Sensibly Powering DC Technology?

splatnet asks: "Having upgraded my PC to a Mac Mini all my IT kit is now DC. The Mini, my flatscreen, external USB HDD, USB DVD writer, JBL speakers, ADSL/Wireless Router. I have practically the same amount of space taken up for transformers as I do computer equipment! Has anyone found/invented a way to power multiple DC devices (all with slightly different power requirements)? I'm thinking in terms of space/convenience/running costs etc." It would be neat if there was a DC power source that could be tuned to a specific voltage, as well as modular plugs to fit your various devices. Is there anything out there that comes close?

Comments

Sticky tape and elmers

[TristanBrotherton]

1) Take power bricks and place in pile. 2) Cover in duct tape. 3) Continue wrapping of duck tape over cables. 4) Spray paint blue. Voila, a uni power brick... Seriously, i have this problem too, its even worse for traveling with devices. Most of the time the power brick is bigger than the gadget. I ended up building my powerbricks into my table, (underneath the desk) looks neater. Not much more functional. -tris me

Dupe

[Game Genie]

This has been discussed before. That being said, good luck. Having read the last discussion, I think you'll need it.

Yes

[infernalC]

Your typical PC AT power supply comes very close. It outputs 12V and 5V DC (most of what you need) and can handle a lot of current if it isn't a cheapo. Go to Radio Shack, get some plugs and some solder and have fun.

You're asking for Trouble!

[ka9dgx]

You've got all sorts of equipment, with all sorts of hidden assumptions about what ground means. In the best case scenario, you actually have no weird assumptions, or nasty surges when devices get turned on, and it all works.

I've learned, the hard way, that the coaxial power plugs used on most devices these days will temporarily SHORT when you plug them it, which means, at a minimum, a separate current limited regulator for each plug.

Accept the things you cannot change, this is one of them.

--Mike--

Requirements

[justanyone]

The requirements seem to be:

* 5 output ports;
* for each port (or via a central control panel) configuration for output voltage on that port, continuously variable from 2 VDC to 24 VDC;
* each port capable of 50 watts without significant voltage drop;
* a handful of accessory connectors / converters including 1 plug male -> 4 plugs female, big diameter plug to small plug, extension cables, etc.
* silent power supply if possible / air cooled, or very, very quiet fan

I'd think that a sealed design with a large external heat sink is best. I have a cat and the cat hair ends up all over things on the floor, which is the power bricks and one of my PC's, making cleaning a regular (once / 2 months) thing to lengthen lifespan / prevent overheating).

I don't care about weight too much. It should be well grounded.

Another wonderful idea is the ability of it to use as input a 12VDC car/marine-deep-cycle battery, so if the power goes, I can still use my accessories.

Guitarists might have some ideas

[Mr_Dyqik]

Lots of guitarists use something similar to power multiple FX pedals on stage. However FX pedals tend to be fairly low power, and all at simialr voltages (as they mostly run on 9V square batteries).

Contact someone who puts together racks of FX for guitarists/stage musicians?

Re:Guitarists might have some ideas

[iainl]

The big ol' line of effects pedals all run at 9VDC, and you can even get nice little runs of cable to link them in parallel to the one transformer.

Which is bugger all use for this situation, where everything wants its own different voltage, unfortunately.

Re:Guitarists might have some ideas

[marcelmouse]

Well, this hypothetical device is the holy grail of electronic musicians. There are no guitarists in my band, but there's a fair number of stompboxes and other electronics distributed among 5 people. If they were all manufactured by (if we were sponsored by!!!) Boss, then everything would be running at 9V DC, as specified immediately above. However, our stuff varies as much as the original Ask/.er, so there's just NO HOPE. My bass microsynth runs at 15V DC. The Handsonic pulls an amp at 12V. Only about 1/3 of our devices share a voltage, and it's a real shame, because no 1 person has 2 9V DC boxes. Therefore, a concentrated power solution doesn't really work. So, we wind up making do with little velcro strips and gaff tape.

Somewhere, I saw an interview with the sound/tech guy for one of those bands that is a vaguely electronic pop/rock band. (It wasn't Radiohead, but it was some similar band.) They had a whole 9U rack devoted to a power solution for the whole band. It had a power conditioner in it, as well as a serious UPS. It provided clean power for the whole band, across a whole range of DC voltages, in different amperages, as well as AC. I priced out JUST those parts that were commercially available, not even counting the homebrew stuff, and it worked out to be something like fifteen hundred dollars.

So, the answer to your Ask Slashdot?

"Get rich & famous, then hire somebody else to tame your cables."

Re:I'm waiting for the day

[Gilk180]

>Any other requirements could be done by stepping voltage down.h

You can't just step down DC power, that is one of the many reasons AC is ubiquitous when most electronics operate on DC.

• With AC, voltages can be stepped down or up.
  
• AC can be more easily transmitted over longer distances because it is transmitted at very high voltage(and therefore low current), then transformed near the destination to 110/220/whatever you might use.
  
• AC can easily be converted into DC. Give me a good diode. Or even better, 4 diodes and a capacitor. The inverse it not true.
  
• I know I'm forgetting some things...
  

Solar enthusiasts

[ferralis]

If someone comes up with a workable solution, there are probably any number of solar power enthusiasts who would pay $$$ for a working product that would allow them to wire a circuit their house with DC of a fixed voltage which could then be converted for each device. Wall warts (and many other transformers) leak current due to their design (and usually also to their generally cheap components). This is a parasitic load- it does nothing for you and is using power even when the wall wart is disconnected. So, those of you who have the right background and ideas, consider this: A single, ultra-high efficiency transformer that generates,say, a clean 24 VDC with a stable ground. Low resistance (say 10-gauge?) wiring throughout the house with special outlets. Universal adapters (similar to RV or Car adapters) that plug in to these special outlets, then into the appliance. These could be quite small, because there would be no need for a lossy/bulky step-down transformer. Something to think about, anyway...

Ham Radio suppliers carry these power supplies.

[sakusha]

Check a ham radio supplier, any decent shop will carry many different power supply units that are designed to address this precise problem.
For example, I googled and the first entry under "ham radio supplies" was aesham.com, their catalog is downloadable as a PDF. On page 82, they have power supplies from Astron, Daiwa, Diamond, AIM, etc. Most of them only output a single voltage but are adjustable, however a few units have multiple voltage outputs. Many of these units have big geeky analog gauges on the front indicating the power draw, for extra nerd appeal.
A few pages later (pg 84) they have power distribution busses, for feeding multiple units from the same voltage. Just what you're looking for. And Hams are totally obsessed with clean power, so you can set up rigs with pure, clean power and no grounding problems.
Check out some other Amateur Radio suppliers and gaze through the catalogs, and stand in awe at true hardware geeks that have been doing this for about 3 times as long as computers have even existed. I learned more about electronics from Ham Radio catalogs than anywhere else.