethernet cable going to each room

Sort of. I actually have access to almost all of my rooms from the attic so I run the individual stands of cat5 to the sensors that are spliced in to the "main" cat5 line to the basement. I also have a thicker 18 gauge wire running 5v power from the whole house power supply that powers all the sensors. So, it is cat5 for power and "data" to the individual sensors that are connected to the main lines from the basement. Many cat5 cables are connected to the one 18ga power line with wire nuts. Labeling your wires is key here. It can turn into a rats nest fast too. Hopefully that makes sense.

What was the trouble with the temperature sensors?

I'm not sure. It would work for a while (weeks) then all of a sudden they would stop working. I tried various resistors and always powered them from the whole house power supply. I eventually just gave up and rewired them when I put my whole house fan in.

[JonnyDev13]

@petewill Thanks for explaining. That will be helpful if I get to the point where I can try to do something like this!