Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Power Resistor Distortion
Power Resistor Distortion
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 7th May 2017, 11:46 PM   #11
Conrad Hoffman is offline Conrad Hoffman  United States
diyAudio Member
 
Join Date: Mar 2007
Location: Canandaigua, NY USA
Elvee, my hat is off to you! I put a large U-shaped magnet up to the resistor body and the THD dropped to 1/3 it's previous value. Looking at the residual on the scope, the overall shape didn't change much, just the dramatic amplitude drop. My regular load resistors are immune to this. So the problem appears to be magnetic
__________________
I may be barking up the wrong tree, but at least I'm barking!
  Reply With Quote
Old 8th May 2017, 12:20 AM   #12
Max Headroom is offline Max Headroom  Australia
diyAudio Member
 
Max Headroom's Avatar
 
Join Date: Jan 2013
Location: West Australia, near to the beach, natural ambient sounds mostly.
Motor action between the send and return windings ?, some mechanical compliance of the fixing material ?.
Some speaker cables with compliant insulation exhibit distortion because of this.

Dan.
  Reply With Quote
Old 17th September 2019, 01:13 AM   #13
davidsrsb is offline davidsrsb  Malaysia
diyAudio Member
 
Join Date: Dec 2005
Location: Kuala Lumpur
There is very little published on nichrome permeability. If it is magnetic, it probably has a hysteresis loop.
I doubt motor effects as the resistor would vibrate audibly
  Reply With Quote
Old 27th September 2019, 04:29 PM   #14
opcom is offline opcom  United States
diyAudio Member
 
opcom's Avatar
 
Join Date: May 2008
Location: Texas
This industrial applications reference handbook concerns resistance wire of many alloys.
Please see first the table of "General Information on Metals and Alloys"


Alloy Handbook of Electrical Resistance - Wilbur B Driver Co. (incl. lavish illustrations section, 255MB PDF) Why not?

Alloy Handbook of Electrical Resistance - Wilbur B Driver Co. (sans the lavish illustrations section, 54MB PDF)

The book is old but these materials are still available albeit the trade names for some of them have changed. There may also be competitors' data books but this is what was found and what was scanned

Hope this helps!
  Reply With Quote
Old 27th September 2019, 10:05 PM   #15
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
Magnetic resistance wire? Probably cheap steel or the wrong kind of stainless, no wonder it distorts measurably. Wirewound or metal film resistors should have basically unmeasurable distortion (when the right metal is used!).


Magnetic wire would have poor properties at radio frequencies too.



Nichrome wire is non-magnetic BTW - that dummy load probably had steel terminals rather than brass - same issue as steel speaker terminals.
  Reply With Quote

Reply


Power Resistor DistortionHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Resistor Distortion Measurement SyncTronX Parts 60 6th March 2017 09:13 PM
Industry Standard resistor distortion test? DualTriode Solid State 6 2nd February 2016 03:35 PM
Looking for Article on Resistor Distortion Samuel Groner Parts 2 18th March 2013 02:16 PM
Resistor distortion Art M Parts 5 13th December 2010 01:30 PM
K50 lm1875 feedback resistor distortion waz664 Chip Amps 7 3rd October 2007 07:21 AM


New To Site? Need Help?

All times are GMT. The time now is 10:13 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki