Quickest source would be an article from the Bulletin of the Tomkins Institute entitled "Stress and Tension." I've posted a copy of that paper on our website; click back to the BOL home page, scroll down to the Tomkins Institute URL, then to the link to the Bulletin articles where you'll find what you're looking for.
At the moment, the easiest way to read about affect theory in clear prose and more detail is my 1992 book "Shame and Pride: Affect, Sex, and the Birth of the Self." Cheap paperback. After you've read some of this material, check back with us to let us know what you think about it.