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mechanical
electrical
hydraulic
Thermal
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Why I must think of analogy
?!!! !!!!!!!!
Finding out the transfer function
withoutneeding to write system equations.
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BETWEEN
MECHANICALELECTRICAL
SYSTEMS
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Electrical Mechanical
Two types of analogy
1-Electrical to Mechanical -classical
(Force-Voltage).2-Electrical to
MechanicalMobility(Force-Current).
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
1-Force-Voltage analogy
Current velocity.Both are motions of some kind
voltage force .
What pushes the current through a resistor.Resistors
Dampers.
Resist motion just like resistors resists current
(both are energy dissipating elements)
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Mass inductor
Springs capacitors.
Running current in an capacitor build up voltage.
Having velocity compressing a spring
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Spring capacitor
F=Kx=vdt v=(1/c) idtSo
X 1/c
Anoter form
V=(1/k) (df/dt) i=c(dv/dt)
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Make sense
i=c(dv/dt)V=(1/k) (df/dt)
With a given current ,for a
given time,smaller capacitor will
build up more voltage
For a given velocity
smaller spring willbuild
less force
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Procedure for Conversion from Electrical to Mechanical
Every loop in the electrical circuit becomes a point in the
mechanical
system.
1-Label all currents. Choose currents so that only one current
flows through
inductors.
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
2- Write a loop equations for each loop.
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
3- Re-write the equations using analogs( with each
electrical loop being replaced by a position)
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
2-Force-Current analogy
Current force.
voltage . Velocity.
Resistors Lubricity, 1/B
(Inverse friction)
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Capacitance mass
mass energy
.mv2
Inductance. Compliance, 1/K
(Inverse spring constant) .
.
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Procedure for Conversion from Electrical to Mechanical
To apply this analogy, every node in the electrical circuit
becomes
a point in the mechanical system.
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
1-Start with an electrical circuit. Label all node voltages.
2-Write a node equations for each node voltage
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
3-Re-write the equations using analogs (make each electrical
node being replaced by a position).
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
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ANALOGY BETWEEN MECHANICAL AND ELECTRICAL SYSTEMS
Mechanical to Electrical
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Thank youfor attention
By:-
