The Trinity in Two Minutes [1] from Desiring God [2] on Vimeo [3].
Piper perfectly summarizes Edwards conception of the Trinity in two minutes here [4] and that is difficult to do! I think Edwards is correct and if so, it explains why we don’t see the Holy Spirit mentioned sometimes (often?) when the Bible speaks of the Father and the Son. The Spirit may be expressed there in other words.
If you’re interested in reading Edward original thoughts on this to see if Piper is accurate, I did some formatting on Edwards unpublished paper on the Trinity in 2002. It is posted here [5].