This project uses only two components can be used to adjust the brightness of a standard incandescent bulb. In a bedroom or living room, it allows us to choose between maximum power and reduced power for ambient lighting.
The circuit shown in Figure 1 only works only with incandescent bulbs, it should not be used with fluorescent lamps or electronic.
One advantage of this circuit is that in the less powerful position have reduced consumption for the lamp, which falls somewhere around 50%.
The assembly can be done by taking advantage of it can be installed where there is a switch in the wall, which will be replaced with a double switch, as shown in Figure 2.
The diode is mounted on the own switch that controls the lighting level, and while the other serves to turn on and turn off the lamp.
The diode 1 is indicated, which means that lamps up to 100 W can be controlled in the 110 V line and twice the 220 V line, for 1 x 220 V = 220 W.
We recommend 1N4004 to the line of 110 V and 1N4007 for the line of 220 V. It will not be necessary to observe the polarity of this component in the assembly.
D1 - 1N4004 or 1N4007 - see text
S1, S2 - SPST switches (on-off)