I know this is illegal but is it dangerous or cunning.

inteificio · 9th January 2006, 09:11 PM

I wish all my posts did not seem melodramatic, but the non dangerous things I do by trial and error!

Ok I have a ground loop problem, some of my nice audio signal trickles through the ground!

After building my first mains filter one of the components gave me an idea. it has an 250v MOV. it has an extremely high resistance upto 250v then it conducts readily. Normally used across live/neutral as a surge protector.

I had an idea, if i get a 12v MOV and put it inline with my earth wire. anything that trickles down the earth below 12v is stopped (like a leaky audio signal) but when i do get a case short the 230v flies on through!

Is there anything I am overlooking?

while I am here can anyone explain what the hell a ground loop actually is, i have had some simple descriptions but nothing else!

thanks for reading

Tube_Dude · 9th January 2006, 09:19 PM

Quote:

Originally posted by Peter Scowcroft

I had an idea, if i get a 12v MOV and put it inline with my earth wire. anything that trickles down the earth below 12v is stopped (like a leaky audio signal) but when i do get a case short the 230v flies on through!

Is there anything I am overlooking?

Hi Peter

And if the MOV fail open , as usually they do ...

pinkmouse · 9th January 2006, 09:19 PM

Peter, please read this.

poobah · 9th January 2006, 09:24 PM

No No -

Grounds amust be solid connections or they serve little purpose.

Grounds are provide for 2 basic reasons; 1) to keep exposed metal/conductors from injurious potentials. 2) to provide a low resistance path for return currents so that circuit breakers or fuses will open.

The resistance of an "active" MOV is NOT so low... nor can it carry the return currents without exploding.

Why do you believe you Have a ground loop? Describe the symptoms and attack the cause. These problems are best solved by more traditional means.

SY · 9th January 2006, 09:27 PM

And keep clear in your head the difference between safety ground (which you NEVER want to interrupt!) and signal ground, which can be lifted.

inteificio · 9th January 2006, 09:55 PM

Hi,

I was just curious about that. no worries I won't try.

Thanks for the link pinky. I have followed your advice from last time. I have bought a pre with XLR connections. That fixes it for the front two channels (where the buzz was BAD) the others are not to much of a prob. the buzz is quiet, and when I have my 5.1 on it is generally VERY noisy so I can;t hear it.

shame, I thought I had thought of something cunning.

9th January 2006, 09:11 PM	#1
inteificio diyAudio Member Join Date: Dec 2004 Location: York	I know this is illegal but is it dangerous or cunning. I wish all my posts did not seem melodramatic, but the non dangerous things I do by trial and error! Ok I have a ground loop problem, some of my nice audio signal trickles through the ground! After building my first mains filter one of the components gave me an idea. it has an 250v MOV. it has an extremely high resistance upto 250v then it conducts readily. Normally used across live/neutral as a surge protector. I had an idea, if i get a 12v MOV and put it inline with my earth wire. anything that trickles down the earth below 12v is stopped (like a leaky audio signal) but when i do get a case short the 230v flies on through! Is there anything I am overlooking? while I am here can anyone explain what the hell a ground loop actually is, i have had some simple descriptions but nothing else! thanks for reading

9th January 2006, 09:19 PM	#3
pinkmouse diyAudio Moderator Join Date: Apr 2002 Location: Chatham, England	Peter, please read this. __________________ Al I conceive of nothing, in religion, science or philosophy, that is more than the proper thing to wear, for a while. Charles Fort

9th January 2006, 09:27 PM	#5
SY diyAudio Moderator Join Date: Oct 2002 Location: Chicagoland Blog Entries: 1	And keep clear in your head the difference between safety ground (which you NEVER want to interrupt!) and signal ground, which can be lifted. __________________ If there's a sucker born every minute, where do the rest of them come from?

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Hemp drivers illegal to sell in U.S.?	G	Full Range	53	24th April 2007 05:49 PM
Kenwood A83 dangerous amp??	hugobross	Solid State	1	5th November 2003 07:38 PM
215 decibel !! Could be dangerous	massive	Everything Else	10	29th August 2003 04:27 PM


	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

9th January 2006, 09:24 PM	#4
poobah diyAudio Member Join Date: Nov 2005	No No - Grounds amust be solid connections or they serve little purpose. Grounds are provide for 2 basic reasons; 1) to keep exposed metal/conductors from injurious potentials. 2) to provide a low resistance path for return currents so that circuit breakers or fuses will open. The resistance of an "active" MOV is NOT so low... nor can it carry the return currents without exploding. Why do you believe you Have a ground loop? Describe the symptoms and attack the cause. These problems are best solved by more traditional means.

9th January 2006, 09:55 PM	#6
inteificio diyAudio Member Join Date: Dec 2004 Location: York	Hi, I was just curious about that. no worries I won't try. Thanks for the link pinky. I have followed your advice from last time. I have bought a pre with XLR connections. That fixes it for the front two channels (where the buzz was BAD) the others are not to much of a prob. the buzz is quiet, and when I have my 5.1 on it is generally VERY noisy so I can;t hear it. shame, I thought I had thought of something cunning.

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read