Electrical engineering credited with establishing the term "electricity". He also designed the versorium: a device that detects the presence of statically charged objects. In 1762 Swedish professor Johan Carl Wilcke invented a device later named electrophorus that produced a static electric charge. By 1800 Alessandro Volta had developed the voltaic pile, a forerunner of the electric battery In the 19th century, research into the subject started to intensify. Notable developments in this century include the work of Georg Ohm, who in 1827 quantified the relationship between the electric current and potential difference in a conductor, of Michael Faraday (the discoverer of electromagnetic
Battery electric vehicle from 56,000 units in 1998 to over 21 million in 2008, and reaching an estimated 120 million e-bikes on the road in early 2010. China is the world's leading manufacturer of e-bikes, with 22.2 million units produced in 2009. Some of the biggest manufacturers of E-bikes in the world are BYD, Geoby. An increasing variety of personal transporters are being manufactured, including the one-wheeled self-balancing unicycles, self-balancing scooters, electric kick scooters, and electric skateboards. Several battery electric ships operate throughout the world, some for business. Electric ferries are being operated and constructed. The motor controller receives a signal from potentiometers