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The World's Tiniest Power Supply Unit
An anonymous reader writes "This year at CES members of the press got to grab a glimpse of the world's tiniest power supply. Well actually it is the world's tiniest 12V snap-in ATX DC-to-DC power supply, but you get the idea. This unit produces 120W of power and is about the size of two AA batteries. It is specifically designed for use with Mini-ITX motherboards, but can be used in many other applications."
What input range does it take? Is it suitable for automotive use?
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What will that power? My graphics card?
" it will have to be used with an external AC-to-DC power converter"So this is just like all the other mini itx adaptors in that it requires an external brick to provide the juice. Who cares how small the internal part is?
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
>>Very nice, very small, but only converts DC to DC.....
That's the point for many ITX boxes. Devices running on 12 Vdc are wonderful for vehicles. This is a much cleaner solution for the PC in my vehicle.
Yep, I never spell check.
More incorrect spellings can be found he
It takes dc and supplies dc. Doesn't that make it more of a converter?
And if so, it's no big deal. You can buy decent switched cap converters at Digi-key for a couple of bucks. I bought one not too long ago to step 14v down to 5 and supply 4 or so amps, and it was about the same size. The small footprint at 120w is fairly nifty, but otherwise I don't see the big deal.
Weaselmancer
rediculous.
After skimming the datasheet, it's actually a 40 watt "power supply" - The 5V and 3.3V rails can only provide 40 watts combined. The 12V output is just a switched 12 volt input; no regulation is performed on this.
;)
Going by the same logic that these guys use to claim their supply is >100 watts, the 200 watt AT power supply in the linux shitbox by my feet is actually a 1400 watt supply - after all the IEC 120V outlet on the back is rated for 10 amps, yielding a 1.2KW extra output "rail". You might even be able to call this a 2200 watt supply in europe...
The lack of a regulated 12V output makes this PSU useless for in-car PCs. The "12V" seen in a car is anything but that - it varies from 13 to 15 volts DC depending on engine RPM and electrical loads, browns out significantly when you start your car, and can have *huge* transients on it.
Every time a new device comes out, especially consumer electronics like the PSP and iPod I give people the same advice: wait. The early adopters are beta testers. Wait a year or so for people's computers to blow up from this new power supply and then buy your bug-free version for cheaper.
Please note I have never used this power supply before and have no idea how well it's made. I'm just making a general statement on electronics.
Isn't this just a passthrough at this point? If you have to have an external AC->DC converter, then why not just stick the how PSU outside the box...
The gates in my computer are AND, OR and NOT; they are not Bill.
No, you weren't wrong, just slightly narrow in scope on your definition of a power supply. The purpose of a power supply is take an input power and provide clean output power in the form of AC or DC at one or more voltage levels to an end device. In the case of standard computer supplies that means transforming the 120V AC power coming in (AC being a far more efficient means a long distance power transmission) to a stable 12v/5V/3.3V/-5V DC output for use by the local electronic components.
A typical switching power supply accomplishes this by: a) Run the 120VAC thru a transformer, down to ~24VAC
b) Rectifying the output with diodes, filter with bulk capacitors to ~24VDC.
c) "Chop" the DC voltage into several subvoltages by turning a transistor feeding a buck coil on/off at high frequency (~10kHz).
d) Filter the resulting subvoltages with bulk and fine capacitors, resulting in a smooth clean output.
Skips step "a" (and "b"), making it convient to run off an available 12V source (say your car outlet). Telco DC power supplies have long done the same thing off ~48V DC power.
That being said... Despite the apparent enthusiasm, I have a very hard time believing the claim that this is possibly a 120W power supply for 3 distinct reasons:
1) If you take the specifications at face value, at full power this would being drawing 10.4 amps (claimed 96% eff.) in the 12V input. Given that the input wires appear to be 18AWG (standard ATX wire gauge), the wires would be cooking at that amperage. Typical transmission current ratings for 18AWG stranded copper is 2.3 amps.
2) The power connection appears to be a standard phono jack, again not suitable for 10 amps.
3) I only see 2 coils, 2 capacitors, a handful of diodes, possibly an inductor, and the chopper ciruits are most likely ICs sandwiched between the boards, in the pictures. That means there are only 2 buck transformer circuits, one taking 12V to 5V and one taking 12V to 3.3V, leaving 12V output unfiltered (highly noisy do to switching) and the 5/3.3V very rough under any significant power draw.
Therefore, given the above... I can;t see this power supply realistically providing more than ~30W at best, being very noisy while doing it....
This device is not suitable for cars. The specs state that it requires 12VDC in to operate - it's not uncommon for a vehicle to run at 13.8VDC, and there are of course issues with power spikes from the ignition system.
There are some 12V PSU's outthere (either morex or cubid from memory) that use the 12VDC supply rail and pass it straight through to the motherboards 12VDC rail. Stick some spikes down that line and you could zap something important.
If you want to power a computer in a vehicle, then the best stuff I have seen is from Opus Solutions who make excellent PSU's for in-vehicle use. They support a wide input voltage range, have automatic low power shutdown, and can be configured to start the computer when the car has been running for a set delay, and shutdown the computer when the ignition has been switched off for a certain amount of time.
Highly recommended.