421022
Mind Map on UNIT 202, created by Lrowlands on 12/06/2013.
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Created by Lrowlands
almost 6 years ago
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UNIT 202
1 Ac Theory
1.1 Star Connection
1.2 Delta Connection
2 Dc Theory
2.1 Current
2.1.1 The Unit is Amperes (A)
2.2 EMF
2.2.1 Unit of EMF is Volts (V)
2.3 Resistance
2.3.1 Measured in OHM'S
2.3.1.1 The Formula Symbol R
2.3.2 Resistors in a series circuit
2.3.2.1 R1
2.3.2.1.1 R2
2.3.2.1.1.1 R3
2.3.2.2 RT= R1 + R2 + R3
3 Motors
3.1 3 Parts on a 3phrase
3.1.1 Stator
3.1.2 Electromagnets
3.1.2.1 Rotor
3.2 single phase motors
3.3 3 Phrase motors
3.4 3 types of Motors
3.4.1 Split Phase
3.4.1.1 Capacitor start/capacitor - run motor
3.4.2 Capacitor
3.5 DC Motors Components
3.5.1 Field - Stays still
3.5.2 Commutator (Attached to the armature)
3.5.2.1 Armature -moving part
3.5.2.2 Flips Polarity on a DC Motors, acts as a switch
3.5.3 Carbon Brush
3.5.3.1 Provide current to the moving part
3.5.3.1.1 Conducts Elecricity
3.5.3.1.2 Self Lubricating
3.5.3.2 Soft
3.5.4 Series
3.5.4.1 Parallel
3.5.4.2 Compound
3.6 DC Motor Components
3.6.1 Poles
3.6.2 Field Windings
3.6.3 Armature
3.6.4 Commutator
3.6.5 Carbon Brushes
3.7 Synchronous Speed (ns)
3.7.1 Speed of the magnetic field in the stator
3.7.2 Ns ( rps ) = F/P
3.7.3 Ns ( rpm ) = 60 X F / P
3.7.4 Nr = Rotor speed
3.7.4.1 Slip = Difference between Ns and Nr
3.7.4.1.1 Per Unit Slip = Ns - Nr / Ns
3.7.4.1.2 % Slip = Ns - Nr / Ns x 100
4 Transformers
4.1 Special Transformers
4.2 Self inductance
4.2.1 Equation for self Inductance :
L X ( L2 - L1 ) / T
4.2.1.1 L = Value of Inductance in Henrys
4.2.1.2 T = Time in seconds
4.2.1.3 L1 and L2 = Values of Current
4.3 Mutual Inductance
5 Prefixs
5.1 Kilo -> k -> 1x10^3
5.2 mega -> M -> 1x10^6
5.3 GIGA -> G -> 1x10^9
5.4 Terra -> T -> 1x10^12
5.5 milli -> m -> 1x10-3
5.6 Micro -> yu -> 1x10-6
5.7 nano -> n -> 1x10-9
5.8 pico -> p -> 1x10-12
5.9 Positive
5.10 Negative
6 Floresent lighting
6.1 Ultra-Violet, Unless
Phosphorus turns into
visible light
6.1.1 Electrodes are parts at the
end of the lights
6.1.2 Gas on the inside
6.2 The Ballast ( Chalk )
6.2.1 Limits The Lamps Operating
Current
6.2.2 Provide the required voltage to
start the lamp
6.2.3 Two Types
6.2.3.1 Electromagnetic
6.2.3.2 Electronic