Various examples of differential-difference equations encountered in a
pplications show a rich variety of relaxation properties which, being
important exceptions, do not permit the construction of a general theo
ry. The authors study and give a new interpretation of a relaxation sy
stem which is typical from many points of view and which has been well
known in the theory of quantum oscillators for 60 years. Two theorems
on the existence of relaxation cycles are proved, and then a study of
their stability properties is prepared, as usual, by constructing the
asymptotics of the relaxation oscillations. Bibliography: