Motors and Generators - Part 1 - DC Motors and Generators - 1961 US Army Training Film
Rotating electrical machinery is a part of military equipment. It is a simple blower or a complicated electronic device as missile. They all depending on proper functioning of rotating electrical equipment.
Two types of motors and generators are commonly in use: AC (alternating current) and DC (direct current) motors and generators.
This film demonstrates the principles covering operation of DC motors and generators.
Principles of AC motors and generators are in the part 2:
• Motors and Generators - Part 2 - AC Motors...
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Timeline:
00:26 Application of rotating electrical machines
01:14 Generation of electromotive force (EMF)
03:15 Opposite polarity
03:33 Three factors
The strength of the magnetic field (B)
The length of the conductor cutting the lines of force (l)
Velocity with which the conductor is turning (v)
03:54 Formula for determining the amount of instantaneous EMF
EMF: e= B*l*v
04:42 Conductor motion. Principles of EMF generation.
06:06 Formula for determining the amount of instantaneous EMF when conductor moves in the rotary path: e= B*l*v*sinθ. sinθ - angle formed by the flex line and the motion of the conductor
06:55 Graph of EMF
07:15 Basic operation of an AC generator
07:22 The principles of operation of a DC generator
07:45 Brushes and commutator
07:58 Armature
08:21 Ripple
08:58 DC output
09:21 Adding magnets
09:38 Flatten DC output
09:48 Practical DC generator armature
09:58 Almost pure DC output
10:09 An important problem on the design of generators
10:20 The neutral plane
10:48 Armature reaction
11:30 Sparking interference
11:40 Adjustment of the brush position - the way of maintaining the neutral plane
12:05 The other way of maintaining the neutral plane
12:39 Compensating winding
13:04 Magnetic filed
13:27 The symbol of field winding
13:39 Separately exited generator
13:53 Self exited generator
14:10 Residual magnetism
14:21 Series wound generator
15:03 Load to voltage ratio
15:21 Shunt wound generator
15:59 Compound wound generator
16:40 Generator output characteristics (graphic)
17:27 Conversion of energy
17:37 Experiment on connection of power source to DC generator
18:24 Direction of current flow
19:02 Motion of the conductor
20:27 Examining of DC motor
21:24 Number of loops
22:10 Sparking on DC motor
23:22 Generator action
23:36 Counter electromotive force (CEMF)
24:16 Large motor problem on starting
24:33 Starting boxes
25:36 DC motor windings
26:00 Starting torque and starting current
28:08 The desirable characteristics
28:51 Quick summary
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1961 US Army Training Film