Stop feedback from capacitors into power... - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 4th December 2010, 11:10 PM   #21
diyAudio Member
 
Join Date: Sep 2010
Location: Chapel Hill, NC
Quote:
Originally Posted by paulb View Post
The reason this thread is unproductive is because what you are asking for doesn't make any sense.
Agree completely.

If you are having problems with a ground loop, use an isolation transformer.

If you don't want to do that use a battery to power your system.

Maybe you should look into your local building code, and see if your landlords are in violation of renting a property that doesn't meet code. The fines will eventually make them fix the wiring where you live.

Other than that you could always move.
  Reply With Quote
Old 4th December 2010, 11:52 PM   #22
godfrey is offline godfrey  South Africa
diyAudio Member
 
Join Date: Nov 2009
Location: Cape Town
Some things to bear in mind:

a) Mains wiring does not have a "positive".
b) Filter capacitors do not have a "positive".
c) AC filters are not "digital".
d) You can't change the frequency of the mains with a filter.
e) Fiddling with mains wiring can be extremely dangerous, especially if you don't know what you're doing.
  Reply With Quote
Old 5th December 2010, 12:16 AM   #23
diyAudio Member
 
Join Date: Nov 2005
If you attenuate a signal and then feed it back onto itself it disappears...

Makes a lot of sense to me.
  Reply With Quote
Old 5th December 2010, 12:39 AM   #24
diyAudio Member
 
Join Date: Nov 2005
Quote:
Originally Posted by godfrey View Post
Some things to bear in mind:

a) Mains wiring does not have a "positive".
b) Filter capacitors do not have a "positive".
c) AC filters are not "digital".
d) You can't change the frequency of the mains with a filter.
e) Fiddling with mains wiring can be extremely dangerous, especially if you don't know what you're doing.
Ok so maybe I am not concise but...

A) Mains wiring line is for all intensive purposes in thinking about this circuit, a positive because it is the attractor in this case due to the fact that the other two, neutral and ground, are the supplies.

B) Filter capacitors are non-polar. They do however have one side connected to line and one to neutral. I am obviously referring to one or the other.

C) AC filtration on neutral to ground primarily, and perhaps only, seems to have a positive affect on digital equipment. It is a filter for digital equipment.

D) Good now I know for sure.

E) If it was not dangerous would it not be worth doing at all . Besides I have no fear of the dangerous of AC. I have been making stuff for years, dealt with plenty of wiring etc... but clearly as my posts indicate I am not versed in some of the deeper information of electronics nor am I an electrician so terminology can be off.
  Reply With Quote
Old 5th December 2010, 12:41 AM   #25
diyAudio Member
 
Join Date: Nov 2005
Oh and ******* drop the landlord thing. I know more about it then you do because I am living with it and take the benefit of the doubt that I have assessed the situation or I would be asking about changing it.
  Reply With Quote
Old 5th December 2010, 12:58 AM   #26
diyAudio Member
 
Join Date: Sep 2010
Location: Chapel Hill, NC
Quote:
Originally Posted by Destroyer OS. View Post
If you attenuate a signal and then feed it back onto itself it disappears...

Makes a lot of sense to me.
What is the signal you want to attenuate and feed back onto itself?

If it's noise introduced into your system from a ground loop in your electrical wiring, the way they are dealt with is to get the electrical wiring redone properly, use an isolation transformer, or run off of a battery.

If there is a cheaper way to solve a ground loop from power lines that is as easy to use as the three that have been mentioned multiple times already I'd love to know since I haven't seen them in any instrumentation book I've ever read.
  Reply With Quote
Old 5th December 2010, 03:47 AM   #27
diyAudio Member
 
Join Date: Nov 2005
I solved the ground loop by eliminating the earth ground in my power conditioner box.

Inside my amp there is a starground that connects to chassis, so all is as safe as can be without earth. I would not have even the barely working earth ground if it was not for me upgrading the sockets in my apartment so what can you do... I lost a bit of filtration and safety wise I do not get as much comfort. If I can figure out how to overcome the resistance of the earth ground I can add that filtration back in, but currently it seems like a losing battle in my mind so I will think about it another time.

I am trying to find a good editor for making a drawing.

Basically how it would work.


1. Diodes in front of both phase inverters to prevent cancellation pre-capacitors.

2. Phase inverter in parallel with bypass.

3. The bypass's and phase inverters at each end of the capacitors connect to line and neutral.

That is exactly what I want to make now. The capacitors attenuate noise off of the mains, the phase inverters cancel the noise altogether so nothing running in series in your house can experience any of the noise and re-introduction is impossible. The capacitors act like a crossover capacitor for speakers; they only allow certain frequencies through. The only potential flaw could be a loud diode but I could just buy some fancy ones for a few bucks instead of 30 cents.
  Reply With Quote
Old 5th December 2010, 03:57 AM   #28
diyAudio Member
 
Join Date: Sep 2010
Location: Melbourne
Inverting a noise signal: first you need a sample of the signal, if you insist on using capacitors you need at least 2 in series and it is easier with 3, you need the appropriate resistive load to get the required phase shift at the specified frequency. You need a small isolation transformer to remove any common mode from the signal, then you need an adjustable attenuator and a mixer to mix it with the appropriate amplifier input.

And to top it off it will only work at one frequency, mains noise contains more than one frequency and it will need adjusting every time the noise level changes. If the noise phase changes due to load changes in the building it fails. Using a DSP phase shift with the appropriate parameters will work better.

So much for a simple solution that is why as smgidcumb mentions instrumentation books do not mention solutions like this and your problem is very common in the instrumentation field, think low level signals in an industrial environment.
  Reply With Quote
Old 5th December 2010, 04:13 AM   #29
diyAudio Member
 
Join Date: Nov 2005
Yes that is very complicated. I do imagine there is a solution of real time phase inversion but it is far beyond me.

Overall the filtration in my unit is still phenomenal. I am looking for ways to improve it, especially if I ever sell any more units.
  Reply With Quote
Old 5th December 2010, 04:22 AM   #30
diyAudio Member
 
Join Date: Nov 2005
Now I am led back to the idea of burning off the frequencies somehow.

Basically I need something that draws electrons indiscriminately with disregard to frequency, in order to supply the frequency demands of the circuit. If that is possible.

Last edited by Destroyer OS.; 5th December 2010 at 04:41 AM.
  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
Exactness of feedback capacitors? bigwill Tubes / Valves 14 7th May 2009 11:41 AM
hitachi capacitors? feedback please jarthel Parts 0 15th June 2007 12:05 AM
feedback on panasonic pureism and x-pro capacitors jarthel Parts 1 3rd May 2007 11:18 AM
how important are feedback capacitors to prevent oscillation in active crossover? mazurek Parts 8 22nd January 2006 07:19 PM
power capacitors tuben Solid State 5 20th July 2004 12:16 PM


New To Site? Need Help?

All times are GMT. The time now is 09:25 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