Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!

Clapp oscillator

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, thus also called LC oscillator.
It was published by James K. Clapp in 1948[1]. According to Vackár[2], oscillators of this kind were independently discovered by several authors, and one developed by G.G. Gouriet was in Operation at the BBC since 1938.

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).

A Clapp circuit is often preferred over a Colpitts circuit for constructing a variable frequency oscillator (VFO). 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.

Visit Here for more.

 

More Articles to Read

Estimating Power for ADSP-BF561 Blackfin® Processors
Estimating Power for ADSP-BF561 Blackfin® Processors
Teach Your Arduino to Switch Itself Off!
Teach Your Arduino to Switch Itself Off!
Control a tracked robot with your mind (or joystick)
Control a tracked robot with your mind (or joystick)
A 400W (1kW Peak) 100A electronic load using linear MOSFETs
A 400W (1kW Peak) 100A electronic load using linear MOSFETs
Shirt Pocket Transceiver with the Si5351 and OLED
Shirt Pocket Transceiver with the Si5351 and OLED
All metal C930e webcam
All metal C930e webcam
The Soldering Tools That Make Your Life Easier
The Soldering Tools That Make Your Life Easier
App note: Operation evaluation of ultra low ON resistance MOSFET supporting quick charge for 1 c ...
App note: Operation evaluation of ultra low ON resistance MOSFET supporting quick charge for 1 cell Lithium ion battery protection
Synthesized Sidetone
Synthesized Sidetone
App note: Application precautions: Power MOSFET application notes
App note: Application precautions: Power MOSFET application notes

Top




Shares