How does an elevator works ?

The most interesting-and important-aspect of an elevator is it's counterweight that makes it all possible.The counterweight hangs opposite the pulley system and balances the weight of the car in which the passengers ride, plus an additional 40 to 45 percent of the car's weight. An electric motor with a braking system drives an arrangement of cables and pulleys. Nowadays hydraulic systems have replaced the old pulleys.At times, the counterweight is heavier than the car it's lifting-such as when the car has no passengers in it.This arrangement creates excess energy, which dissipates as heat. Recent designs are revamping elevators to harness the power of gravity and divert this energy to a building's electrical grid.