I reckon today's computers use constant voltage and current... So the power consumption is constant. But why today's mobos use 3-phase (or more) power supply to stabilize the current... Are there anything wrong with the above statements? Thanks Jack
No way! Modern computers have quite elaborate power management systems. The CPU itself has a wide range of power levels depending on the moment-to-momenf computation demands, plus the rest of the computer has things like hard drives, DVD, etc, whose demands change.
They use switchmode supplies that maintain the *voltage* in the face or changing current needs.
Best regards,
Bob Masta DAQARTA v3.50 Data AcQuisition And Real-Time Analysis
if you draw out a three phase on paper you will see the average is higher and more consistent than single. This is especially useful when you use it to power dc.
Computers use constant voltage and widely varying current just as your house uses constant water pressure and widely varying water flow. Your house has a regulator to maintain water pressure. Your computer has power supplies to stabilize voltage.
Computers don't use 3-phase. Home traditionally use two phase electricity. Computers are powered only from one of those two phases. Power supply output has no phases because it is not AC; it is DC. What exactly is your question?
No. Modern cpus (and doubtless other parts of the PC too) have quite elaborate power management schemes these days.
No they don't. The AC supply is assuredly single phase. There a number of different DC voltage outputs to suit the various differing requirements of the components.
Everything.
Graham
In the USA.
In Europe and many (most?) other places it's single phase to homes.
Graham
Keep in mind that '2 phase' power in American homes is very similar to what you use. We just have a center tap on the 240 to get the 120 times 2.
But, in all my Athlon PCs (and I would bet Intel does it too), it uses a 3 phase converter to make the 50+ amp 1.65 Volt core power supply
GG
Homes in the USA use single phase electricity, at two different voltages. Two phase electricity was phased out (pun intended) about a century ago when three phase power was found to be better, but can still be found powering stepper motors.
Tell me about this '3 phase converter' will you ?
Graham
Hi, Graham. You might want to take a look at this Linear Technology article:
Cheers Chris
Notice this 3PHASE powersupply has a DC input and some 3 phase technology within the pwer supply. When most people discuss American split phase or 50hz Three phase they are talking about the mains distribution and not what some clever engineer has built into the inner workings of a power supply.
John G.
Really,
-- "I\'d rather have a bottle in front of me than a frontal lobotomy" http://webpages.charter.net/jamie_5
I think you have your source count and phase count terminology mixed up.
-- "I\'d rather have a bottle in front of me than a frontal lobotomy" http://webpages.charter.net/jamie_5
He's almost certainly referring to a multi-phase buck converter. That's how the CPU core voltage is normally generated on modern systems.
It was the OP who mentioned 3 phase power on his mobo. He probably read this feature off the side of the box - as I did - which was why I mentioned it. The original post _was_ about computer power, wasn't it?
GG
There can be huge changes in current depending on what is on at the time.
Vista powers down hard drives that havent been used for a while and so reducing by a large amount the current taken.
3 phase PSU's ? Dont you mean multi voltages ? I have seen a PC yet that takes 3000 watts ! Unless it was a multi PC setup.
Many mother boards convert 5 volts to 3.3 and below with multiphase buck converters. This is just 2 or more identical buck converters with their on time phase shifted, so that they don't all draw current or output ripple at the same time.
Here is a data sheet for a multi phase buck converter controller, to give you a better idea what this is about.
-- Regards, John Popelish
And so does old Windows 2000 and XP if you want.
about.http://cache.national.com/ds/LM/LM2639.pdf
I suspect its also to pass EMC regs. Systems have to draw a fairly even current from the mains otheriwse they fail EMC regs.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.