Dear My friends
in explaining ( Don’t Care Cells in the Karnaugh Map) i am confusing of bicycle example , they want light elimination with the raider increasing his speed and with increasing of speed the voltage , and start from L1 in lower speed , when speed is increased then illumination L1& L2 ....etc until all light L1,L2,L3,L4&L5 illuminating , after that no effect on speed and voltage on light , my question is , why when he start to build digital circuit start from L5 ? and assume all light is ON ?
Logically it must start from L1 and write Boolean equation of Digital circuit , after that L2 and write K-map of it with both L1 and L2 on ,until all light is illuminate in L5 stage
why in example thy start from L5 ?

 

It would be nice if you provided the example are asking us to explain to you. There are many ways to achieve the affect that is being asked for, including some that are not digital at all. In a digital solution you can treat each light as a separate problem independent of the others, or you can piggyback the solution for one onto the solution for others. Part of it depends on how the voltage is being presented to the digital circuit, which you haven't given any indication of. Since we are not mind readers....