Power factor calculation - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 11th March 2007, 03:35 PM   #1
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Default Power factor calculation

How to calculate the ratio of resistive and reactive load if the impedance/resistance is not measurable?
http://www.ibiblio.org/kuphaldt/elec...html#02216.png

As a practical example, Id like to measure the cos(phi) of an energy saving light bulb which states to consume 8W but measures 230V * 0.057A = 13.1W.
Of course, believing the manufacturer is the easiest, 13.1W 8W gives a power factor of 0.61 but I'd like to verify.
Out of circuit, the bulb has an infinite resistance probably caused by the internal ignition circuit.

/Hugo
  Reply With Quote
Old 11th March 2007, 03:59 PM   #2
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Said bulbs have a complex supply / ignition circuit.
You cannot derive the power factor from that simple formula.

Only way I know of is a small additional resistor and an oscilloscope.

/sreten.
  Reply With Quote
Old 11th March 2007, 04:30 PM   #3
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Say a 10ohm resistor in series and go from there?

/Hugo
  Reply With Quote
Old 11th March 2007, 05:11 PM   #4
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Yes. With an oscilloscope you can then see the current and
its relationship with input voltage. May not be continuous.

/sreten.
  Reply With Quote
Old 11th March 2007, 05:21 PM   #5
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Thanks.
Would there be a way to compensate these bulbs for a higher power factor. I calculated a 457F (!) capacitor would bring the power factor close to 1. Apart from the fact that its rather silly to do, I'm trying to get a grasp of the basic math.

/Hugo
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Power Factor Correction - PFC with MC34262 luka Power Supplies 19 24th November 2013 02:37 AM
Power factor correction Stefano Pass Labs 3 12th July 2008 01:58 PM
Power Factor correction daly41k Pass Labs 4 30th June 2007 11:28 PM
Power Factor Correction Narcisse91 Power Supplies 16 30th September 2006 04:04 PM
Power Crest Factor ChocoHolic Solid State 15 2nd April 2005 06:46 PM


New To Site? Need Help?

All times are GMT. The time now is 07:51 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2