Measuring impedance of Pot/attenuator - diyAudio
 Measuring impedance of Pot/attenuator
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, 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
 6th January 2011, 06:05 PM #1 diyAudio Member     Join Date: Oct 2010 Location: Denver, Colorado Measuring impedance of Pot/attenuator I have a series attenuator that I traded for many years ago, and I can't remember what the value is. How do you measure the value of a pot or attenuator?
 6th January 2011, 06:13 PM #2 diyAudio Member   Join Date: Nov 2003 Location: Brighton UK Hi, in to ground disregarding the wiper. If switched it may vary. rgds, sreten. That input impedance. Output is wiper to ground with the input near shorted. __________________ There is nothing more practical than a really good theory - Ludwig Boltzmann When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
 6th January 2011, 06:37 PM #3 diyAudio Member     Join Date: Oct 2010 Location: Denver, Colorado It's that easy? The resistance between in 'in' and 'ground' ? Wow, I didn't know it was that simple! Thanks!
 6th January 2011, 06:38 PM #4 diyAudio Member   Join Date: Feb 2010 Location: England Impedence is the measure of reactance and resistance combined and so because there isn't any reactance in a pot your left measuring the resistance! __________________ I thought about it once, but then thought again.
diyAudio Member

Join Date: Oct 2010
Quote:
 Originally Posted by Boscoe Impedence is the measure of reactance and resistance combined and so because there isn't any reactance in a pot your left measuring the resistance!
Aha! That makes sense - I was probably getting hung up on the semantics... a pot is referred to as having a 50K impedance.

 6th January 2011, 09:11 PM #6 diyAudio Member   Join Date: May 2007 In most cases the pot will have its value marked on it somewhere.
diyAudio Member

Join Date: Oct 2010
Quote:
 Originally Posted by DF96 In most cases the pot will have its value marked on it somewhere.
Yes. But the item that I do not know the value is an Attenuator made from a 24 pole switch and a bunch of resistors. Hence why I need to ask!

 7th January 2011, 10:44 AM #8 diyAudio Member   Join Date: May 2007 Ah, now I understand!
 7th January 2011, 10:55 AM #9 diyAudio Member   Join Date: Jul 2004 Location: Scottish Borders Hi, check the resistance from input to common for all switch positions. It may vary. Check also if it is make before break or break before make. A break before make may go open circuit on the output when very slowly operating the switch between positions. A make before break may read a little low on the output, during the switch over between positions. __________________ regards Andrew T. Sent from my desktop computer using a keyboard
diyAudio Member

Join Date: Oct 2010
Quote:
 Originally Posted by AndrewT A break before make may go open circuit on the output when very slowly operating the switch between positions. A make before break may read a little low on the output, during the switch over between positions.
It is a Make Before Break.

I also have a switch in my junk box that is Break Before Make. Other than the obvious clicking that this would have as you move between each pole, are there any other disadvantages to a BBM?

 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 OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post dallaire Multi-Way 4 11th December 2007 10:44 AM ch83575 Multi-Way 4 24th November 2005 08:31 AM Kevinbd Solid State 1 22nd October 2004 07:00 AM gary f Multi-Way 12 5th June 2004 12:18 AM pinkmouse Solid State 5 23rd May 2002 08:15 PM

 New To Site? Need Help?

All times are GMT. The time now is 12:53 PM.

 Home - Contact Us - Advertise - Rules - diyAudio Store - Sponsors - Archive - Privacy Statement - Terms of Service - Top - Opt-out policy

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.