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RICH DAD POOR DAD BOOK REVIEW

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  RICH  DAD  POOR  DAD  BOOK REVIEW This is amazing book.   • Explodes the myth that you need to earn a high income to become rich • Challenges the belief that your house is an asset • Shows parents why they can't rely on the school system to teach their kids about money • Defines once and for all an asset and a liability • Teaches you what to teach your kids about money for their future financial success It's been nearly 25 years since Robert Kiyosaki’s  Rich Dad Poor Dad  first made waves in the Personal Finance arena. It has since become the #1 Personal Finance book of all time... translated into dozens of languages and sold around the world. Rich Dad Poor Dad  is Robert's story of growing up with two dads — his real father and the father of his best friend, his rich dad — and the ways in which both men shaped his thoughts about money and investing. The book explodes the myth that you need to earn a high income to be rich and explains...
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Ideal Transformer (1-phase) Operation Under Load

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 What is Ideal Transformer ?

An ideal transformer is a transformer with the following assumptions:
  • Permeability of transformer is infinite.
  • Iron loss in the transformer core are zero.
  • Resistance of transformer winding is zero.
  • No magnetic leakage flux, so coefficient of coupling is 1.
  • Magnetization curve of transformer is linear.

Operation of Ideal transformer under load

Schematic diagram of an ideal, 1-phase transformer under load

When a finite impedance load ZL  is connected across the secondary terminals of a 1-phase transformer as shown in above figure, the load current I2  flows through the secondary winding and the load.
load current I2  is given by:-
I2  = V2 / ZL

How will MMFs Produce ?

A voltage source V1  is connected to the primary winding. Due to this voltage V1  primary current I1  flowing through N1  number of turns in the primary winding produces an MMF  N1.I1  which creates the flux Ⲫ in the core. This flux links with the secondary coil and induces an EMF of E2  in the secondary winding. This source of EMF circulates a current I2  through the secondary winding and the load. This current I2  flowing through the secondary winding with N2  number of turns produces an MMF N2.I2  . 
The primary MMF N1.I1  is thus the cause and the secondary MMF N2.I2  is the effect. 

According to Lenz's law, the secondary MMF will try to oppose the primary MMF. In ideal condition, when there is no flux leakage, the two MMFs exactly balance each other, i.e., they are exactly equal in magnitude and opposite in phase.
i.e.       N1 I1 = - N2 I2             
or,       I1 / I2  = - N2 / N1  
or,       I1 = - I2 / a
primary and secondary currents are thus in exact phase opposition.

If the Load current varies:-

When the load current I2  increases due to any changes in load impedance, the secondary MMF N2 I2  also increases. This MMF produces and opposes flux in core that tries to reduce the main mutual flux Ⲫ. As soon as the flux Ⲫ reduces, the self EMF E1  in the primary winding also reduces. Thus, the opposition to the primary supply voltage V1  reduces (remember, at steady operating conditions, V1  is exactly balanced by E1  in an ideal transformer). The supply voltage V1  can now send more current to the primary winding causing I1  to increase and thus the primary MMF N1 I1  is also increased. This increased amount of primary MMF restores the main flux Ⲫ once again to its original value.
The mutual flux Ⲫ in a transformer is thus always more or less held at a constant value.

Opposite process happens when the load current is reduced. Any variations in the load current I2  is thus balanced by a proportional variations in the supply current I1  so as to keep the the main flux Ⲫ constant in the core. The main mutual flux is thus always maintained at a value which ensures that the primary EMF E1  is always equal and opposite to V1  (neglecting voltage drops in the winding of an ideal transformer).
Note that the resultant MMF in a transformer that maintains the mutual flux in the core is due to the combined actions of primary and secondary MMFs.


Phasor diagram of ideal transformer under load:-

Assume the load is R-L load
I2  lagging behind the voltage V2  by the phase angle Ө

Phasor diagram of ideal transformer operation with load


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