The effect of the corotation and the quiet time ionospheric dynamo electric fields on the dynamics of energetic electrons and protons (with energies between 50 keV and 1 MeV), inside the inner magnetosphere, is investigated, using the concept of drift paths of constant effective potential. The quiet time ionospheric dynamo electric field is given by an analytic empirical model based on scatter radar observations. The corotation electric field and the Earth's magnetic field are given by analytic expressions corresponding to a centered and an eccentric dipole model. The main conclusion is that the quiet time electric fields cause a diurnal modulation of the electron and proton precipitation. At low L values the locus in longitude of the maximum precipitation is shown to be energy dependent. ¿ The American Geophysical Union 1989