Liquid crystals are mostly known for their use in displays, but over the past decade these materials have been applied in a number of other devices such as tunable lenses or beam steering devices. A common technique to realize a gradual electric field profile as is required to obtain a gradual refractive index profile in these applications is the use of weakly conductive materials. The weakly conductive layers are able to spread the voltage profile which is applied through well-conductive electrodes at the side of the weakly conductive layer. The simulation and design of such structures is not trivial because two or three dimensional quasi-static electric field profiles need to be calculated. This is due to the fact that the resistivity of the conductive layers and the dielectric properties of the liquid crystal are coupled. An exact solution requires solving a number of coupled differential equations. In this paper, we develop a model to simulate the RC-effects with an approximate model.