Quantcast HARTLEY OSCILLATOR

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
2-17 Figure 2-12.—Collector current and voltage waveforms of a class C oscillator. HARTLEY OSCILLATOR The HARTLEY OSCILLATOR is an improvement over the Armstrong oscillator. Although its frequency stability is not the best possible of all the oscillators, the Hartley oscillator can generate a wide range of frequencies and is very easy to tune. The Hartley will operate class C with self-bias for ordinary operation. It will operate class A when the output waveform must be of a constant voltage level or of a linear waveshape. The two versions of this oscillator are the series-fed and the shunt-fed. The main difference between the Armstrong and the Hartley oscillators lies in the design of the feedback (tickler) coil. A separate coil is not used. Instead, in the Hartley oscillator, the coil in the tank circuit is a split inductor. Current flow through one section induces a voltage in the other section to develop a feedback signal. Series-Fed Hartley Oscillator One version of a SERIES-FED HARTLEY OSCILLATOR is shown in figure 2-13. The tank circuit consists of the tapped coil (L1 and L2) and capacitor C2. The feedback circuit is from the tank circuit to the base of Q1 through the coupling capacitor C1. Coupling capacitor C1 prevents the low dc resistance of L2 from placing a short across the emitter-to-base junction and resistor RE. Capacitor C3 bypasses the sine-wave signal around the battery, and resistor RE is used for temperature stabilization to prevent thermal runaway. Degeneration is prevented by CE in parallel with RE. The amount of bias is determined by the values of RB, the emitter-to-base resistance, the small amount of dc resistance of coil L1, and the resistance of RE. Figure 2-13.—Series-fed, tuned-base Hartley oscillator.


Electrical News
Transactors -- Expanding the Role of FPGA-Based Prototypes
FPGA-based prototypes offer unbeatable flexibility, capacity, and speed. Extending their...
eetimes.com
Awesome 3D Electronic Sculptures
These little beauties are created using thousands of discrete components...
eetimes.com
Graphene Polymer Speeds Electron Transport
Depositing conducting polymers on graphene gives then highly desirable electrical...
eetimes.com
Vision Explosion Requires Mobile Architecture Rethink
CEVA's Eran Briman examines the explosion in vision processing and...
eetimes.com
ECC Brings Reliability and Power Efficiency to Mobile Devices
Error correcting code increases memory density and bandwidth while maintaining...
eetimes.com
Friday Quiz: Spectrum and Network Measurements
Wireless is everywhere, but not without spectral measurements....
eetimes.com
LTE-U for Small Cells Improves Wi-Fi Environment
In LTE-U, LTE technology over an unlicensed band is paired...
eetimes.com
Web Giants Dictate Road Maps
Big data centers such as Amazon, Google and Facebook are...
eetimes.com
IoT Terrain Still Shifting
The Internet of Things continues to fragment with competing networks...
eetimes.com
Infineon: CAN FD Success Goes at Expense of FlexRay
The faster version of the venerable CAN bus, CAN FD...
eetimes.com
Maker Faire Sydney – Trends in Hardware Innovation Fireside Chat
2014 Sydney Maker Faire Power House Museum 17/8/2014 Trends in...
eevblog.com
Apple's March 9 Event: Is It Time For The Apple Watch?
Apple fans and non-fans alike are waiting to "watch" what...
eetimes.com
Tessera Buys Smart Sensors for Iris Recognition
FotoNation Limited, a wholly owned subsidiary of chip packaging company...
eetimes.com
Hi-Speed Transistors from Liquid Processing
A University of Chicago lab has invented a new kind...
eetimes.com
An Appetizing Archive of Propitious & Pragmatic Resources
EE Times blogger Adam Taylor has created a website containing...
eetimes.com
ESC Boston 2015 Sneak Peek -- Open Source Electromagnetic Trackers
Here's a sneak peek at one of the presentations to...
eetimes.com
Radars Can't Spot Mysterious Drones over Paris
Unidentified drones were spotted in the skies above Paris two...
eetimes.com
18 Views of ISSCC
Engineers showed advances in lower power, higher performance and media-rich...
eetimes.com
IoT Starter Kit Connects Developer to Cloud in Moments
Seeking to simplify the prospect of creating an IoT prototype...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +