Also known as a wireless power transmission, the basic definition of wireless energy transfer is a process that takes place in any type of system in which electrical current is conveyed from a power source to an electrical load. What makes this process unique is that there is no usage of any type of wiring to connect the system to a source of power. While many people tend to associated wireless one and two-way communications like radio signals or cell phone transmissions to the process of wireless energy transfer, this is not correct. Wireless energy transfer has to do supplying operational power to a system that needs to function when connection via electrical wiring or cable is unavailable or inefficient.
The history of wireless energy transfer is often traced back to the early part of the 19th century. William Sturgeon developed the first electromagnet in 1825, which cleared the way for the discovery of the basic principle of electromagnetic induction in 1831. Within just a few years, Nicholas Joseph Callan made use of these two scientific developments to successfully demonstrate that the receipt and transmission of electrical energy could take place without the presence of any type of wiring to connect the points of origin and termination. This was accomplished by using two insulated coils that were placed on opposite sides of a small amount of iron ore. A battery was used to initiate a charge on one coil, which in turn was able to jump to the second coil without benefit of any type of connection.
While the demonstration of the reality of a wireless transfer of energy was a significant event for scientific research, practical applications never quite lived up to early expectations. Part of the reason for this has been suspicion, largely unsubstantiated that the transference of energy using wireless methods was not practical over long distances, and in fact might not even be safe. While experimentation in the early 20th century established successful usage over distances that were roughly the length of the average front yard, many people noted that the presence of any type of obstacles would seriously weaken the quality of the transmission.
Thus, the use of wireless energy transfer has tended to remain with applications that required only very short distances between the transmitter and the receiver. Still, thoughts about the potential for health issues developing due to the bombardment of wireless energy transfer still remain uppermost in the minds of many people, which probably inhibits interest in developing any wide range applications today.
