Drinfeld's commutation relations for Y(sl(2)) are recast into a more practi
cal form that coincides with the solution of the RTT relations with tr T(u)
-extension. In terms of this form we present the realizations of a Yangian
in terms of elementary quantum mechanics. It sheds new light on the physica
l meaning of Y(sl(2)). (C) 1998 Published by Elsevier Science B.V.