Hartley oscillator


Hartley oscillator

The Hartley oscillator is an LC electronic oscillator that derives its feedback from a tapped coil in parallel with a capacitor (the "tank circuit"). Although there is no requirement for there to be mutual coupling between the two coil segments, the circuit is usually implemented as such. A Hartley oscillator is essentially any configuration that uses a pair of series-connected coils and a single capacitor (see Colpitts oscillator for the equivalent oscillator using "two" capacitors and "one" coil). It was invented by Ralph Hartley, who filed for a patent on June 1, 1915 and was awarded patent number [http://patimg2.uspto.gov/.piw?Docid=01356763&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPALL%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsrchnum.htm%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D1,356,763.PN.%2526OS%3DPN%2F1,356,763%2526RS%3DPN%2F1,356,763&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page] 1,356,763 on October 26, 1920.

Operation

Hartley oscillators may be series or shunt fed.A Hartley oscillator is made up of the following:

* Two inductors which need not be mutual (may be a two-winding transformer)
* One tuning capacitor

Advantages of the Hartley oscillator include:

* The frequency is varied using a variable capacitor
* The output amplitude remains constant over the frequency range
* The feedback ratio of the tapped inductor remains constant

Disadvantages include:

* Harmonic-rich content of the output
* It is not suitable for a pure sine wave

Applications

The Hartley oscillator was extensively used on all broadcast bands including the FM 88-108MHz band. An example is given of the Scott 310E RF oscillator for its FM section.

History

The Hartley oscillator was invented by Ralph V.L. Hartley while he was working for the Research Laboratory of the Western Electric Company. Hartley invented the design while overseeing Bell System's transatlantic radiotelephone tests of 1915. In 1946 Hartley was awarded the IRE medal of honor "For his early work on oscillating circuits employing triode tubes and likewise for his early recognition and clear exposition of the fundamental relationship between the total amount of information which may be transmitted over a transmission system of limited band-width and the time required." [Ralph V. L. Hartley, Legacies, IEEE History Center, updated January 23 2003, [http://www.ieee.org/organizations/history_center/legacies/hartley.html] ] (The second half of the citation refers to Hartley's work in information theory which largely paralleled Harry Nyquist.)

See also

* Armstrong oscillator
* Colpitts oscillator
* Clapp oscillator
* Vačkář oscillator
* Opto-Electronic Oscillator

References

* Radiotron Designer's Handbook, 4th edition

External links

* [http://www.tpub.com/content/neets/14181/css/14181_81.htm Hartley oscillator] , Integrated Publishing


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Hartley — may refer to:Places;England *In Cumbria **Hartley, Cumbria (village) **Hartley Castle *In Devon **Hartley, Plymouth (see Places in Plymouth) *In Kent **Hartley, Kent **Hartley, Cranbrook *In Northumberland **New Hartley **Hartley, Northumberland… …   Wikipedia

  • Hartley-Schaltung — Eine elektrische Dreipunkt Oszillatorschaltung, bei der zwei Induktivitäten und ein Kondensator einen Parallelschwingkreis bilden, wird als Hartley Schaltung oder Hartley Oszillator bezeichnet. Sie ist nach Ralph Hartley benannt, der 1920 ein… …   Deutsch Wikipedia

  • Hartley, Ralph V.L. — SUBJECT AREA: Broadcasting, Electronics and information technology, Telecommunications [br] b. 1889 USA d. 1 May 1970 Summit, New Jersey, USA [br] American engineer who made contributions to radio communications. [br] Hartley obtained his BA in… …   Biographical history of technology

  • Colpitts oscillator — Early schematic of a Colpitts circuit, using a vacuum tube, redrawn from the patent publication. A Colpitts oscillator, invented in 1920 by American engineer Edwin H. Colpitts, is one of a number of designs for electron …   Wikipedia

  • Ralph Hartley — Infobox Scientist name = Ralph Hartley caption = birth date = birth date|1888|11|30 birth place = Spruce, Nevada death date = death date and age|1970|5|1|1888|11|30 death place = New Jersey residence = United States nationality = American field …   Wikipedia

  • Electronic oscillator — An electronic oscillator is an electronic circuit that produces a repetitive electronic signal, often a sine wave or a square wave.A low frequency oscillator (LFO) is an electronic oscillator that generates an AC waveform between 0.1 Hz and 10 Hz …   Wikipedia

  • Clapp oscillator — The Clapp oscillator is one of several types of electronic oscillator constructed from a transistor (or vacuum tube) and a positive feedback network, using the combination of an inductance (L) with a capacitor (C) for frequency determination,… …   Wikipedia

  • Armstrong oscillator — The Armstrong oscillator (also known as Meissner oscillator) is named after the electrical engineer Edwin Armstrong, its inventor. It is sometimes called a tickler oscillator because the feedback needed to produce oscillations is provided using a …   Wikipedia

  • Tesla's oscillator — is a mechanical oscillator conceived of and invented by Nikola Tesla in 1898. It is also referred to as the Earthquake Machine. The machine which Tesla tested was small, around seven inches long, and weighing only one or two pounds; something you …   Wikipedia

  • Scientific phenomena named after people — This is a list of scientific phenomena and concepts named after people (eponymous phenomena). For other lists of eponyms, see eponym. NOTOC A* Abderhalden ninhydrin reaction Emil Abderhalden * Abney effect, Abney s law of additivity William de… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.