"Jasen Betts" bravely wrote to "MIKE ROSS" (09 Sep 03  19:15:04)
 --- on the heady topic of "VEHICLE LED'S"


 JB> 05-Sep-03 23:00:50, MIKE ROSS wrote to Greg Mayman

 MR> I forget what this clicking effect is called. You can also hear it
 MR> with an electric guitar going through a fuzz box. When the strings
 MR> are gently moved one can hear that magnetic clicking effect.

 JB> that'd be the clipping in the amplifier in the fuzz box...
 JB> fuzz effect is a heavily clipped signal.

No, it isn't clipping in the amplifier (besides clipping is supposed to
occur in the fuzz box and not in the amplifier). No, the effect I'm
speaking of is a real phenomenon with the discoverer's name given to it.
I'm just drawing a blank at the moment. Oh, ya, just got a brain flash!

Barkhausen Effect - A succession of abrupt changes which occur when the
                    magnetizing force acting on a piece of iron or
                    other magnetic material is varied.

Like I was saying if one amplifies the audio signal a whole lot one can
actually hear tiny clicking sounds as we very slowly and gently disturb
a magnetic field. Have you never experimented the Barkhausen Effect?

I read someplace the clicks are caused by the magnetic lines of force
rearranging themselves across different domains of the magnetic
material. As you know a magnetic material isn't uniform but is formed of
little islands of magnetism called domains which roughly follow the
crystal arrangement of a metal's atoms.

Hope I made your day! 

 Mike
 ****

... You may be a tech if you're entertained by a 6-pack and sparking HV.
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