The work of Voltare and Ampere laid the foundations of Electrodynamics upon which modern electronics is most definately founded.
The timeline..
The first light switch was invented [1884] employing a "quick-break technology" to prevent arching and was invented by the British engineer John Henry Holmes in Newcastle upon Tyne. Many inventors added to this design see wiki.
The first sealed electromechanical relay was invented in 1835 by the US scientist Joseph Henry building on the work of the British engineer William Sturgeon [1825 - electromagnet]. Onward development of Henry's work in U.S.S.R created a magnetic switch [invented in 1922] in a glass vial by the Russian Professor V. Kovalenkov and became what is known as the Reed Switch [refined 16 years later by Bell Telephone Laboratories [1938]].
How to resources
If authorised the suite of folders offer a comprehensive set of information and items to enable the effective use.
