Post on 17-Jul-2015
Basic electric circuits & components1. Introduction
2. SI units & common prefixes
3. Electrical circuits
4. Direct current & alternating Current
5. Resistors, Capacitors & Inductors
6. Ohm’s Law & Kirchoff’s Law
7. Power dissipation in Resistors
8. Resistors circuit in Series & Parallel
9. Resistive potential dividers
10. Sinusoidal wave
11. Circuits symbols
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SI units
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Common Prefixes
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Electric Circuits Electric Charge
An amount of electrical energy
Can be positive or negative
Electric Current
• A flow of electrical charge often a flow of electrons
• Conventional current is in the direction to a flow of electrons
Current flow in a circuit
• A sustained current needs a to complete a circuit
• Also require to charge flow
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Electromotive force & Potential difference
• The similar that causes a current to flow as an e.m.f
• The represents the energy introduced into the circuit by a battery or generator
• This results in on electric potential at each point in the circuit
• Between any two point in the circuit there may exit
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Potential Difference
• Both e.m.f and potential difference are measured n volts
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AC & DCAC• When current vary with time they may be unidirectional or
alternating
• When the direction of the current periodically changes this in aalternating current (AC)
DC• Current in electrical circuits may be constant it may be vary with
time
• When the current flowing in a conductor always flows in the samedirection this is a direct current (DC)
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Resistor, Capacitor & Inductor
Resistors• The oppose flow of electricity
• Measured in ohms (Ω)
Capacitor• Provide capacitance
• They store energy in a electric field
• Measured in Farads (F)
Inductor• Provide inductance
• They store energy in a magnetic field
• Measured in Henry(H)Done By Mahe
Ohm’s Law The current flowing in a conductor is directly proportional to
applied voltage V & inversely proportional to the resistance R
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Kirchhoff's Current Law
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Kirchhoff's Voltage Law
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Power Dissipation in Resistor The instantaneous power dissipation P of a resistor is given be the product
of the voltage across it and the current passing through it combining the revalue with Ohm’s Law
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Resistor in Series Circuit
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Resistor in Parallel Circuit
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Resistive Potential Difference
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Sinusoidal Quantities Length of time between corresponding points in successive cycle in a
period T
Number of cycle passes per second is the frequency “f” unit Hz
Formula
f=1/T
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Electrical Circuit Symbol’s
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AC & DC Supply
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Motor
It convert’s a Electrical Energy into a Mechanical Energy
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Speed Ns
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Core
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Stator
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Rotor
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Types of MoTor’s
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AC Motor
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DC Motor
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Motor Construction
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Commutator
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Star-Delta Circuit
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