Balanced ladder attenuator, make before brake question - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

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
Reply
 
Thread Tools Search this Thread
Old 22nd January 2014, 07:24 PM   #1
2wice is offline 2wice  South Africa
diyAudio Member
 
Join Date: Feb 2013
Location: Pretoria
Default Balanced ladder attenuator, make before brake question

What happens when an attenuator gets stuck on make before brake?
  Reply With Quote
Old 23rd January 2014, 11:57 AM   #2
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
You always get the same volume?
  Reply With Quote
Old 23rd January 2014, 12:06 PM   #3
diyAudio Member
 
Join Date: Feb 2012
Location: Ireland
In theory you end up with the two resistors positions in parallel.
  Reply With Quote
Old 23rd January 2014, 12:31 PM   #4
2wice is offline 2wice  South Africa
diyAudio Member
 
Join Date: Feb 2013
Location: Pretoria
Quote:
Originally Posted by mcandmar View Post
In theory you end up with the two resistors positions in parallel.
Thanks mcandmar,

What would that do to the output, I'm designing an attenuator but cannot guarantee that it will stop exactly on one resistor pad, it's not indented.

It might span 2 pads.
  Reply With Quote
Old 23rd January 2014, 01:27 PM   #5
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
as you sweep through the steps the attenuation will increase as you engage two pads of the adjacent steps and return to normal attenuation when only one pad of the step engages.

You can calculate the attenuation of the two steps and the attenuation of the combined effect of the dual pad step.
__________________
regards Andrew T.
  Reply With Quote
Old 23rd January 2014, 01:39 PM   #6
2wice is offline 2wice  South Africa
diyAudio Member
 
Join Date: Feb 2013
Location: Pretoria
Thanks Andrew

I'll have to try and indent it then.
  Reply With Quote
Old 31st January 2014, 12:06 PM   #7
2wice is offline 2wice  South Africa
diyAudio Member
 
Join Date: Feb 2013
Location: Pretoria
If make-before-brake(m-b-b) increases attenuation even for a moment, would there be a positive outcome if only the signal wiper or ground wiper was m-b-b? And which one would it be? The ground I assume?
  Reply With Quote
Old 31st January 2014, 01:04 PM   #8
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
It is not usual to switch the Signal Return line.

If you want to switch both Signal Flow and Signal Return, then your switch needs twice as many poles.
__________________
regards Andrew T.
  Reply With Quote
Old 31st January 2014, 03:30 PM   #9
2wice is offline 2wice  South Africa
diyAudio Member
 
Join Date: Feb 2013
Location: Pretoria
I'm trying to implement something like the attached.

I have a "wiper" that connects Rin with Rg, by changing the size of the wiper or or pad connected to Rin/Rg or changing the alignment of the pads, I should be able to get Rin or Rg or both to be m-b-b.

My thoughts are that the possible better options would be for both to be m-b-b but for Rg to happen slightly before Rin, or just Rg to be m-b-b.
Attached Images
File Type: gif Balanced ladder type attenuator.gif (33.9 KB, 150 views)
  Reply With Quote
Old 17th February 2014, 07:55 PM   #10
2wice is offline 2wice  South Africa
diyAudio Member
 
Join Date: Feb 2013
Location: Pretoria
I'm tinkering with this design in my head and would like some assistance please.

In the attached, the signal in and ground planes are solid plated copper (1mm). Are there any benefits to doing it like this or is it better to have the signal in and ground out as traces on FR4 in stead of a solid plane? Click the image to open in full size.
  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
brake before make? RS 317-651 Kjeldsen Parts 2 24th October 2012 07:35 AM
HELP with DIY ladder attenuator !!!!! mcgreg66 Parts 1 4th July 2011 12:45 PM
Blanced stereo step attenuator ladder type question! bbakota2000 Parts 11 10th June 2004 07:51 AM
Ladder relay attenuator or so? Eccu Solid State 0 6th October 2003 12:00 PM


New To Site? Need Help?

All times are GMT. The time now is 03:21 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