DC Power distribution - Nix the Transformers?

MailtoDelete asks: "I have most of my electronic gear plugged into a couple power strips hanging off a UPS. Most of these devices have big block-type transformers which, besides being bulky, are a bit of an eyesore. I have been trying to find a product out there somewhere that would allow me to have one central transformer that would distribute DC power at variable voltages, depending on what devices I wish to plug into it (think one AC input and 9 or so DC outputs individually adjustable). I found this device that resembles what I have in mind, but it does not have sufficient output for my router, switches, and various other devices. Is there a product on the market already that would do this? Can I build one with my marginally above average soldering and electrical schematic skills? Have any of you found a better way to eliminate these blocky plug-hogs?"

Comments

Hardware Wars

[Jeremiah Cornelius]

"This is Reddy Kilowatt, reporting a dangerous, overloaded octopus connection in sector five!"

Re:Hardware Wars

[thegrassyknowl]

Wasn't it Thomas Edison who tried to prove that Tesla's 3 phase AC power distribution was dangerous by electrocuting frogs with it and showing how they thrash about vioilently before they died?

*tongue firmly in cheek*
Perhaps DC power distribution is the best after all.

That said, you could easily build a device to power all those said gizmos. You'd really need a quite large multi-tap transformer with appropriate ratings, and a set of voltage regulators for the various voltages... 5, 6, 9, 12, 13.8, possibly a couple of adjustable ones for those pesky items that insist on odd voltages.

I had a similar (homebuilt) device with 6 outputs, all individually regulated.

This is a good excuse for a PIC-type project to set the ouput for each port... It could adjust the regulator to get the right voltage and also toggle relays for each port to get the right transformer tap (so as to avoid dissipating too much energy in the little regulators) for any given voltage.

Re:Hardware Wars

[snorklewacker]

Wasn't it Thomas Edison who tried to prove that Tesla's 3 phase AC power distribution was dangerous by electrocuting frogs with it and showing how they thrash about vioilently before they died?

Not Tesla, Westinghouse. The whole frog twitching thing was a sideshow trick when electricity was first discovered, and could be done with DC. Edison went all the way up to electrocuting horses, and advertised it could be done on people with "Westinghouse's Electric Chair". He thought people would be horrified. In the last bit of irony, several states loved it and actually ordered these things, using them for capital punishment for many decades afterward.

Edison may have been quite an inventor, but he was rather a ruthless man not above gross distortions and character assassination.

Re:Hardware Wars

[alienw]

He was as much an inventor as Bill Gates is a programmer. Above all, he was a businessman. Most of "his" inventions were actually created by the people working for him.

Why?

[Guspaz]

Why bother? If each device has it's own power brick, it's safer. If one fails, the others won't.

If you combine all of them into a single point of failure, you might reduce what you think is an "eye sore" but at the cost of a higher risk of failure.

Is making your setup less sturdy worth a cosmetic fix?

Re:Why?

[voisine]

Good point. I've had atx power supplies fail in spectacular fasion. Scared the crap out of me. I bought a used one and the local computer junk store, plugged it in, turned around, and then *KABLAM*. It was loud enough to make my ears ring. Then thick black acrid smoke started pouring out the back. I took it apart to investigate what the hell happened. It was a fairly large blown capacitor. I had no idea those could explode like that until after this little episode.

Re:Liberator

[Tintivilus]

I'm actually kinda partial to Dr. Ferd's Wart Remover. It's only two-wire (how many grounded wall warts do you have?) and it has a nice big box on the outlet end so you can use a pad of double-sticky mounting tape to hold the mess together.

In places where I have a bunch of wall-warts hanging around, I like to use a Furman Pluglock power strip to keep then together and strapped down. I broke down and bought a couple of these when I got sick of having random things come unplugged in the pile of crap under/behind my desk, and they turned out to be a great buy. They're built like tanks, too.

Re:No.

[harrkev]

What the parent poster said! I design boards for a living (along with doing some VHDL stuff in FPGAs). My expertise is digital, but I do have an Electrical Engineering degree -- and I could not properly design a switching power supply -- at least that what what I was told by my power supply guy after I tried laying out his circuit on the board.

I have also tried my own experiments in this area. I had an old Celeron 466 system, and my scanner, speakers, and force-feedback joystick all ran off of 12V. So I hooked up my computer's 12V rail to some connectors on the back (with caps attached to help reduce noise). Here were the results:

1) Scanner - worked like a charm. But you had to plug in the power while the computer was off. Otherwise, the whole computer would reset iself. This was my one success.

2) Speakers - Worked, but you could hear the hard drive heads moving. The amount of noise was too much, so I had to go back to a separate wall-wart.

3) Force Feedback Joystick - This was a Microsoft model, which connected to the Game port (not a USB model). Apparently, this stick did not like sharing its power ground with its signal ground. The computer shut off instantly, and the joystick was fried. This goes to show that you need to have FLOATING power supplies in any scheme like this.

In the end, my grand experiment was not really worth it, as I spend a couple of hours soldering and drilling, and all I did was to remove one power supply.

But if somebody DID make a power supply box that had the following: 3x12V, 2x9V, 2x6V, 3x5V, all at 2A each, and they could do it for under $100, then I would be very tempted to buy one. Unfortunately, I suspect that this type of supply would go for a lot mroe than $100.