What's that high pitched sound you hear when someone has a TV on?

Question

I don't know if I'm going crazy... But whenever I walk into a classroom where the TV is on or someone turns one of the school's TV's on, I hear this really high-pitched sound. It's quiet, but it still drives me insane when the room is totally silent except for that.

What is that sound??

Answer 1

You have good ears. It is the high frequency pulse of the flyback transformer. That is part of what draws the picture on a picture tube. Older TVs are rely bad that way.

When I was a kid and teen, in the early seventies the large color consoles where very noisy

that way. Specially if you stood close to the back side of the set.

More recent tube TVs are much quieter.

Answer 2

You are probably hearing the horizontal frequency circuit or the flyback transformer.

http://en.wikipedia.org/wiki/Wikipedia:R...