  We study stochastic ratchets with inertia in the limit where the time
correlations become important. We have developed a Fokker-Planck type equation
for the ratchet problem which includes the memory effects. It is tested with
comparison to the Langevin simulations. The effect of the memory in the system
is analyzed extensively. A positive feedback regime which manifests itself as
instabilities is observed. This may be regarded as an illustration of
stochastic resonance.
