Fog Creek Software
Discussion Board




Power brick rant

Another peripheral, another freaking power brick. Why do I have fifteen different transformers under my desk?

Okay, I want someone, somewhere to fix this. USB was supposed to carry power for peripherals, but I guess it was too hard. Well now that USB2 and Firewire are established you guys can go back and put power back on the pins. I also want daisy-chaining put back in the spec.

And if nobody can bother doing that, then I want a standard low-voltage power established with a standard connector. Everyone can use 15v or 7.5v with three-pin connectors (+7.5v, -7.5v, and ground. You want 15v? Take it from the high and low pins).

Then Belkin & Co can produce a desktop power brick with a dozen low-voltage power couplings (LVPC) that you can plug everything into. You can also put LVPC's in peripherals (monitors, switches, KVM's, keyboards).

This brick thing is just plain insane.

Philo

Philo
Sunday, January 18, 2004

I agree.  For years I've been expecting a low-voltage DC standard to appear for home and office outlets.  I can't believe we don't have one yet.  Seems like you could have a few nice little jacks right near the AC jacks.  Sure would be nice anyway.  Do any engineers out there have any electrical reasons why these bricks have not yet been eliminated?  And it would be best if they could be rigged to draw almost no power when not in use.

Between network devices and printers and speaker amps and peripheral hubs and chargers and telephones and external drives, I think I have something on the order of 15 DC converters in my home office, and maybe another half dozen at work.  (But now seeing it written way makes it sound like a rather bourgious complaint.  Ugh.)

At least some of the manufacturers have started shrinking theirs.  PowerMac and iPod chargers are small.  My Siemens cellphone charger is miniscule.

veal
Sunday, January 18, 2004

Why not just redesign the PC power supply so that it accepts external DC connections (using some sort of standardized connector, like Philo suggests)? 

I remember one very nice feature on older Macs -- you could plug the monitor power cable directly into the desktop's power supply.  (Don't know if current Macs still support this.)  That way, the monitor would automatically power up when you turned on the Mac, and power down when you turned it off.  It was a good energy-conservation feature in the days before EnergyStar, plus it reduced cable clutter.

Robert Jacobson
Sunday, January 18, 2004

PCs used to do that as well - at least, the ones I used to build did. I wonder why they don't anymore? I haven't seen that on a PSU for years. I imagine it's because the PSU these days are usually rated somewhere up to about 450w for most desktop machines, and with increased power usage by processors and gfx cards, they just aren't high enough rated to run some monster 23" monitor as well.

Andrew Cherry
Sunday, January 18, 2004

Power consumption is the reason, yes. Modern CPUs (especially dual CPUs), GPUs, multiple hard drives, multiple media drives (CD/DVD)... it adds up pretty fast.

Of course, every LCD monitor I have is an ultra-low power usage DC-based power (yet more bricks... at least they're the inline kind of bricks). Seems to me that someone could be put back onto the PC for low powered displays like LCDs.

Brad Wilson (dotnetguy.techieswithcats.com)
Sunday, January 18, 2004

As an aside, I got a ViewSonic VP171s LCD -- it's in ViewSonic's line of "professional" (expensive) monitors.  The picture is beautiful, but in addition, it doesn't require a brick.  It just uses a standard PC power cord, and has the AC/DC converter built into the back of the monitor.

One brick down, 12 to go... ;-)

Ryan
Sunday, January 18, 2004

My cheapo viewsonic has a brick, but it's one of those that takes a standard power cable to the outlet, so it won't waste strip space.

I've found that this sort of design is becomig much more popular, though it is still a minority.

Mike Swieton
Sunday, January 18, 2004

I don't understand why the transformer can't be inside the damn monitor.

Philo

Philo
Sunday, January 18, 2004

One thing that really annoys me, got an ipaq last week and it needs a brick plugged into the wall as well as the plug into the USB cable - both cables run into an adapter that goes directly into the base of the ipaq.

I wondered, if there is 5V running through the USB cable, and the power cord is simply being piggy backed into the same socket on the device, why couldn't HP provide a cable that would charge and synch through the USB cable rather than the 2 cable configuration? - And then I found that Belkin makes a cable that does exactly that, why does HP not use this style of cable by default - surely it would reduce manufacturing costs?

The only downside I could see is that using only 5V instead of the 12V that a wall plug transformer would provide, so it would probably take longer to recharge - and then I looked at the specs on the wall brick - it only outputs 5V anyway!

Chris Ormerod
Sunday, January 18, 2004

One reason for external power bricks is because of the differences in power between US and Europe.  We're 110V at 60Hz, while Europe is at 220V at 50Hz.  By using an external adapter, you don't have to build a dual-format power converter, which can save several dollars on the cost of a device, and you can ship the same main unit to both regions.

Ben Combee
Sunday, January 18, 2004

Regarding monitors, most or all CRTs have transformers inside of the case, so they just need a simple power cable to connect the monitor to an AC outlet.  AFAIK, plugging a CRT into a PC power supply (like in the good old days) wouldn't put much additional strain on the power supply itself.  In that situation, the power supply is just acting as a pass-through for the AC, rather than converting the monitor's power to DC.  (I'm not an electrical engineering type of guy, so please correct me if I'm wrong.)  On the other hand, since CRTs seem to be on the way out, it's probably a moot point.

For other peripherals, it still seems more efficient, in theory, to have a beefed-up power supply that handles all of the power switching.  Sure, you might need an 800 watt or 1000 watt power supply to handle everything, but it would still probably be simpler and cheaper in the long run than having a separate power brick for every peripheral.

Robert Jacobson
Sunday, January 18, 2004

"on older Macs -- you could plug the monitor power cable directly into the desktop's power supply.  (Don't know if current Macs still support this)"

Robert,

On current Macs there is a single cable running from CPU to monitor. The cable is about 1/4" in diameter and it carries the video signals, the power for the monitor, and a connection to the USB hub that is integrated in the monitor. The power switch for the CPU is located as a glowing patch on the monitor itself. There are no moving parts to this - the finger brushes across it and it detects the resistance change in the monitor body. The keyboard plugs into the monitor and the mouse plugs into the keyboard, leaving an addtional 2 USB ports for other devices like cameras or speakers. Of course there are also USB ports on the back of the CPU and those don't get used up. With my Mac system, everything except the printer runs of the CPU. My APC power conditioner has only two things plugged into it right now and I've got a full range of peripherals. There are no wall warts in this room.

Ed the Millwright
Sunday, January 18, 2004

"One reason for external power bricks is because of the differences in power between US and Europe.  We're 110V at 60Hz, while Europe is at 220V at 50Hz.  By using an external adapter, you don't have to build a dual-format power converter, which can save several dollars on the cost of a device, and you can ship the same main unit to both regions."

For God's sake! My electric shaver takes dual voltage systems and you cannot include that in computers that are much more expensive than a shaver?

uncronopio
Sunday, January 18, 2004

'scuze me while I whip this 18 foot power strip out.  I agree the bricks are a pain.  I agree on your USB assessment too.  Just the other day I bought a USB hub for my father.  I looked at three.  Two of them needed to be plugged into electricity.  WTF, I bought the one that didn't.  Why would I want another brick?

Mike
Sunday, January 18, 2004

The problem, unfortunately, is that using an un-powered hub may lead to being unable to plug some devices into it, because they take too much power for themselves.

Brad Wilson (dotnetguy.techieswithcats.com)
Monday, January 19, 2004

Thanks for the details, Ed.  Obviously Apple knows how to do it right.

Robert Jacobson
Monday, January 19, 2004

It's a bitch, no doubt.  The Apple ADC connector does do power for the LCD via the desktop system. 

If they have to use power bricks, couldn't they give them a standard, stackable form factor?

H. Lally Singh
Monday, January 19, 2004

We can use bluetooth or whatnot for wireless comms.

But what we really need is wireless power!

Don't laugh; RFID for example does just this..

i like i
Monday, January 19, 2004

I think RFID has devices on trickle load until they get the wakeup call.  Generally broadcast regulations mean you can't broadcast microwave  with sufficient power to get a chip up so they have a battery.

Simon Lucy
Monday, January 19, 2004

RFID wouldn't happen to be the technology behind the toll pass stuck to my windscreen would it? Every morning on my way to work it beeps as I pass the toll plaza, but they gave me no instructions to install fresh batteries - so I assume there is some sort of wireless energy going on there (there is no solar panel or anything like that)

Chris Ormerod
Monday, January 19, 2004

Yup, two types of RFID -- "active" (needs a battery/power source) and "passive" (the most common type, which gets its power from from the "reader" (antenna.))

http://www.aimglobal.org/technologies/rfid/what_is_rfid.asp

Robert Jacobson
Monday, January 19, 2004

"I don't understand why the transformer can't be inside the damn monitor"

The same reason so many transformers suc kpower even when the thing they are attached to do not require it. Cost.

Have you tried putting something with a transformer in it on top of your monitor and watching the pretty effects? I'm sure some shielding could sort it out, but it would cost more.


Monday, January 19, 2004

Uh, I was talking LCD's - not affected by magnetic fields.

CRT's generally *do* have the transformer inside them.

Philo

Philo
Monday, January 19, 2004

There's a bunch of stuff at stake here:
1) Often times, engineers plan on the individual properties of the brick while designing the component, to save part count.  So it's a 9v power supply that really only puts out the 9v needed while you are drawing 500mA from it.
2) USB only provides 5v with a certain amount of amperage.  So the user can easily overload a USB bus and cause problems that require a tech support call.  DC/DC converters are available, but they haven't been really good for very long and they may end up being more expensive than just going with the brick.
3) Bricks are very very cheap compared to any other sort of power supply, even closed-frame power supplies to be integrated.  They are also already UL approved and require no design work.  Stocking several different bricks is probably cheaper for small stuff than a multi-voltage integral power supply because you are talking about a linear, not a switching, power supply.
4) Because of the wide variety of bricks (AC or DC, ranging from 100mA to 1 Amp, voltages between 3.3 and 15, potentially multiple different voltages, regulated or not regulated, grounded/polarized, etc.) manufacturers have been forced to design their parts with confusing and incompatable plugs to prevent people from screwing things up.  It's a standardziation nightmare.
5) It looks sleaker because the pictures don't include the brick.
6) Heating and interference issues are less troublesome with that outside of the box.
7) "That's the way we've always done things!"

Just about all of the electronics that I build end up using a brick.  It's cheap and easy.  There's a lot of momentum there.

Flamebait Sr.
Wednesday, January 21, 2004

Oh, and Philo-the-dough-boy, taking +7.5 and -7.5 to get 15v is very bad for safety and reliability.  If components fail, it can burn out a power supply.  It also means that if anything gets grounded anywhere, there will be electricity flowing.

Furthermore, DC outlets and their wiring is a whole new and annoying issue.  You lose a lot of current per inch of wire compared to 120v AC.

Flamebait Sr.
Wednesday, January 21, 2004

Oh, not to flood the area with posts, passive RFID devices are build to use microamps of power.  Not even enough to light up a single LED.  It doesn't scale well, at least, without being about as smart as sticking your hand in an operating microwave.

Flamebait Sr.
Wednesday, January 21, 2004

Flamebait, don't know if you're still here, but I'd move your #7 reason to #1. Engineers are a bizarre mix of innovators and reactionaries. I'm sure if you'd tried to talk an engineer into USB in the early 80's they'd have laughed at you - "EVERY device on the same four wires? You're insane."

Putting power on USB is simply another design restriction. If we can't have that, then standardizing on a specific power supply is *definitely* simply another design restriction.

And as for the "we use different plugs so you can't plug the wrong power supply in" - that's mostly true. Actually I'd buy "we use different plugs so you can't plug a *damaging* power supply in." and I'll bet it was a UL requirement, not a design spec. The easiest solution would be to label the required power on teh device - which seems to be a vanishing art.

Philo

Philo
Sunday, January 25, 2004

*  Recent Topics

*  Fog Creek Home