Nikola Tesla

Nikola Tesla, a Serbian electrical engineer arrived in America in 1884, and he brought with him the solution to Edison’s problem. Tesla was an engineer and mathematician, he understood the science of the electricity including Ohm’s law and Jules law, mathematical descriptions of the relationship between voltage, current, resistance and power. Jules law revealed Edison’s problem, the simple formula, shows that the power lost when current flows in a wire is equal to the resistance of the wire times the current squared. Most of the power loss becomes heat, the wire becomes hot. The conductor was one factor in line loss, but current affected line loss exponentially, reducing current without reducing available power would solve the problem. Edison knew that higher voltages and lower currents would resolve the line loss problem, but high voltages were dangerous, there had already been some deaths when experimenting with this solution. It was not possible to safely deliver electricity at a thousand volts or more into homes. The solution that Tesla ended up proposing, a solution that was rejected by Edison, was to abandon DC, and develop an electrical grid using AC. Unlike DC, AC doesn’t flow constantly in one direction, it changes direction surging back and forth. AC could be easily produced with a special type of generator and has some very interesting properties. The surging back and forth motion of the current produces electromagnetic radiation that can induce current flow in adjacent but unconnected conductors. Tesla understood this radiation and perfected a device capable of changing voltage and current in an electrical system, the transformer. This changed everything, suddenly it was possible to deliver electricity hundreds of kilometers using high voltage low current transmission, below current reduced line losses dramatically. The wires carrying the high voltage were suspended on towers at a safe height. The final step in this solution occurred when a step down transformer converted the electricity back to a less dangerous low voltage with higher current for use in the homes and industries of the community. The relatively short distance from the transformer to the homes meant that line loss from the higher current was minimized, Tesla had found a solution to Edison’s line loss problem.