I found this, reading this thread:
http://forum.allaboutcircuits.com/showthread.php?t=45641

In this link:
http://forum.allaboutcircuits.com/blog.php?b=378&page=3#comments

Is it a type error or do I not understand?

 

No, it is a typo. Bill might want that to read "slowly turn them on and slowly turn them off".

P.S. For clarity, "typo" is a contraction of "typographical error".

 

Thanks. It'll be fixed on both copies.

That particular article gets a lot of views nowdays, that and I'm a page pusher.