Quantcast AMPLIFIER CLASSES OF OPERATION - 14180_18

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
1-6 You might hear that a vacuum tube is a voltage-operated device (since the grid does not need to draw current) while the transistor is a current-operated device. You might agree with this statement, but both the vacuum tube and the transistor are still current-control devices. The whole secret to understanding amplifiers is to remember that fact. Current control is the name of the game. Once current is controlled you can use it to give you a voltage gain or a power gain. This chapter will use transistor amplifiers to present the concepts and principles of amplifiers. These concepts apply to vacuum-tube amplifiers and, in most cases, magnetic amplifiers as well as transistor amplifiers. If you wish to study the vacuum-tube equivalent circuits of the transistor circuits presented, an excellent source is the EIMB, NAVSEA 0967-LP-000-0120, Electronics Circuits. The first amplifier concept that is discussed is the "class of operation" of an amplifier. AMPLIFIER CLASSES OF OPERATION The class of operation of an amplifier is determined by the amount of time (in relation to the input signal) that current flows in the output circuit. This is a function of the operating point of the amplifying device. The operating point of the amplifying device is determined by the bias applied to the device. There are four classes of operation for an amplifier. These are: A, AB, B and C. Each class of operation has certain uses and characteristics. No one class of operation is "better" than any other class. The selection of the "best" class of operation is determined by the use of the amplifying circuit. The best class of operation for a phonograph is not the best class for a radio transmitter. Class A Operation A simple transistor amplifier that is operated class A is shown in figure 1-4. Since the output signal is a 100% (or 360º) copy of the input signal, current in the output circuit must flow for 100% of the input signal time. This is the definition of a class A amplifier. Amplifier current flows for 100% of the input signal. Figure 1-4.—A simple class A transistor amplifier. The class A amplifier has the characteristics of good FIDELITY and low EFFICIENCY. Fidelity means that the output signal is just like the input signal in all respects except amplitude. It has the same


Electrical News
10 Eye-Opening IC Insights
The semiconductor industry will step ahead at a decent 7%...
eetimes.com
EEVblog #708 – Free Energy BULLSHIT!
Are the laws of physics being bent? Dave explains why...
eevblog.com
Increased Functionally Drives Flash Array Adoption
Early all-flash arrays were dedicated to a single application, but...
eetimes.com
New Technology Detects Cyberattacks By Power Consumption
Startup's "power fingerprinting" approach catches stealthy malware within milliseconds in...
eetimes.com
Imagination Sees Life Beyond Games
Imagination Technologies continues to hedge its bets on graphics-based processing,...
eetimes.com
Motion Control Comes to Masses with TI Launchpad
Prototyping of brushless motor control systems has required specialized expertise,...
eetimes.com
Holographic Images for Healthcare
Like a scene from a science fiction film, this new...
eetimes.com
Banking Trojans Disguised As ICS/SCADA Software Infecting Plants
Researcher spots spike in traditional financial malware hitting ICS/SCADA networks...
eetimes.com
Wide-Spread SSD Encryption is Inevitable
As vendors have steadily released self-encrypting SSDs for client devices...
eetimes.com
Obnoxious Lights
Tom Burke continues on his quest to master the Arduino...
eetimes.com
BlackBerry CEO: Net Neutrality For Mobile Apps
CEO John Chen is asking legislators to expand the definition...
eetimes.com
4 Takeaways From Accenture's $14 Trillion IoT Prediction
Accenture's report says the industrial Internet of Things will create...
eetimes.com
French Startup Expands 3D to the Room
With still 26 days to go, Kickstarter project Immersis from...
eetimes.com
Friday Quiz: Inductance and Capacitance in Transmission Lines
High frequencies bring out the worst in components and signal...
eetimes.com
Fraunhofer Develops MEMS Optical Grating for Medium Infrared
The Fraunhofer Institute for Photonic Microsystems IPMS is developing a...
eetimes.com
IoT Hears Two Cellular Calls
2G and LTE standards efforts promise lower cost, lower power...
eetimes.com
Intel, Microsoft, Autodesk Creating Life
Microbial Robotics has created microscopic robots from living viruses (ViruBots)...
eetimes.com
DesignCon: PCB Design Tools Track Covers DDR4, Differential Crosstalk
This DesignCon track explores effective high-speed design and design choices...
eetimes.com
Spectrometer Lights Up IoT, Smartly
Analog circuit, MEMS, and sensors manufacturer AMS announced an integrated...
eetimes.com
Talking Terminations
Random thoughts on series termination and SI....
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 +