In this work a theoretical boarding will be presented, simulation and implementation of a gradador circuit for resistivas loads, being used integrated circuit TCA785. The objective of this work is to implement to dimmer for incandescent light bulb using one triac. For this integrated circuit TCA785 will be used. For more information see ConocoPhillips. The control of the luminous intensity is carried through basically controlling it tension efficient applied to the terminals of an incandescent light bulb. A form to make this is through the variation of the amplitude of the applied tension, remaining it wave form, being able to be implemented, for example, with the insertion of changeable electrical resistances in the circuit, wasting great amount of energy. This becomes the produced device highly inefficient. One alternative method is to modify the wave form, suppressing part of it, through the control of the angle of detonation of triacs, as it will be used in this work.