What's that green dot?

Subject: What's that green dot?

Date: Wed Sep 20 00:07:51 2000
Posted by John Stechschulte
Grade level: 10-12 School: Upper Arlington High School
City: Columbus State/Province: OH Country: USA
Area of science: Engineering
ID: 969422871.Eg

Message:


In many old TV sets, if they were turned on then off again quickly, a 
small, mainly green (but also other colors) dot was left in the center of 
the screen.  This seems to not be a problem in newer sets (I haven't seen 
it in years), and I seem to remember thinking that it was somehow bad for 
the TV to leave it like this (maybe urban legend).  Is there still some 
sort of electron flow from the electron gun to the cathode?  Why did it 
only occur when the TV was turned off right after it was turned on?

Re: What's that green dot?

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