Editing LC circuit (section)

== History ==
The first evidence that a capacitor and inductor could produce electrical oscillations was discovered in 1826 by French scientist [[Felix Savary]].<ref name="Blanchard">{{cite journal
 | last = Blanchard
 | first = Julian
 | title = The History of Electrical Resonance
 | journal = Bell System Technical Journal
 | volume = 20
 | issue = 4
 | pages = 415–433
 | publisher = American Telephone & Telegraph Co.
 | location = U.S.
 | date = October 1941
 | url = https://archive.org/stream/bstj20-4-415#page/n13/mode/2up
 | doi = 10.1002/j.1538-7305.1941.tb03608.x
 | s2cid = 51669988
 | access-date = 2011-03-29}}</ref><ref>{{cite journal
 | last = Savary
 | first = Felix
 | title = Memoirs sur l'Aimentation
 | journal = Annales de Chimie et de Physique
 | volume = 34
 | pages = 5–37
 | publisher = Masson
 | location = Paris
 | year = 1827
 }}</ref> He found that when a [[Leyden jar]] was discharged through a wire wound around an iron needle, sometimes the needle was left magnetized in one direction and sometimes in the opposite direction. He correctly deduced that this was caused by a damped oscillating discharge current in the wire, which reversed the magnetization of the needle back and forth until it was too small to have an effect, leaving the needle magnetized in a random direction. American physicist [[Joseph Henry]] repeated Savary's experiment in 1842 and came to the same conclusion, apparently independently.<ref name="Kimball">{{cite book 
 | last = Kimball
 | first = Arthur Lalanne 
 | title = A College Text-book of Physics
 | edition = 2nd
 | publisher = Henry Hold 
 | year = 1917
 | location = New York
 | pages = [https://archive.org/details/acollegetextboo02kimbgoog/page/n531 516]–517
 | url = https://archive.org/details/acollegetextboo02kimbgoog
 }}</ref><ref name="Huurdeman">{{cite book 
 | last = Huurdeman
 | first = Anton A. 
 | title = The Worldwide History of Telecommunications
 | publisher = Wiley-IEEE
 | year = 2003
 | location = U.S.
 | pages = 199–200
 | url = https://books.google.com/books?id=SnjGRDVIUL4C&pg=PA200
 | isbn = 0-471-20505-2}}</ref>

Irish scientist [[William Thomson, 1st Baron Kelvin|William Thomson]] (Lord Kelvin) in 1853 showed mathematically that the discharge of a Leyden jar through an inductance should be oscillatory, and derived its resonant frequency.<ref name="Blanchard" /><ref name="Kimball" /><ref name="Huurdeman" /> British radio researcher [[Oliver Lodge]], by discharging a large battery of Leyden jars through a long wire, created a tuned circuit with its resonant frequency in the audio range, which produced a musical tone from the spark when it was discharged.<ref name="Kimball" /> In 1857, German physicist [[Berend Wilhelm Feddersen]] photographed the spark produced by a resonant Leyden jar circuit in a rotating mirror, providing visible evidence of the oscillations.<ref name="Blanchard" /><ref name="Kimball" /><ref name="Huurdeman" /> In 1868, Scottish physicist [[James Clerk Maxwell]] calculated the effect of applying an alternating current to a circuit with inductance and capacitance, showing that the response is maximum at the resonant frequency.<ref name="Blanchard" /> The first example of an electrical [[resonance]] curve was published in 1887 by German physicist [[Heinrich Hertz]] in his pioneering paper on the discovery of radio waves, showing the length of spark obtainable from his spark-gap LC resonator detectors as a function of frequency.<ref name="Blanchard" />

One of the first demonstrations of [[resonance]] between tuned circuits was Lodge's "syntonic jars" experiment around 1889.<ref name="Blanchard" /><ref name="Kimball" /> He placed two resonant circuits next to each other, each consisting of a Leyden jar connected to an adjustable one-turn coil with a spark gap. When a high voltage from an induction coil was applied to one tuned circuit, creating sparks and thus oscillating currents, sparks were excited in the other tuned circuit only when the circuits were adjusted to resonance. Lodge and some English scientists preferred the term "''syntony''" for this effect, but the term "''resonance''" eventually stuck.<ref name="Blanchard" /> The first practical use for LC circuits was in the 1890s in [[spark-gap transmitter|spark-gap radio transmitters]] to allow the receiver and transmitter to be tuned to the same frequency. The first patent for a radio system that allowed tuning was filed by Lodge in 1897, although the first practical systems were invented in 1900 by Italian radio pioneer [[Guglielmo Marconi]].<ref name="Blanchard" />