Am I on glue or is this correct...... - diyAudio
Go Back   Home > Forums > Design & Build > Parts

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

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 16th September 2009, 03:28 PM   #1
CxTurbo is offline CxTurbo  Canada
diyAudio Member
 
Join Date: Jul 2009
Location: Ontario
Default Am I on glue or is this correct......

Here goes the stupid question. Just want to be sure before I contact the seller. I bought 120 5% .47R 3W resistors from Mouser and the markings on them are correct from what I can tell (Yellow,Violet,Silver,Gold). The problem is they Ohm out at 3R when I tested them. Is this correct? Am I missing something here because all of the 1/4W resistors I ordered match the stated values.

Be gentle

James
  Reply With Quote
Old 16th September 2009, 03:37 PM   #2
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
James,
I am mostly color blind so I never gave in to trying to figure out the color coding. I would inevitably get it wrong anyway.
Test another resistor with your DMM. One you are sure of the value. Then test your .47R resistors and see what happens. If the first reads correct and you still get 3R on the new ones then I guess you have 3R Guess you could put 6 of them in parallel and you would have your .5R for each side of a Pass power supply
Uriah
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 16th September 2009, 03:47 PM   #3
CxTurbo is offline CxTurbo  Canada
diyAudio Member
 
Join Date: Jul 2009
Location: Ontario
Thanks for the reply. I was afraid that they where wrong..........


James
  Reply With Quote
Old 16th September 2009, 03:54 PM   #4
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
Just went and checked my Pass supply and the series resistors are actually all .47R so if that IS what your 3W were for they wont be low enough.
Uriah
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 16th September 2009, 04:08 PM   #5
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
join them all together in series and measure the resistance of the series combination. Expect 55r to 60r.
Divide by 120 to get an approximate average value for resistance.
You could compare a 56r 1% resistor to allow you to correct for your DMM inaccuracy.

Have you checked what your meter reads when you short your test leads together?

I have found that using a 0.1% tolerance resistor to accurately monitor a CCS and use that CCS to drive a current through low value resistors to be a far better method to check individual resistances (voltage drop / current = resistance). I can match low value resistors 0r1 to 1r0 to better than 0.2% with a little bit of care.
__________________
regards Andrew T.
  Reply With Quote
Old 16th September 2009, 04:19 PM   #6
CxTurbo is offline CxTurbo  Canada
diyAudio Member
 
Join Date: Jul 2009
Location: Ontario
Quote:
Originally Posted by udailey View Post
Just went and checked my Pass supply and the series resistors are actually all .47R so if that IS what your 3W were for they wont be low enough.
Uriah

Yep that is what they are for. I am building 5 Aleph-J X's. I have to call Mouser for an RMA and order a different brand I gather since all 120 look wrong 8(.


James
  Reply With Quote
Old 16th September 2009, 04:36 PM   #7
CxTurbo is offline CxTurbo  Canada
diyAudio Member
 
Join Date: Jul 2009
Location: Ontario
Quote:
Originally Posted by AndrewT View Post
Have you checked what your meter reads when you short your test leads together?
Meter reads at 2.50R with the leads shorted. Is that normal?


James
  Reply With Quote
Old 16th September 2009, 04:39 PM   #8
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
AHA! Andrew saves the day again!
So you have .47R resistors. Its okay
Your meter just has a 2.5R resistance internally or in the leads. Thats kinda high. Both of mine are .2R
You add the 2.5R to all your readings.
Uriah
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 16th September 2009, 04:51 PM   #9
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by udailey View Post
Your meter just has a 2.5R resistance internally or in the leads. Thats kinda high.
buy new test leads.
If that does not reduce the zero ohm reading to below 0r2, then buy a new meter.
__________________
regards Andrew T.
  Reply With Quote
Old 16th September 2009, 05:46 PM   #10
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Quote:
Originally Posted by AndrewT View Post
buy new test leads.
If that does not reduce the zero ohm reading to below 0r2, then buy a new meter.
Doesn't the meter have some kind of adjustment to adjust the R-reading to zero with shorted leads?

jd
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W S Maugham
Check out Linear Audio!
  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
What glue to use feverdog873 Multi-Way 17 5th January 2009 11:46 PM
Gel glue loninappleton Full Range 18 29th December 2007 01:03 AM
What glue to use? wixy Multi-Way 26 6th February 2007 11:49 AM
transistor glue? johndbl123 Solid State 18 27th March 2005 05:37 PM
Glue like (better than ) RTV........ ashok Everything Else 8 5th June 2004 12:40 PM


New To Site? Need Help?

All times are GMT. The time now is 12:33 PM.


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