Rabbi Welcher on "Yom Kippur - 9/10/2013" can be downloaded here.
Rabbi Welcher on "Viduy" can be downloaded here.
Rabbi Welcher on "Inuyim of Yom Kippur" can be downloaded here.
Rabbi Welcher on Teshuva on Yom Kippur According to the Rambam and Rabbeinu Yonah can be downloaded here.