Abstract
The results of our study of the eclipsing binary systems AF LMi, CzeV188 and CRTS J073333.0+302556 based on new CCD B, V, RC, IC complete light curves, are here presented. The short periods of these systems are confirmed and revised. The light curves were modeled using the latest version of the WilsonDevinney code and, as a result, we found that AF LMi (G3+G9) and CzeV188 (K0+K1) are W UMa-type contact binary systems belonging to the W subclass, showing a shallow degree of fill-out with components in good thermal contact. CRTS J073333.0+302556 is a detached binary system composed by a late dwarf (K8) and an M6 dwarf spectral type components. The asymmetries of the light curves were accounted for with a spot on the surface of one of the component. The absolute elements of the three objects were estimated.
