The Clapp oscillator is one of several types of electronic oscillator constructed from a transistor (or vacuum tube) and a positive feedback network. It was invented by James K. Clapp in 1948. An electronic oscillator is an electronic circuit that produces a repetitive electronic signal, often a sine wave or a square wave. ... Assorted transistors A transistor is a semiconductor device that uses a small amount of voltage or electrical current to control a larger change in voltage or current. ... In electronics, a vacuum tube or (outside North America) thermionic valve or just valve, is a device generally used to amplify, switch or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ... Imbibers of alcoholic drinks the unknown strange organisms were called yeast and they were the starting point of the image. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Referring the notional circuit in the figure, the network is comprised of a single inductor and three capacitors, with two capacitors (C1 and C2) forming a voltage divider that determines the amount of feedback voltage applied to the transistor input. The Clapp oscillator is a Colpitts oscillator with an additional capacitor placed in series with the inductor. The oscillation frequency in hertz (cycles per second) for the circuit in the figure, which uses a field-effect transistor (FET), is A Colpitts oscillator, named after its inventor Edwin H. Colpitts, is one of a number of designs for electronic oscillator circuits. ... Large power N-channel field effect transistor The field-effect transistor (FET) is a transistor that relies on an electric field to control the shape and hence the conductivity of a channel in a semiconductor material. ...

Clapp Oscillator (direct-current biasing network not shown)

A Clapp circuit is often preferred over a Colpitts circuit for constructing a variable frequency oscillator (VFO) that uses a single variable capacitor to adjust the frequency. In a Colpitts VFO, the voltage divider contains the variable capacitor (either C1 or C2). This causes the feedback voltage to be variable as well, sometimes making the Colpitts circuit less likely to achieve oscillation over a portion of the desired frequency range. This problem is avoided in the Clapp circuit by using fixed capacitors in the voltage divider and a variable capacitor (C0) in series with the inductor. Image File history File links I made this. ... VFO is an acronym for Variable Frequency Oscillator. ... VFO is an acronym for Variable Frequency Oscillator. ...

See also

• Armstrong oscillator
• Colpitts oscillator
• Hartley oscillator
• Vackář oscillator

The Armstrong Oscillator is named for Edwin Armstrong, its inventor. ... A Colpitts oscillator, named after its inventor Edwin H. Colpitts, is one of a number of designs for electronic oscillator circuits. ... Schematic diagram The Hartley oscillator is an LC electronic oscillator that derives its feedback from a tapped coil in parallel with a capacitor (the tank circuit). ...

External links

• EE 322/322L Wireless Communication Electronics —Lecture #24: Oscillators. Clapp oscillator. VFO startup