Mechanics DC Motors Flashcards
What are the two types of motors?
AC and DC
How is speed controlled on AC motors?
Frequency
How is speed controlled on DC motors?
Voltage/Current
How do you switch from AC power to DC?
Rectifier
How do you go from AC 480V to Ac 240/120V?
Transformer
How do you go from DC power to AC?
Inverter
What are the cons of DC motors?
Complex, costly, and require maintenance
What are the pros to DC motors?
Easy to control speed
What are the 2 types of DC motors?
Brushed and Brushless
What are the 2 types of brushed motors
Permanent Magnet and Wound Field
What are the characteristics of permanent magnet DC motors?
•Magnets fixed in the stator
•Rotating portion is the armature, gets current from carbon brushes, which ride on the commutator.
What are the characteristics of wound field DC motors?
•Stator had poles (windings) that we pass current through to create a magnetic field.
•3 wiring configurations (Series, Shunt, and Compound)
What does Series Wound refer to?
Windings in series with the armature.
What does Shunt Wound refer to?
Windings in parallel with the armature.
What does Compound Wound refer to?
Windings in parallel AND series with the armature.
What are the characteristics of Series Wound DC motors?
•High Torque
•No Speed Control
(Used typically in traction motors/metal rolling)
What are the characteristics of Shunt Wound DC motors?
•Low Torque
•Great Speed Control
•Operate from separate power sources from the armature
What are the characteristics of Compound Wound DC motors?
•Best of both Series, and Shunt
•Speed varies little with load, with the ability to increase torque with heavier load
What are the characteristics of Brushless DC motors?
•Exact opposite of permanent magnet
•Fixed Magnets in rotor
•Capable of high RPMs (Up to 1800)
•20HP and lower
How do you wire a Series Wound motor?
A+ ●●● A-___
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A1 ●●● A2 |
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S1 ●●● S2 |
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S3 ●●● S4___|
How do you wire a Shunt Wound motor?
A+ ●●● A-__
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A1 ●●● A2_|
F+ ●●●F-____
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F1 ●●● F2 |
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F2 ●●● F3__|
How do you wire a Compound Wound motor?
A+ ●●● A-__
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A1 ●●● A2 |
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S1 ●●● S2 |
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S3 ●●● S4_|
F+ ●●●F-____
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F1 ●●● F2 |
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F3●●● F4__|
How do you wire a Series Wound motor? Pt2
A1⚪️A2___S1●●●S2___S3●●●S4
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|____________|A+ A-|___________|
How do you wire a Shunt Wound motor? Pt2
_______________A1⚪️A2_____________
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| F1●●●F2___F3●●●F4 |
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| |_______|F+ F-|________| |
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|____________|A+ A-|______________|
