I spent my Saturday modifying my Jaspers rack and as part of that I redid the cable management.
The audio cables are managed in an okay way but the rest is kind of a jungle so I started thinking of a way to make it cleaner.
I have 7 different 12V adapters and another one for 5V.
It’s a lot of wires, and while I could get really short ones for the AC power, the low voltage cables are not removable and I’m stuck with whatever length they have.
There are some threads already on the forum about using a single power supply for powering many devices but they don’t seem to mention using a PC power supply (or I missed it, sorry).
I need 12V and 5V, which are both standard voltages on an ATX power supply.
I need more power on the 12V rail, but most power supplies have the bulk of their power budget on that same line because of GPUs I guess.
I figured I can document my plan and execution here, and post some results afterwards.
Here is my rough plan:
Get a modular PC power supply from a reputable manufacturer
Wire it to turn on when it gets power (this can be done easily by shorting a pin to ground, it’s the same thing that turns it on when it’s installed in a PC)
Create breakout boxes for 12V and 5V, probably with barrel jacks, or with RCA sockets like the Cioks guys do
Make custom length cables, or alternatively make a few different “standard” lengths
One snag could be that I might need different polarities.
I have a few ideas on addressing that:
Use switches (not very idiot proof, unless the switches are recessed, but that makes it hard to DIY)
Hard wire polarity and use color codes (somewhat more idiot proof than switches)
Use physically different connectors on the breakout box (as idiot proof as dealing with individual power bricks)
Use different breakout boxes for each polarity
Use a single breakout box and make different two different cables with swapped polarity
I’m leaning towards the fifth option with some color coding either via the barrel jacks or via the cables. This makes the breakout boxes universal, and if I ever need more cables, I can just make one.
I realize that not everyone might be comfortable with this but I have the skills and tools to do this safely.
Assuming some common sense (like not pouring liquid into the PSU itself, using proper earthing, not sticking nails through the fan grill to poke around and not blocking the fan grill), can you give some examples of the harm you’re thinking of?
The secondary side of those things which are the 12V and 5V lanes are not dangerous for your life but can burn if you short something incorrectly. the primary side of the supply holds high voltage and capacitiors which also do so if the supply is off. this is dangerous for your life. I don´t know exactly what you plan in terms of “shorting a pin to ground” … I don´t say don´t do it. Just making shure you know about electronics, because this could harm you. Seriously.
I see the confusion now. All the high voltage parts are inside the enclosure so I’m personally not worried about those.
Shorting power lines is a legitimate issue that can happen, but every decent power supply has protection against that so I’m not worried about it. I will also check everything with a multimeter to make sure that I didn’t short power rails. On top of that, the way my setup is wired today, I have a main switch that is turned off when I’m not using my music gear so in case there is a short that somehow causes the PSU to fail in a dangerous way, it can realistically only happen when I’m present.
About the part where I’m shorting pin to turn on the PSU, it is a signal line that is meant to be shorted.
Ah ok you are shorting signal pins. I somehow thought you are planning to short something concerning the power switch on the primary side, which made me a little uncomfordable
Hope I don‘t come off the wrong way, don‘t try to be teachy here, it was just about safety.
It’s all good! I just wanted to make sure that I didn’t miss something obvious. It’s good to spell out things related to safety because it might not be obvious to everyone.
If the Cioks DC7 that I have would be able to output more current then this project wouldn’t be needed, but this gave me another idea:
The DC7 is already doing something similar to what I’m planning on doing with the breakout boxes. They have a PSU with fixed polarity and they sell different cables with different lengths and different barrel jacks.
Instead of making my own cables, I might just end up making breakout boxes with RCA jacks that have the same polarity as the Cioks DC7. This would allow me to reuse the cables that I already have, and I would also get a nice color coded system for handling the polarity.
The added bonus is that not every barrel jack is made equal, some have thicker hole in the middle and some have thinner holes. Cioks supports a great variety of barrel jack sizes.
I already have at lest two different types of barrel jacks used by my gear.
I‘m no sparky, so my question might well be very stupid: what about power consumption? I haven‘t bought a PC power supply in the last decade, but I remember them easily going into the 700-800Watt range. Is this a peak value that‘s only reached when drawn by the devices attached or regardless of what‘s connected? As I said, I may have flunked physics class a little too often.
Assuming that nothing went wrong (like an over-voltage situation), a power supply will never push its rated power into a device. It happens the other way. The device pulls power from the power supply and the power supply can provide it within certain limits.
That is where the power rating of a PSU comes into play. It gives you the maximum amount of power that can be given to a consumer.
For a single rail power supply, like a non-fast phone charger, this figure directly gives you the maximum current draw, which is the power divided by the voltage.
A PC power supply has several different power rails, with different voltages, and the overall power rating that you mention is the typically the combination of the capacity of all of these rails.
I did, but I need to power 5 different gadgets that have a steady state consumption of about 1A and probably higher during startup.
I have 2 more that I haven’t measured yet.
That is also a valid option, assuming I can get USB cables that are the right length and won’t melt at 24W. I actually have a few MyVolts Step Up Tips that I could use, which I didn’t consider.
