Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes USAF radar shop Notable Quotes App Notes Calculators Education Engineering Magazines Engineering magazine articles Engineering software Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Stencils for Visio RF & EE Shapes for Word Advertising RF Cafe Homepage Sudoku puzzles Thank you for visiting RF Cafe!
MECA Electronics

Navy Electricity and Electronics Training Series (NEETS)
Module 5 - Introduction to Generators and Motors
Chapter 1:  Pages 1-31 through 1-34

NEETS   Module 5 - Introduction to Generators and Motors

Pages i - ix, 1-1 to 1-10, 1-11 to 1-20, 1-21 to 1-30, 1-31 to 1-34, 2-1 to 2-10, 2-11 to 2-16, 3-1 to 3-10, 3-11 to 3-22, 4-1 to 4-10, 4-11 to 4-18, Index

 

ARMATURE LOSSES - RF Cafe

 
ARMATURE TYPES used in dc generators are the Gramme-ring (seldom used) and the drum-type, used in most applications.
 

ARMATURE TYPES - RF Cafe

1-31


FIELD EXCITATION is the voltage applied to the main field windings. The current in the field coils determines the strength and the direction of the magnetic field.
 
SEPARATELY EXCITED GENERATORS receive current for field coils from an outside source such, as a battery or another dc generator.
 
SELF-EXCITED GENERATORS use their own output voltage to energize field coils.
 
SERIES-WOUND DC GENERATORS have field windings and armature windings connected in series. Outputs vary directly with load currents. Series-wound generators have few practical applications.
 

SERIES-WOUND DC GENERATORS - RF Cafe

 
SHUNT-WOUND DC GENERATORS have field windings and armature windings connected in parallel (shunt). The output varies inversely with load current.
 

SHUNT-WOUND DC GENERATORS - RF Cafe

 
COMPOUND-WOUND DC GENERATORS have both series field windings and shunt field windings. These generators combine the characteristics of series and shunt generators. The output voltage remains relatively constant for all values of load current within the design of the generator. Compound generators are used in many applications because of the relatively constant voltage.
 
 

1-32



 

COMPOUND-WOUND DC GENERATORS - RF Cafe

 
AMPLIDYNES are dc generators that are designed to act as high-gain amplifiers. By short- circuiting the brushes in a normal dc generator and adding another set of brushes perpendicular to the original ones, an amplidyne is formed. Its power output may be up to 10,000 times larger than the power input to its control windings.
 

AMPLIDYNES - RF Cafe

1-33


ANSWERS TO QUESTIONS Q1. THROUGH Q24.

 
A1.     Magnetic induction.
 
A2.     The left-hand rule for generators.
 
A3.     To conduct the currents induced in the armature to an external load.
 
A4.     No flux lines are cut.
 
A5.     A commutator
 
A6.     The point at which the voltage is zero across the two segments.
 
A7.     Two.
 
A8.     Four
 
A9.     By varying the input voltage to the field coils.
 
A10.   Improper commutation.
 
A11.    Distortion of the main field due to the effects of armature current.
 
A12.    To counter act armature reaction.
 
A13.    A force which causes opposition to applied turning force.
 
A14.    Resistance in the armature coils, which increases with temperature.
 
A15.     By laminating the core material.
 
A16.    Drum-type armatures are more efficient, because flux lines are cut by both sides of each coil.
 
A17.    Higher load currents are possible.
 
A18.    Series-wound, shunt-wound, and compound-wound.
 
A19.    Output voltage varies as the load varies.
 
A20.     Voltage regulation.
 
A21.     Parallel operation.
 
A22.     It can serve as a power amplifier.
 
A23.     Gain = output รท input.
 
A24.     The mechanical force applied to turn the amplidyne, and the electrical input signal.
 
 

1-34



NEETS Table of Contents

ERZIA (RF amplifiers, wireless, communications) - RF Cafe RF Cascade Workbook 2018 by RF Cafe
QuinStar Technology (Millimeter Wave Solutions) - RF Cafe Axiom Test Equipment - RF Cafe
About RF Cafe
Kirt Blattenberger - RF Cafe Webmaster
Copyright: 1996 - 2024
Webmaster:
    Kirt Blattenberger,
    BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:  AirplanesAndRockets.com

spacer