All About Circuits Forum  

Go Back   All About Circuits Forum > Electronics Forums > General Electronics Chat


General Electronics Chat Discussion forum for general chat about anything electronics related, including asking questions about material in the All About Circuits E-book, Worksheets, and Videos.

Reply   Post New Thread
Thread Tools Display Modes
Old 01-19-2010, 11:19 AM
iulian28ti's Avatar
iulian28ti iulian28ti is offline
Junior Member
Join Date: Dec 2009
Posts: 42
Default Power Factor in DC

Well, basically what i'm interested in is active FPC.

But first i have a few questions.

First about power line resistance.

Basically, if you have a linear load, and that load is equal to the line resistance (yeah, big big big load, i know, but it's just an abstract example), then we will have a power factor of 0.5 ? In other words, does the line resistance contribute to power factor loss ?

Or is power factor an issue only in AC lines driving a capacitive or inductive
load ?

And finally, i did a bit of reading on active PFC, but i don't understand how exactly can a boost converter help increase PFC. So how ?

Any input is appreciated
Reply With Quote
Old 01-19-2010, 12:35 PM
iulian28ti's Avatar
iulian28ti iulian28ti is offline
Junior Member
Join Date: Dec 2009
Posts: 42

Well, meanwhile i did a bit more reading and from what i can understand , PFC is more about stabilizing input power . Am i right ?
Reply With Quote
Old 01-19-2010, 02:09 PM
Papabravo's Avatar
Papabravo Papabravo is offline
Senior Member
Join Date: Feb 2006
Location: Michigan, USA (GMT-5)
Posts: 5,780

In a DC circuit there are no reactive components. The current and voltage are always in phase, which is another way of saying that the phase difference between the current and voltage is zero degress, and the cosine of zero is one. I know this is hard but remember -- In a DC circuit the power factor is always one, just one, and never anything but one.

In an AC circuit, depending on the components the power factor can take the same values as the cosine of the phase angle between the current and votage waveforms. That reange would be from zero to one.
We never have time to do it right,
But we always have time to do it over.
Reply With Quote
Reply   Post New Thread


Related Site Pages
Section Title
Worksheet Basic AC-DC power supplies
Textbook Tesla polyphase induction motors : Ac Motors
Worksheet AC power
Worksheet Advanced electromagnetism and electromagnetic induction
Textbook AC instrumentation transducers : Ac Metering Circuits
Textbook Three-phase Y and Delta configurations : Polyphase Ac Circuits
Textbook Power in resistive and reactive AC circuits : Power Factor
Textbook Calculating power factor : Power Factor
Textbook Three-phase power systems : Polyphase Ac Circuits
Textbook Measurements of AC magnitude : Basic Ac Theory

Similar Threads
Thread Thread Starter Forum Replies Last Post
Repairing Switched Mode Power Supplies (SMPS) GS3 General Electronics Chat 8 08-08-2012 01:54 PM
Multiple Devices on a Single Power Supply DanRilley General Electronics Chat 6 01-18-2010 04:14 PM
Power Peltier Device from Laptop Power Supply justin_ca The Projects Forum 5 10-04-2009 10:23 AM
Recommend a good quality large DC power supply fastwalker General Electronics Chat 3 08-19-2009 02:29 AM
dc POWER SUPPLY PROBLEM alpha_tayyab General Electronics Chat 7 07-15-2009 05:51 PM

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 04:32 PM.

User-posted content, unless source quoted, is licensed under a Creative Commons Public Domain License.
Powered by vBulletin
Copyright ©2000 - 2014, vBulletin Solutions, Inc.