On Tue, Oct 18, 2011 at 12:15 PM, Stefan Jafs <stefan.j...@gmail.com> wrote: > I guess the big unknown is the PF, I assumed 60% (based on Googeling), the > is a power supply, would it not be higher for a transformer load?
To continue the water analogy, power factor is like a big reserve tank right before the water tap. It can cause your water demand to be out-of-sync with the apparent water usage (coming out of the tap). You run the faucet for a bit, and the tank starts to drain, but the supply pipe isn't touched. Then the tank starts to fill, pulling from the supply pipe. Then you shut the faucet off, but the tank keeps filling. Or so I'm given to understand; the actual mechanism behind power factor is magic to me. I know a purely resistive load -- like a space heater -- has a power factor of 1.0. "Inductive loads" are "reactive", whatever that means. :) Apparently AC motors are "inductive". Rectifiers -- like in an AC->DC power supply, such as in a PC -- are also apparently "reactive". "Power factor correction" helps turn equipment with a lower power factor into something with a higher power factor. The numbers I usually see pulled out of the air for PC power supply units are 0.6 PF for a standard PSU, and 0.9 PF for a PFC PSU. I have no idea how much things vary in practice. -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe ntsysadmin
