This is just a fact-finding mission at this point, as I need to work out feasibility before I commit to working on the rest of the concept. The basic idea is to try and power up to 8 low-power ITX boards with a single power supply. Each board can be individually powered on or off. After doing some research, I found that simply trying to daisy-chain 24-pin ATX connectors is not going to be ideal, so I figured that the safest way would be for each motherboard to have its own PicoPSU, and the collective PicoPSUs powered by a single ATX unit and therefore a single socket to the wall. To further stability, it may be best to have two ATX units, powering four PicoPSUs each, instead of one powering eight as well as any further devices (drives, fans etc). It would mean two plugs to the wall, but it's better than having eight. In order to do this, the idea in my head is to modify a standard ATX unit (with the correct wattage of course). Remove the usual 24-pin and Molex bunches and replace them with a series of female 12V DC connectors. These would then be connected to the PicoPSUs with male-to-male 12V DC cables. Ambitious I know, but has anyone pulled this off before?
Why use an ATX PSU why not a 12V switching PSU off of eBay? Cheaper for the power as you don't need all the other voltages?
Correct me if I'm missing something here, but why can't you get a mutli plug extender and plug 8 pico psus into that?
Or, alternatively, could run the PicoPSUs from a stable 12v supply of a high enough current. I see where you're coming from though - it'd be cost effective to get a decent ATX PSU and therefore convenient! What power Pico supplies are you looking to run?
That sounds feasible, though I also plan on running a network switch, along with a shared storage array, network optical drive, cooling and possibly a master unit that regulates the whole lot.... and a touch screen. That's pretty much what I'm trying to fabricate, but in a neater package within a specific form factor. Should this build actually take off, and a prototype is created, then I would like this to be a self contained unit, with as little clutter as possible. To be honest, that's where I've not done my homework. Those units appear to come in a 160W variant, but haven't been able to find anything larger. I may be able to find something that isn't a 'PicoPSU', but still small enough (in the form of a PCB) to not take up too much room. Applications of the individual boards themselves would include office/school workstation, file/media server, game server, portable web/database server, possibly even a render farm if networked. I can't imagine them needing to be high-powered boards, and therefore high output PSUs, unless anyone thinks otherwise of course. I'll see if I can make an image that hopefully explains what I'm thinking of.
Basically something like this (excuse the crudeness): The additional two ports per PSU allows for additional components to be connected, such as a network switch and fans etc.
Your probably better off with something like this as ATX power supplies tend not to like running without a load on 3.3v & 5v rails. Also will have less cable mess, etc.
It might actually be the best solution, but looking at those pictures, I'm curious as to how this would connect to the PicoPSUs via a 12v DC lead.
Wires from the wall are screwed into the three screw terminals and all of the positive wires from the 12v DC lead is connected to the big red knob, and all of the negative wires to the big black knob. Though I would recommend finding something that would allow you to plug in an actual plug in the switcher instead of having to splice some wire onto screw terminals. It's safer with the plug versus screw terminals.
Agreed. To be honest I'm looking for something where the exterior facing side of the unit uses the traditional kettle style lead. That's why an ATX PSU would be better. That said. I could get one of these units and wire in a kettle plug socket, along with the appropriate DC jacks. Would still require modding, but far less extensive than breaking up an ATX unit. The design I have in mind allows for either 8 low power ITX boards via PicoPSU, or 4 higher powered ITX boards with graphics cards etc, each with an ATX PSU connected with the usual 24-pin. Because of this, the chassis will allow for up to four ATX units to be installed, but the default configuration of 8 boards would only use up two PSU bays. So in theory, you could have say 2 high powered boards with two ATX PSUs, and 4 low powered boards with a single 12V DC PSU, all running at the same time. In short, if there is a way I can get a DC switching PSU in the shell of an ATX unit, that would be ideal.
Well - you could scrap the internals of a crap ATX unit and place a switching AC-DC (highway to hell?) board in there, with a series of trailing barrel jacks hanging out of the wire output, or as you suggested, a load of barrel sockets in the ATX casing. I'm just wracking my brains as to where might be a good place to source a decent 12V supply...
This is pretty much what I want to do. Like a normal ATX PSU, the unit should be standalone with cables plugging into it. So on the outside there would be a kettle plug socket and main switch. On the other side (which is inside the computer), there would be 6 12v DC jacks, each one labeled to correspond to each motherboard 'bay', and an additional two for other devices such as network switch and cooling gear. Where to find something that allows me to do pretty much that, and output the correct amount of power, is going to be tricky... and a full rig would need two of them!
I've been thinking about things that use a high-power 12V supply. So far, I've come up with Laptops (could caniballise a laptop supply, but might be 15V), battery chargers (also higher than 12v but could be a go-er). Hang on a minute - what about a car battery charger? That'd have a decent transformer/switching in it, perhaps?
To be honest, as long as I am able to find something like dark_avenger suggested (this one), but small enough to fit into an ATX housing and capable of providing the power, I should be fine.
That'd do brilliantly. That's the sort of thing I was thinking of (like a lab power supply) but was thinking a) cost or b) availability. Might be worth looking at Farnell/CPC?
