What is Galvanic Coupling?

[iamakda]

Dear all,

Could any one define me what is Galvanic Coupling ?

Thanks.

[selldoor]

Re: What is Galvanic Coupling?

Here is a definition of a galvanic couple

Also called galvanic couple two dissimilar metals or alloys in electrical contact that when immersed in an electrolyte act as the electrodes of an electrolytic cell.

Perhaps if you gave the context of the term?

[iamakda]

Re: What is Galvanic Coupling?

Here is a definition of a galvanic couple

Also called galvanic couple two dissimilar metals or alloys in electrical contact that when immersed in an electrolyte act as the electrodes of an electrolytic cell.

Perhaps if you gave the context of the term?

Hi Selldoor,
I have read this defination but couldnt get anything out of it.

i asked it in context of EMI noise. Noise created by the galvanic coupling between a component and another metal.

Thanks.

[Jack Crow]

Re: What is Galvanic Coupling?

Hi there,
I call this condition a Bi Metallic.
It's been the bane of my existence as a techie.

Not all metals get along well when pressed together and exposed to oxygen.

More than once I have dealt with radios that 'went deaf' due to the metals used in pre selectors.

A classic case was a Mostar radio. The pre selector had huge loss in it.

Took it apart, cleaned the metal on the cover, and on the cavities, plus a steel gasket, then re assembled.
Suddenly the radio started to work.

Had many units that started to work again when the screws are tightened because of oxidized surfaces.

It's a slow process, often taking years to get to the fail point.

Electronics materials tend to react with oxygen. Aluminum, copper, solder, all suffer in oxygen.

Most recently we had a bunch of products go bad due to bad soldering. RHOS chips that were old before they got used.
Did not take to standard solder.
The joints looked good, but the actual contact patch was sub standard.
The different solder chemistry did not work together.
Another form of bi metallic.

Give it a think.

Jack Crow aka Radio Mike
Herndon Virginia

[budm]

Re: What is Galvanic Coupling?

Or you may be talking about coupling or Isolation between two circuits:
http://www.datatranslation.com/resou.../isolation.asp
http://www.avagotech.com/pages/en/optocouplers_plastic/

[iamakda]

Re: What is Galvanic Coupling?

Or you may be talking about coupling or Isolation between two circuits:
http://www.datatranslation.com/resou.../isolation.asp
http://www.avagotech.com/pages/en/optocouplers_plastic/

Dear budm,

I am talking about galvanic coupling and not isolation