Hartley oscillator

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Image:Hartley osc.png

The Hartley oscillator is an LC electronic oscillator that derives its feedback from a tapped coil in parallel with a capacitor (the tank circuit). A Hartley oscillator is therefore a type of inductively coupled variable frequency oscillator. It was invented by Ralph Hartley, who filed for a patent on June 1, 1915 and was awarded patent number 1,356,763 on October 26, 1920.

Hartley oscillators may be series or shunt fed.

Contents

Structure

  • One tapped inductor (or a two-winding transformer)
  • One tuning capacitor

Advantages

  • Frequency varied using a variable capacitor
  • Output amplitude remains constant over the frequency range
  • Feedback ratio of tapped inductor remains constant

Disadvantages

  • Harmonic-rich content
  • Not suitable for a pure sine wave

See also

External links, references, and resources

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